&EPA
            United States
            Environmental Protection
            Agency
             Office of
             Research and Development
             Washington, DC 20460
EPA/600/4-79/020
March 1983
Methods for
Chemical Analysis of
Water and Wastes

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U S. Environmental Protection Agency
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                                                 EPA-600/4-79-020
     METHODS FOR  CHEMICAL ANALYSIS
            OF WATER AND WASTES
                    March 1983
               Second Printing June 1982
ENVIRONMENTAL MONITORING AND SUPPORT
                LABORATORY
  OFFICE OF RESEARCH AND DEVELOPMENT
 U S ENVIRONMENTAL PROTECTION AGENCY
             CINCINNATI, OHIO 45268
                                           Printed on Recycled Paper _

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                                 DISCLAIMER
The mention of trade names or commercial products in this manual is for illustration purposes, and
does not constitute endorsement or recommendation for use by the U S Environmental Protection
Agency
                                         n

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                                     FOREWORD
 The accomplishment of our objective m protecting the environment requires a reliable assessment of
 the present condition and a determination of the effectiveness of corrective measures  Decisions
 which must be made on the need for pollution abatement and the most efficient means of achieving
 environmental quality depend upon the availability of sound data Test procedures for measurement
 of the presence and concentration of substances hazardous to human health as well as an evaluation
 of the quality of the environment are essential to satisfactory decision-making

 This manual of chemical methods was prepared by the staff of the Environmental Monitoring and
 Support Laboratory of the Environmental Research  Laboratory, Cincinnati to provide procedures
 for monitoring water supplies,  waste discharges, and the quality of ambient waters  These test
 methods have been carefully selected to  meet the  needs of Federal Legislation and to provide
 guidance to laboratories engaged in protecting human health and the aquatic environment The
 contributions and counsel of scientists in other EPA laboratories are gratefully acknowledged

 Test procedures contained herein, that are approved for water and waste monitoring under the Safe
 Drinking Water Act (SDWA) and the National Pollutant Discharge Elimination System (NPDES),
 of PL 92-500 are so indicated at the bottom of each title page  These approved methods are also
 recommended for ambient monitoring needs of Section 106 and 208 of PL 92-500  Methods without
 this stated approval are presented for information only Correspondence on these methods is invited
    )
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                                   ABSTRACT
This manual provides test procedures approved for the monitoring of water supplies, waste
discharges, and ambient waters, under the Safe Drinking Water Act, the National Pollutant
Discharge Elimination System, and Ambient Monitoring Requirements of Section 106 and 208
of Public Law 92-500 The test methods have been selected to meet the needs of federal legislation
and to provide guidance to laboratories engaged in the protection of human health and the
aquatic environment
                                         IV

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                                 CONTENTS
Foreword
Abstract

Introduction

Sample Preservation

EPA Quality Assurance Coordinators
                             100  Physical Properties
     Color
          Colonmetnc, ADMI
          Colonmetnc, Platinum-Cobalt
          Spectrophotometnc

     Conductance
          Specific Conductance

     Hardness, Total (mg/1 as CaCO3)
          Colonmetnc, Automated EDTA
          Titnmetnc,  EDTA
     Odor
     pH
Threshold Odor (Consistent Series)

Electrometnc
Electrometric (Continuous Monitoring)
    Residue
         Filterable
              Gravimetric, Dried at  180C
         Non-Filterable
              Gravimetric, Dried at  103-105C
         Total
              Gravimetric, Dried at  103-105C
         Volatile
              Gravimetric, Ignition at 550C
         Settleable  Matter
              Volumetric, Imhoff Cone
                                                                      111

                                                                      IV
                                                                      *,
                                                                    xni

                                                                     XV

                                                                     XX
                                                           Method 110 1
                                                           Method 1102
                                                           Method 1103
                                                           Method  120 1
                                                           Method 130 1
                                                           Method 1302
Method 140 1

Method 150 1
Method 150 2
                                                          Method 1601

                                                          Method 1602

                                                          Method 1603

                                                          Method 1604

                                                          Method 1605

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Temperature
     Thermometnc

Turbidity
     Nephelometnc
Atomic Absorption Methods
                             200   Metals
Inductively Coupled Plasma	

Aluminum
     AA, Direct Aspiration
     AA, Furnace

Antimony
     AA, Direct Aspiration
     AA, Furnace  	

Arsenic
     AA, Furnace
     AA, Hydride
     Spectrophotometnc, SDDC
     Digestion Method for Hydride and SDDC

Barium
     AA, Direct Aspiration
     AA, Furnace

Beryllium
     AA, Direct Aspiration
     AA, Furnace

Boron
      Colonmetnc, Curcumm

 Cadmium
      AA, Direct  Aspiration
      AA, Furnace  .

 Calcium
      AA, Direct  Aspiration
      Titnmetnc,  EDTA
Method  170 1


Method  1801



 Section  2000

 Method 200 7
Method 202 1
Method 202 2
 Method 204 1
 Method 2042
 Method 206 2
 Method 206 3
 Method 2064
 Method 206 5
 Method 208 1
 Method 208 2
 Method 210 1
 Method 2102
 Method 212 3
 Method  213 1
 Method  213 2
 Method 215 1
 Method 215 2
                                  VI

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Chromium
     AA, Direct Aspiration
     AA, Furnace
     Chelation-Extraction
     Hexavalent, Chelation-Extraction
     Hexavalent, Dissolved

Cobalt
     AA, Direct Aspiration
     AA, Furnace

Copper
     AA, Direct Aspiration
     AA, Furnace

Gold
     AA, Direct Aspiration
     AA, Furnace

Indium
     AA, Direct Aspiration
     AA, Furnace
Iron
Lead
AA, Direct Aspiration
AA, Furnace

AA, Direct Aspiration
AA, Furnace
Magnesium
     AA, Direct Aspiration

Manganese
     AA, Direct Aspiration
     AA, Furnace

Mercury
     Cold Vapor, Manual
     Cold Vapor, Automated
     Cold Vapor, Sediments
                                                            Method  218 1
                                                            Method  218 2
                                                            Method  218 3
                                                            Method  2184
                                                            Method 2185
                                                            Method  219 1
                                                            Method  2192
                                                            Method  220 1
                                                            Method  2202
                                                            Method  231 1
                                                            Method  231 2
                                                            Method 235 1
                                                            Method 235 2
Method 236 1
Method 236 2

Method 239 1
Method 239 2
                                                            Method 242 1
                                                            Method 243 1
                                                            Method 243 2
                                                            Method 245 1
                                                            Method 245 2
                                                            Method 245 5
                                  Vll

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Molybdenum
     AA, Direct Aspiration
     AA, Furnace

Nickel
     AA, Direct Aspiration
     AA, Furnace

Osmium
     AA, Direct Aspiration
     AA, Furnace

Palladium
     AA, Direct Aspiration
     AA, Furnace

Platinum
     AA, Direct Aspiration
     AA, Furnace

Potassium
     AA, Direct Aspiration

Rhenium
     AA, Direct Aspiration
     AA, Furnace

Rhodium
     AA, Direct Aspiration
     AA, Furnace

Ruthenium
     AA, Direct Aspiration
     AA, Furnace

Selenium
     AA, Furnace
     AA, Hydride
Silver
     AA, Direct Aspiration
     AA, Furnace
 Method 246 1
 Method 246 2
 Method 249 1
 Method 249 2
 Method 252 1
 Method 252 2
 Method 253 1
 Method 253 2
 Method 255 1
 Method 255 2
 Method 258 1
 Method 264 1
 Method 264 2
 Method 265 1
 Method 265 2
. Method 267 1
 Method 267 2
 Method 270 2
 Method 2703
  Method 272 1
  Method 272 2
                                  Vlll

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Sodium
     AA, Direct Aspiration
     AA, Furnace

Thallium
     AA, Direct Aspiration
     AA, Furnace
Tin
     AA, Direct Aspiration
     AA, Furnace
Titanium
     AA, Direct Aspiration
     AA, Furnace

Vanadium
     AA, Direct Aspiration
     AA, Furnace
Zinc
     AA, Direct Aspiration
     AA, Furnace

                     300  Inorganic, Non-metalhcs

Acidity
     Titnmetnc
     Titnmetric (acid rain)          ...

Alkalinity
     Titnmetnc (pH  4 5)
     Colonmetnc, Automated Methyl Orange

Bromide
     Titnmetnc

Chlonde
     Colonmetnc, Automated Ferncyamde, AA I
     Colonmetnc, Automated Ferncyamde, AA II
     Titnmetnc, Mercunc  Nitrate

Chlonne,  Total Residual
     Titnmetnc, Amperometnc
     Titnmetnc, Back-Iodometnc
Method 273 1
Method 273 2


Method 279 1
Method 279 2
Method 282 1
Method 2822
Method 283 1
Method 283 2
Method 286 1
Method 286 2
Method 289 1
Method 289 2
Method 305 1
Method 305 1
Method 310 1
Method 3102
Method 320 1
Method 325 1
Method 3252
Method 325 3
Method 330 1
Method 3302
                                  IX

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     Titrimetric, lodometric [[[ Method 330.3
     Titrimetric, DPD-FAS .................................................. . ................... .. Method 330.4
     Spectrophotometric, DPD [[[ Method 330.5
                                                                 ;     i    ,.-,' #
Cyanide                                                              -;
     Amenable to  Chlorination
          Titrimetric, Spectrophotometric ................................................ Method 335.1
     Total
          Titrimetric, Spectrophotometric ................................................ Method 335.2
          Colorimetric, Automated UV...., ..... . ........ ....... ................. ........ Method 335.3

Fluoride
     Colorimetric,  SPADNS with Bellack
       Distillation [[[ ....... ..... . ..... Method 340.1
     Potentiometric, Ion Selective Electrode ............................................. Method 340.2
     Colorimetric,  Automated Complexone .................. ..... . ....................... Method 340.3

Iodide
     Titrimetric [[[ .Method 345.1

Nitrogen                                                                    t;f
     Ammonia
          Colorimetric, Automated Phenate ............................... . ............ Method 350.1
          Colorimetric; Titrimetric;  Potentiometric -
            Distillation Procedure [[[ Method 350.2
          Potentiometric,  Ion  Selective Electrode ................................... Method 350.3
Kjeldahl, Total
     Colorimetric,  Automated Phenate
     Colorimetric,  Semi-Automated
       Block Digester AAII
     Colorimetric;  Titrimetric; Potentiometric
     Potentiometric, Ion Selective Electrode
     Nitrate
           Colorimetric, Brucine.
     Nitrate-Nitrite
           Colorimetric, Automated Hydrazine
             Reduction	,	
           Colorimetric, Automated Cadmium Reduction
           Colorimetric, Manual Cadmium Reduction ......
                                                                 Method 351.1

                                                                 Method 351.2
                                                                 Method 351.3

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   Nitrite
          Spectrophotometnc
Oxygen, Dissolved
     Membrane Electrode
     Modified Wmkler (Full Bottle Technique)

Phosphorus
     All Forms
          Colonmetric,  Automated,  Ascorbic Acid
          Colonmetnc,  Ascorbic Acid,
            Single Reagent
          Colonmetnc,  Ascorbic Acid,
            Two Reagent
     Total
          Colonmetnc,  Automated,  Block  Digester, AA II

Silica, Dissolved
     Colonmetnc

Sulfate
     Colonmetnc, Automated Chloramlate
     Colonmetnc, Automated Methyl Thymol Blue, AA II
     Gravimetnc
     Turbidimetric

Sulfide
     Titnmetric, Iodine
     Colonmetnc, Methylene Blue

Sulfite
     Titnmetric
                            400  Orgamcs
Biochemical Oxygen Demand
     BOD (5 day, 20C)
Chemical Oxygen Demand
     Titnmetric, Mid-Level
     Titrimetric, Low  Level
     Titnmetric, High Level  for Saline Waters
     Colonmetnc, Automated, Manual
Method 354 1
Method 360 1
Method 3602
Method 365 1

Method 365 2

Method 365 3

Method 3654


Method 370 1
Method 375 1
Method 375 2
Method 375 3
Method 375.4
Method 376 1
Method 3762
Method 377 1
Method 405 1
Method 410.1
Method 4102
Method 410 3
Method 4104
                                  XI

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Oil and Grease, Total  Recoverable
     Gravimetric, Separatory Funnel Extraction                     Method 413 1
     Spectrophotometnc, Infrared                                  Method 413 2

Organic Carbon, Total
     Combustion or Oxidation                                    Method 415 1
     UV Promoted, Persulfate Oxidation.                          Method 4152

Petroleum Hydrocarbons, Total,  Recoverable
     Spectrophotometnc, Infrared                             .     Method 418 1

Phenolics, Total Recoverable
     Spectrophotometnc, Manual 4-AAP with Distillation    .       Method 420 1
     Colonmetnc, Automated 4-AAP with Distillation               Method 4202
     Spectrophotometnc, MBTH with Distillation                   Method 420 3

Methylene Blue Active Substances (MBAS)
     Colonmetnc .                                               Method 425 1

NTA
     Colonmetnc, Manual,  Zmc-Zmcon                       .     Method 4301
     Colonmetnc, Automated, Zinc-Zmcon,                        Method 430 2
                                  Xll

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                                 INTRODUCTION
                                                                    j

NO TL  Since the first printing of this edition in March 1979, various editorial errors have been
        brought to  our attention which have  been corrected  in this second printing  In
        addition, it has been found necessary to add to this printing an updated preservation
        and holding times table (Table 1), as well as six new methods  They are undeTpH,
        Llectrome tries (continuous  monitoring), Method 1502, under Metals, Inductively
        Coupled Plasma, 200 7, under Metals/Chromium  Hexavalent, Dissolved, Method
        218 5, under Metals/Sodium AA,  Furnace, ^Method 2732, under Inorganic, non-
        metalhcslAcidity Titnmetnc(acid ram), Method305 1, and under Organics, Organic
        Carbon, Total UV Promoted, Persulfate, Oxidation, Method 415 2
        These additions have been made so as to keep users of the manual current with the
        procedures the Agency uses in determining compliance with applicable  water and
        effluent standards it has established

        Persons who already possess a copy of the 1979 edition of the manual and who wish to
        update it by including the cited additions need not request another copy The new
        material is available as a separate volume, entitled, "Technical Additions to Methods
        for Chemical Analysis of Water and Wastes, LPA-600/4-79-020," LPA-600/4-82-055,
        from ORD Publications, CLRI, U S Environmental Protection Agency, Cincinnati,
        OH 45268

This third edition of "Methods for Chemical Analysis of Water and Wastes" contains the chemical
analytical  procedures used in U S Environmental  Protection Agency (EPA) laboratories for the
examination of ground and surface waters,  domestic and industrial waste effluents, and treatment
process samples Except where noted under "Scope and Application", the methods are-applicable to
both water and wastewaters, and both fresh and saline water samples The manual provides test
procedures for the measurement  of physical,  inorganic, and selected organic constituents and
pirameters Methods for pesticides, industrial organic waste materials, and sludges are given in other
publications of the Agency The methods were chosen through the  combined efforts of the EPA
Regional Quality Assurance Coordinators, the staff of the Physical and Chemical Methods Branch,
Environmental Monitoring and Support Laboratory, and other senior chemists in both federal and
state laboratories  Method selection was based on the following criteria

     (1)  The method  should measure the desired  property or constituent with  precision,
          accuracy, and specificity sufficient to meet the data needs of EPA, in the presence of the
          interfering materials encountered in water and waste samples
     (2)  The procedure should utilize the  equipment and skills available in modern water
          pollution control laboratories
     (3)  The selected method is in use in many laboratories or has been sufficiently tested  to
          establish its validity
     (4)  The method should be rapid enough to permit routine use for the examination of a large
          number of samples
                                         Xlll

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Instrumental methods have been selected in preference to manual  procedures because  of the
improved speed, accuracy, and precision  In keeping with this policy, procedures for the Techmcon
AutoAnalyzer  have been  included  for laboratories  having  this equipment available  Other
continuous flow automated systems using these identical procedures are acceptable

Intralaboratory and mterlaboratory precision and accuracy statements are provided where such data
are available These mterlaboratory statements are derived from mterlaboratory studies conducted
by the  Quality Assurance Branch,  Environmental  Momtonng  and Support Laboratory, the
American Society for Testing Materials, or the Analytical Reference Service of the US Public Health
Service, DHEW These methods may be used for measuring both total and dissolved constituents of
the sample When the dissolved concentration is to be determined, the sample is filtered through a
0 45-micron membrane filter and the filtrate analyzed by the procedure specified  The sample should
be filtered as soon as possible after it is collected, preferably in the field Where field filtration is not
practical, the sample should be filtered as soon as it is received in the laboratory

Many water and waste samples are unstable  In situations where the interval between sample
collection and analysis is long enough to produce changes in either the concentration or the physical
state of the constituent to be measured, the preservation practices in Table I are recommended

This manual is a  basic reference for  monitoring water  and wastes in  compliance  with the
requirements of the Federal Water Pollution Control Act Amendments of 1972 Although other test
procedures may be used, as provided in the Federal Register issue of October 16,  1973 (38FR 28758)
and  in subsequent amendments, the methods described in this manual will  be used by the
Environmental Protection Agency in determining compliance with applicable water and effluent
standards established by the Agency

Although a sincere effort has been made to select methods that are applicable to the widest range of
sample types, significant interferences may be encountered in certain isolated samples  In these
situations, the analyst will be providing a valuable service to EPA by defining the nature of the
interference with the  method and bringing this information  to  the attention  of  the  Director,
Environmental Momtonng and Support Laboratory, through the appropriate Quality Assurance
Coordinator
                                           X1.V

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                            SAMPLE  PRESERVATION
Complete and unequivocal preservation of samples, either domestic sewage, industrial wastes, or
natural waters, is a practical impossibility  Regardless of the nature of the sample, complete stability
for every constituent can never be achieved  At best, preservation techniques can only retard the
chemical and biological changes that inevitably continue after the sample is removed from the parent
source The changes that take place m a sample are either chemical or biological In the former case,
certain changes occur in the chemical structure of the constituents that are a function of physical
conditions Metal cations may precipitate as hydroxides or form complexes with other constituents,
cations or anions  may change valence states under certain reducing or oxidizing conditions, other
constituents may dissolve or volatilize with the passage of time Metal cations may also adsorb onto
surfaces (glass, plastic, quartz, etc ), such as, iron and lead  Biological  changes taking place in a
sample may change the valence of an element or a radical to a different valence Soluble constituents
may be converted to organically bound materials in cell structures, or cell lysis may result in release
of cellular material into solution  The well known nitrogen and phosphorus cycles are examples of
biological influence on sample composition Therefoie, as a general rule, it is best to analyze the
samples as soon as possible after collection This is especially true when the analyte concentration is
expected to be m the low ug/1 range

Methods of preservation are relatively limited and are intended generally to (1) retard biological
action, (2) retard hydrolysis  of chemical compounds and complexes, (3)  reduce volatility of
constituents, and  (4) reduce absorption effects Preservation  methods  are generally limited to pH
control, chemical addition, refrigeration, and freezing

The recommended preservative for various constituents is given in Table 1 These choices are based
on the  accompanying references and on information supplied by  various Quality  Assurance
Coordinators  As  more data become available, these recommended holding times will be adjusted to
reflect new information Other information provided in the table is an estimation of the volume of
sample required for the analysis,  the suggested type of container, and the maximum recommended
holding times for samples properly preserved
                                           xv

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                         TABLE 1
RECOMMENDATION FOR SAMPLING AND PRESERVATION
     OF SAMPLES ACCORDING TO MEASUREMENT

Measurement
100 Physical Properties
Color
Conductance
Hardness
Odor
pH
Residue
Filterable
Non-
Filterable
Total
Volatile
Settleable Matter
Temperature
Turbidity
200 Metals
Dissolved
Suspended
Total
Vol
Req
(ml)
50
100
100
200
25

100
100
100
100
1000
1000
100

200
200
100

Container2

P,G
P,G
P,G
G only
P,G

P,G
P,G
P,G
P,G
P,G
P,G
P,G

P,G

P,G

Preservative3''

Cool, 4C
Cool, 4C
HNO3 to pH<2
Cool, 4C
None Req

Cool, 4C
Cool, 4C
Cool, 4C
Cool, 4C
Cool, 4C
None Req
Cool, 4C

Filter on site
HNO3 to pH<2
Filter on site
HNO3 to PH<2
                                                      Holding
                                                       Time5
                                                         4.8 Hrs

                                                         28 Days

                                                         6 Mos


                                                         24 Hrs

                                                         Analyze
                                                         Immediately


                                                         7 Days


                                                         7 Days

                                                         7 Days

                                                         7 Days

                                                         48 Hrs

                                                         Analyze
                                                         Immediately
                                                         48 Hrs



                                                         6 Mos
                                                         6 Mos

                                                         6 Mos
                                                             (8)
                           XVI

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TABLE 1 (CONT)
Vol
Req
Measurement (ml)

Chromium*6
Mercury
Dissolved
Total
300 Inorganics, Non-Metalhcs
Acidity
Alkalinity
Bromide
Chloride
Chlorine
Cyanides

Fluoride
Iodide
Nitrogen
Ammonia
Kjeldahl, Total
Nitrate plus Nitrite
Nitrate9
Nitrite

200
100
100
100
100
100
50
200
500

300
100

400
500
100
100
50
Container2 Preservative3'4

P,G
P,G
P,G
P,G
P,G
P,G
P,G
P,G
P,G

P,G
P,G

P,G
P,G
P,G
P,G
P,G
f f
Cool, 4C
Filter
HNO3 to pH<2
HN03 to pH<2
Cool,4C
Cool, 4C
None Req
None Req
None Req
Cool, 4C
NaOH to pH >12
0 6g ascorbic acid6
None Req
Cool, 4C

Cool,4C
H2SO4 to pH<2
Cool, 4C
H2SO4 to pH<2
Cool, 4C
H2SO4 to pH<2
Cool, 4C
Cool, 4C
Holding
Time5
i
24Hrs
28 Days
28 Days
14 Days
14 Days
28 Days
28 Days
Analyze
Immediately
14 Days7

28 Days
24 Hrs

28 Days
28 Days
28 Days
48 Hrs
48 Hrs
      xvu

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TABLE 1 (CONT)


Measurement
Dissolved Oxygen
Probe

Wmkler

Phosphorus
Ortho-
phosphate,
Dissolved
Hydrolyzable

Total

Total,
Dissolved

Silica
Sulfate
Sulfide



Sulfite
400 Orgamcs
BOD
COD

Oil & Grease

Organic carbon

Phenohcs
Vol
Req
(ml)

300

300



50

50

50

50


50
50
500



50

1000
50

1000

25

500


n
Container

G bottle and top

G bottle and top



P,G

P,G

P,G

P,G


P only
P,G
P,G



P,G

P,G
P,G

G only

P,G

G only


Preservative3'4

None Req

Fix on site
and store
in dark

Filter on site
Cool, 4C
Cool, 4C
H2SO4 to pH<2
Cool, 4C
H2SO4 to pH<2
Filter on site
Cool, 4C
H2SO4 to pH<2
Cool, 4C
Cool, 4C
Cool, 4C
add 2 ml zinc
acetate plus NaOH
topH>9
None Req

Cool, 4C
Cool, 4C
H2SO4 to pH<2
Cool, 4C
H2SO4 to pH<2
Cool, 4C
H2SO4 or HC1 to pH<2
Cool, 4C

Holding
Time5

Analyze
Immediately
8 Hours



48 Hrs

28 Days

28 Days

24 Hrs


28 Days
28 Days
7 Days



Analyze
Immediately
48 Hrs
28 Days

28 Days

28 Days

28 Days
                 to pH <2
      XVlll

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                                TABLE  1 (CONT)


                          Vol
                          Req                                              Holding
   Measurement         (ml)    Container2   Preservative3'4            Time5


   MBAS                  250     P,G             Cool, 4C                     48 Hrs

   NTA                    50     P,G             Cool, 4C                    24 Hrs


1    More specific instructions for preservation and sampling are found with each procedure as
     detailed in this manual A general discussion on sampling water and industrial wastewater may
     be found in ASTM, Part 31, p  72-82 (1976) Method D-3370

2    Plastic  (P) or Glass (G) For metals, polyethylene with a polypropylene cap (no liner) is
     preferred

3    Sample preservation should be performed immediately upon sample collection For
     composite samples each aliquot should be preserved at the time of collection When use of
     an automated sampler makes it impossible to preserve each aliquot, then samples may be
     preserved by maintaining at 4C until compositing and sample splitting is completed

4    When any sample is to be shipped by common carrier or sent through the United States
     Mails,  it must comply with the Department of Transportation Hazardous Materials
     Regulations (49 CFR Part 172) The person offering such material for transportation is
     responsible for ensuring such compliance For the preservation requirements of Table 1,
     the Office of Hazardous  Materials,  Materials Transportation Bureau, Department of
     Transportation has determined that the Hazardous Materials Regulations do not apply to
     the following materials Hydrochloric acid (HC1) in water solutions at concentrations of
     0 04% by weight or less (pH about 1 96 or greater), Nitric acid (HNO3) in water solutions at
     concentrations of 0 15% by weight or less (pH about 1 62 or greater), Sulfunc acid (H2SO4)
     in water solutions at concentrations of 0  35% by weight or less (pH about 1  15 or greater),
     Sodium hydroxide (NaOH) in water solutions at concentrations of 0 080% by weight or
     less (pH about 12 30 or less)

5    Samples should be analyzed as soon as possible after collection The times listed are the
     maximum times that samples may be held before analysis and still considered valid
     Samples may be held for longer periods only if the permittee, or monitoring laboratory,
     has data on file to show that the specific types of sample under study are stable for the
     longer  time, and has received a variance from the Regional Administrator  Some samples
     may not be stable for the maximum time period  given in the table  A  permittee, or
     monitoring laboratory, is obligated to hold the sample for a shorter time if knowledge
     exists to show this is necessary to  maintain sample stability

6    Should only be used in the presence of residual chlorine
                                         xix

-------
Maximum holding time is 24 hours when sulfide is present Optionally, all samples may
be tested with lead acetate paper before the pH adjustment in order to determine if sulfide
is piesent If sulfide is present, it can be removed by the addition of cadmium nitrate
powder until a negative spot test is obtained The sample is filtered and then NaOH is
added to pH 12

Samples should be filtered immediately on-site before adding preservative for dissolved
metals

For samples fiom non-chlorinated drinking water supplies cone HzSO4 should be added
to lower sample pH to less than 2 The sample should be analyzed before 14 days
                                    x,x

-------
                   ENVIRONMENTAL  PROTECTION AGENCY
            REGIONAL QUALITY  ASSURANCE COORDINATORS
REGION I

Warren H Oldaker
Central Regional Laboratory
Environmental Services Division
60 Westview Street
Lexington, MA 02173
FTS 671-6700
COML 617-671-6700

REGION II

Gerald F McKenna
Research and Quality Assurance
 Branch
Environmental Services Division
Edison, NJ 08837
FTS 340-6645
COML 201-321-6645

REGION HI

Charles Jones, Jr
(3SA60)
Water Quality Monitoring Branch
Environmental Services Division
6th & Walnut Streets, Curtis Bldg
Philadelphia, PA 19106
FTS 597-9162
COML 215-597-9162

REGION IV

Wade Knight
Laboratory Services Branch
Environmental Services Division
College Station Road
Athens, GA 30613
FTS 250-3165
COML  404-546-3165
REGION V

David Payne
Quality Assurance Office
Environmental Services Division
536 South Clark Street
Chicago, IL 60605
FTS 353-7712
COML  312-353-7712

REGION VI

El oy R Lozano
Environmental Services Division
1201 Elm St, First Int'l Bldg
Dallas, TX 75270
FTS 729-2697
COML  214-767-2697
REGION VII

Charles P Hensley
Laboratory Branch
Environmental Services Division
25 Funston Road
Kansas City, KS 66115
FTS 758-4285
COML  816-374-4285
REGION VIII

Juanita Hillman
Environmental Services Division
Lincoln Tower Bldg , Suite 900
1860 Lincoln Street
Denver, CO 80295
FTS 327-4935
COML 303-837-4935
REGION IX

Ho Lee Young
Office of Quality Assurance
 and Monitoring Systems
215 Fremont Street
San Francisco, CA 94105
FTS  454-8002
COML 415-556-8002

REGION X

Barry Townes
Environmental Services Division
1200 Sixth Avenue
Seattle, WA 98101
FTS  399-1675
COML 206-442-1675
                                              XXI

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                                       COLOR

                       Method 110.1  (Colorimetric,  ADMI)

                                                                     STORET  NOS.
                                                                    00082 at pH  7.6
                                               00083 at ORIGINAL  SAMPLE  pH

     Scope and Application
     1 1  This method is applicable to colored waters and waste that have color characteristics
          significantly different from the yellow platinum-cobalt standard
     12  A working range of 25 to 250 color units is recommended Sample values above 250 units
          may be determined by quantitative dilution
     Summary of Method
     2 1  This method is an extension of the Tnstimulus Filter Method1 Tnstimulus values are
          converted to an ADMI single number color difference, of the same magnitude assigned
          to platinum-cobalt standards, using the Adams Nickerson Color Difference (DE)
     22  Tnstimulus  values obtained by  Spectrophotometnc Method 204B1 may be used to
          calculate ADMI values as outlined m this procedure under Calculation 9 2
     Interferences
     3 1  Since very slight amounts of turbidity interfere with the determination, turbid samples
          must be filtered prior to analysis  The optimum filter media to remove turbidity without
          removing color has not been found Membrane and glass fiber filters with functional pore
          sizes  of approximately 0 45  u  are convenient  to use Other  techniques such as
          centnfuging and/or filter aids may be used
     Sample Handling and Preservation
     4 1  Since  biological activity  may change  the color  characteristics of a sample,  the
          determination should be made as  soon as possible Refrigeration at 4C is recommended
     Calibration
     5 1  Standard curves must be established (as outlined in Procedure 8 3) for each photometer
          used,  and  are not interchangeable  For color values less than 250, a 5 cm cell path is
          recommended  Less than 5 cm cell paths may be used if calibration is performed with the
          shorter cell
     Apparatus
     6 1  Spectrophotometer or filter photometer capable of transmission measurements using
          tnstimulus filters listed below
Approved for NPDES
Issued 1978
                                        1101-1

-------
       Filter number                    Wavelength of maximum         Corning designation*
                                         transmittance m nm

            1                                    590                       CS 3-107
            2                             ,       540                       CS 4-98
            3                                    438                       CS 5-70

*Available from Corning Glass Works, Optical Products  Department,
Corning, NY 14830

7.    Reagents
      7 1   Standard chloroplatmate solution Dissolve 1 246 g potassium chloroplatmate, K2PtQ6,
           (equivalent to 0 500 g metallic Pt) and 1 g crystalline cobaltous chloride, CoCl26H2O, m
           distilled water containing 100 ml of cone HC1 Dilute to 1000 ml with distilled water
           This standard solution is defined as 500 ADMI color units
      7.2   Sulfunc acid, concentrated
      7.3   Sodium hydroxide, 10 N Dissolve 40 g of sodium hydroxide m 80 ml of distilled water
           Cool to room temperature and dilute to 100 ml with distilled water
8.    Procedure
      8 1   Prepare two 100 ml volumes of sample by maintaining the original pH of one aliquot and
           adjusting the second aliquot as necessary to pH 7 6 with sulfunc acid (7 2) or sodium
           hydroxide (7 3)
      8 2   Filter samples to remove turbidity through a 0 45 u membrane filter, glass fiber filter or
           other suitable media (see interferences 3 1)
      8 3   Use distilled  water  to set the transmittance at  100%  and then  determine the
           transmittance of the  clarified sample  or  standard with each of the three tnstimulus
           filters Calibration standards from 25 to 250 units are recommended
9.    Calculations
      9.1   Calculate  intermediate tnstimulus values  for  samples  and  standards  from the
           transmittance data in 8 3 using the following equations
           Xs = (T3 x 0 1899) + (Tj x 0 791)
           Zs = T3x 11835

           where

           TI = transmittance value in % using filter number 1

           T2 = transmittance value in % using filter number 2
                                          110 1-2

-------
           T3 = transmittance value m % using filter number 3

      9 2   Convert tnstimulus values to the corresponding Munsell values Vx, Vy and Vz by the use
           of published tables2'3'4, or the equation suggested by Bndgeman5
      9 3   Calculate DE values for samples and standards, construct a calibration curve by plotting
           DE against ADMI units of standards and determine ADMI color units of samples from
           the calibration curve
           DE = M [0 23 X (V,, - V,)]2 + [(V, - V,c) - (V~ - V,,)]2 + [04[(V,C - V2C) - (Vys - 

           where Vxs, Vys and Vzs = the Munsell values for Xs, Ys and Zs respectively and Vxc, Vyc
           and Vzc = the Munsell values for a blank solution whose tnstimulus values are Xc, Y0
           andZc
           NOTE 1: If the photometer used is set at 100% transmittance with distilled water, the
           tnstimulus  values for the blank are 9809,  10000 and  11835  for Xc, Yc and Zc
           respectively  If necessary,  tnstimulus values for the blank  are determined  as in
           calculation (9 1)
     9 4   Report ADMI color values at pH 7 6 and at the original pH
           NOTE 2: The intermediate tnstimulus values calculated  under 9 1, using the three
           tnstimulus filters, are used only to calculate the ADMI color value They should not be
           reported as tristimulus values or used to determine dominant wavelength, luminance and
           punty
10   Precision and Accuracy
     101  Accuracy data on actual samples cannot be obtained
     10 2  Precision data are not available at this time

                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition (1975), p 64
2    J Soc Dyers and Colorists, 86, No 8, 354 (1970)
3    Wys/,ecki and Stiles, Color Science, Wiley, N Y, 1967, Tables 6 4 A, B and C
4    Judd and Wyszecki, Color in Business, Science and Industry, 2nd Edition, Wiley, N Y (1963)
     Tables A, B and C m Appendix
5    J Opt Soc Am , Volume 53, page 499, Apnl 1963
6.    Dyes and the Environment-Report on Selected Dyes and Their Effects, Volume 1, Sept 1973
     Appendix, American Dye Manufacturers Institute, Inc
                                         1101-3

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                                         COLOR

                    Method 110.2 (Colorimetric-Platinum-Cobalt)

                                                                       STORET NOS.
                                                                TRUE COLOR 00080
                                                         APPARENT COLOR 00081

      Scope and Application
      1 1  The Platinum-Cobalt  method is useful for measuring color of water derived from
           naturally occurring materials, i e , vegetable residues such as leaves, barks, roots, humus
           and peat materials  The method is not applicable to color measurement on waters
           containing highly colored industrial wastes  See ADMI color method m this manual
           NOTE 1. The Spectrophotometric and Tnstimulus methods are useful for detecting
           specific color problems  The use of these methods, however, is laborious and  unless
           determination of the hue, purity, and luminance is desired, they are of limited value
      Summary of Method
      2 1  Color is measured by visual comparison of the sample with platinum-cobalt standards
           One unit of color is that produced by 1 mg/1 platinum in the form of the chloroplatmate
           ion
      Interferences
      3 1  Since very slight amounts of turbidity interfere with the determination, samples showing
           visible turbidity should be clarified by centnfugation
      3 2  Method is pH dependent
      Sample Handling and Preservation
      4 1   Representative samples shall be taken in scrupulously clean glassware
      42   Since  biological  activity may change  the color  characteristics  of a sample,  the
           determination should be made as soon as possible Refrigeration at 4C is recommended
      Apparatus
      5 1   Nessler tubes  Matched, tall form, 50 ml capacity
      Reagents
      6 1   Standard chloroplatmate solution  Dissolve 1 246 g potassium chloroplatmate, K2PtCl6,
           (equivalent to 0 500 g metallic Pt) and 1 g crystalline cobaltous chloride, CoC12H2O, in
           distilled water containing 100 ml of cone HC1 Dilute to 1000 ml with distilled water
           This standard solution is equivalent to 500 color units
      Preparation of Standards
      7 1   Prepare standards in increments from 5 to 70 units The following series is suggested
Approved for NPDES
Issued 1971
                                         1102-1

-------
                 Ml of Standard Solution
                   Diluted to 500 ml                                 Color in
                   with Distilled Water                           Chloroplatmate Units
                        00                                             0
                        05                                             5
                        10                                            10
                        15                                            15
                        20                                            20
                        25                                            25
                        30                                            30
                        35                                            35
                        40                                            40
                        45                                            45
                        50                                            50
                        60                                            60
                        70                                            70
      7.2   Protect these standards against evaporation and contamination by use of clean, inert
           stoppers
           NOTE 2: The standards also must be protected against the absorption of ammonia since
           an increase in color will result
8.    Procedure
      8 1   Apparent color Observe the color of the sample by filling a matched Nessler tube to the
           50 ml mark with the water and compare with standards  This comparison is made by
           looking vertically downward through the tubes toward a white or specular surface placed
           at such an angle that light is reflected upward through the columns of liquid If turbidity
           has  not been removed by the procedure given m (8 2), report the color as "appaient
           color" If the color exceeds 70 units, dilute the sample with distilled water m known
           proportions until the color is within the range of the standards
      8.2   True color Remove turbidity by centnfuging the sample until the supernatant is clear
           The time required will depend upon the nature of the sample, the speed of the motor, and
           the radius of the centrifuge, but rarely will more than one hour be necessary Compare
           the centnfuged sample with distilled water to insure that turbidity has been removed If
           the sample is clear, then compare with standards as given m (8 1)
9.    Calculation
      9.1   Calculate the color units by means of the following equation


          Color units = A * S0
           where

           A = estimated color of diluted sample
           V = ml sample taken for dilution
                                          1102-2

-------
     9 2   Report the results m whole numbers as follows
                      Color Units                                Record to Nearest

                       1-50                                              1
                     51-100                                              5
                    101-250                                             10
                    251-500                                             20
10   Precision and Accuracy
     101 Precision and accuracy data are not available at this time

                                       Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 64, Method
     204A(1975)
                                         110 2-3

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                                        COLOR

                         Method 110.3  (Spectrophotometric)

                                                                 STORET NO. 00080

      Scope and Application
      1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
           wastes It must be used for industrial wastes that cannot be determined by the Platinum-
           Cobalt method
      Summary of Method
      2 1   Color characteristics are measured at pH 7 6 and at the original pH by obtaining the
           visible absorption  spectrum of the sample on a spectrophotometer  The percent
           transmission at certain selected wavelengths is used to calculate the results
      2 2   The results are expressed in terms of dominant wavelength, hue, luminance, and purity
      Interferences
      3 1   Since very slight amounts of turbidity interfere with the determination, samples must be
           filtered before analysis
      Sample Handling and Preservation
      4 1   Since  biological  activity may change  the  color  characteristics  of a sample,  the
           determination should be made as soon as possible Refrigeration at 4C is recommended
      Reference
      5 1   The procedure to be used for this determination is found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition,
           p 66, Method 204B (1975)
Approved for  NPDES
Issued 1974
                                         1103-1

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                                   CONDUCTANCE

                Method 120.1 (Specific Conductance, umhos at 25Q

                                                                STORET NO. 00095

  1    Scope and Application
      1 1  This method is applicable to drinking, surface, and saline wates, domestic and indus-
           trial wastes and acid rain (atmospheric deposition)
  2    Summary of Method
      2 1  The specific conductance of a sample is measured by use of a self-contained conductivity
           meter, Wheatstone bridge-type, or equivalent
      2 2  Samples are  preferable analyzed at 25C If not, temprature corrections aremade and
           results reported at 25C
  3    Comments
      3 1  Instrument must be standardized with KC1 solution before daily use
      3 2  Conductivity cell must be kept clean
      3 3  Field measurements with comparable instruments are reliable
      3 4  Temperature variations and corrections represent the largest source of potential error
  4    Sample Handling and Preservation
      4 1  Analyses can be performed either in the field or laboratory
      42  If analysis is not completed  within 24 hours of sample collection, sample should be
           filtered through a 0 45 micron filter and stored at 4C Filter and apparatus must be
           washed with  high quality distilled water and pre-rmsed with sample before use
  5    Apparatus
      5 1  Conductivity bridge, range 1 to 1000 jumho per centimeter
      5 2  Conductivity cell, cell constant 1 0 or micro dipping type cell with 1 0 constant YSI
           #3403 or equivalent
      5 4  Thermometer
  6    Reagents
      6 1   Standard potassium chloride solutions, 0 01 M Dissolve 0 7456 gm of pre-dried (2 hour
           at 105C) KC1 in distilled water and dilute to 1 liter at 25C
  7    Cell Calibration
      7 1   The analyst should use the standard potassium chloride solution (6 1) and the table
           below to check the accuracy of the cell constant and conductivity bridge
Approved for NPDES
Issued 1971
Editorial revision, 1982
                                         120 1-1

-------
             Conductivity 0 01 m KC1

                       C
                                                   Micromhos/cm
10.
                        21
                        22
                        23
                        24
                        25
                        26
                        27
                        28
                                                         1305
                                                         1332
                                                         1359
                                                         1386
                                                         1413
                                                         1441
                                                         1468
                                                         1496
Procedure
8.1  Follow the direction of the manufacturer for the operation of the instrument
8 2  Allow samples to come to room temperature (23 to 27C), if possible
8.3  Determine the temperature of samples within 0 5C If the temperature of the samples
     is not 25C, make temperature correction in accordance with the instruction in Section
     9 to convert reading to 25
Calculation
9 1  These temperature corrections are based on the standard KC1 solution
     9.1 1   If the temperature of the sample is below 25C, add 2% of the reading per degree
     912   If the temperature is above 25C, subtract 2% of the reading per degree
9.2  Report results as Specific Conductance, //mhos/cm at 25
Precision and Accuracy
10.1  Forty-one analysts in 17 laboratories analyzed six  synthetic water samples containing
      increments of inorganic salts, with the following results
       Increment as
   Specific Conductance
           100
           106
           808
           848
           1640
           1710
                         Precision as
                      Standard Deviation
                              755
                              814
                             661
                             796
                             106
                             119
 (FWPCA Method Study 1, Mineral and Physical Analyses )
Bias,
-202
-076
-363
-454
-536
-508
         Accuracy as
  Bias,
omhos/cm

  -20
  -08
  -293
  -385
  -879
  -869
    10 2 In a  single  laboratory  (EMSL) using  surface  water samples  with an  average
         conductivity of 536 //mhos/cm at 25C, the standard deviation was 6
                                         120 1-2

-------
                                  Bibliography
1    The procedure to be used for this determination is found in
     Annual Book of ASTM Standards Part 31, "Water," Standard Dl 125-64, p  120 (1976)
2    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 71,
     Method 205 (1975)
3    Instruction Manual for YSI Model 31 Conductivity Bridge
4    Peden, M  E , and Skowron "Ionic Stability of Precipitation Samples,"  Atmospheric
     Environment, Vol 12, p 2343-2344, 1978
                                      120 1-3

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                      HARDNESS, Total (mg/1 as CaCO3)

                 Method 130.1 (Colorimetric, Automated EDTA)

                                                              STORET NO. 00900

     Scope and Application
     1 1  This automated method is applicable to drinking, surface, and saline waters The
          applicable range is 10 to 400 mg/1 as CaCO3 Approximately 12 samples per hour can be
          analyzed
     Summary of Method
     2 1  The magnesium EDTA exchanges magnesium on an equivalent basis for any calcium
          and/or other cations to form a more stable EDTA chelate than magnesium The free
          magnesium reacts with calmagite at a pH of 10 to give a red-violet complex Thus, by
          measuring only magnesium concentration in the final reaction stream, an accurate
          measurement of total hardness is possible
     Sample Handling and Preservation
     3 1  Cool to 4C, HNO3 to pH < 2
     Interferences
     4 1  No significant interferences
     Apparatus
     5 1  Techmcon AutoAnalyzer consisting of
          511 Sampler I
          5 12 Continuous Filter
          5 1 3 Manifold
          514 Proportioning Pump
          515 Colorimeter equipped with 15 mm tubular flow cell and 520 nm filters
          516 Recorder equipped with range expander
     Reagents
     6 1  Buffer  Dissolve 67 6 g NH4C1 in 572 ml of NH4OH and dilute to 1 liter with distilled
          water
     6 2  Calmagite Indicator  Dissolve 0  25  g m  500 ml  of distilled  water  by stirring
          approximately 30 minutes on a magnetic stirrer Filter
     6 3  Monomagnesium ethylenediamme-tetraacetate (MgEDTA)  Dissolve 0 2 g of MgEDTA
          in 1 liter of distilled water
     6 4  Stock Solution Weigh 1 000 g of calcium carbonate (pre-dned at 105C) into 500 ml
          Erlenmeyer flask, add 1  1 HC1 until all CaCO3 has dissolved Add 200 ml of distilled
          water and boil  for a few minutes Cool, add a few drops of methyl red indicator, and
          adjust to the orange color with 3N NH4OH and dilute to 1000 ml with distilled water 1 0
          ml=10mgCaCO3
Approved for NPDES
Issued  1971

                                        130 1-1

-------
           641 Dilute each of the following volumes of stock solutions to 250 ml in a volumetric
                flask for appropriate standards

                   Stock Solution, ml                                CaCO3,  mg/1

                       25                              '            100
                       50                                          200
                       10 0                                          40 0
                       150                                          60 0
                       25 0                                         100 0
                       35 0                                         140 0
                       50 0                                         200 0
                       75 0                                         300 0
                     100 0                                         400 0

     6 5   Ammonium Hydroxide, IN Dilute 70 ml of cone NH4OH to 1 later with distilled water

7.    Procedure
     71   Pretreatment
           711 For drinking waters, surface waters, saline waters, and dilutions thereof, no
                pretreatment steps are necessary Proceed to 7 2
           712 For most wastewaters, and highly polluted waters, the sample must be digested as
                given in the Atomic Absorption Methods section of this manual, paragraphs 413
                and 414 Following this digestion, proceed to 7 2
     7 2   Neutralize 50 0 ml of sample with  IN ammonium hydroxide (6 5) and note volume of
           NH4OHused
     7 3   Set up manifold as shown  in Figure 1
     7 4   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
           reagents, feeding distilled water through the sample line  Adjust  dark current and
           operative opening on colorimeter to obtain stable baseline
     7 5   Place distilled water wash tubes in alternate openings in Sampler and set sample timing
           at 2 5 minutes
     7 6   Arrange working standards in Sampler in order of decreasing concentrations Complete
           loading of Sampler tray with unknown samples
     7.7   Switch sample line from distilled water to Sampler and begin analysis
8.    Calculation
     8 1   Prepare standard cun'e  by plotting  peak  heights of  processed standards against
           concentration values  Compute concentration of samples by comparing sample peak
           heights with standard curve Correct for amount of NH4OH used in 7 2 as follows

           mg/1 = ^x B

           where;

           A= Vol of sample plus volume of NH4OH
           B = Concentration from standard curve
                                          130 1-2

-------
9    Precision and Accuracy
     91  In a single laboratory (EMSL), using surface water samples at concentrations of 19, 120,
          385, and 366 mg/1 as CaCO3, the standard deviations were 15, 15, 4 5, and  50,
          respectively
     92  In a single laboratory (EMSL), using surface water samples at concentrations of 39 and
          296 mg/1 as CaCO3, recoveries were 89% and 93%, respectively

                                     Bibliography

1    Techmcon AutoAnalyzer Methodology, Bulletin No 2/Techmcon Controls, Inc , Chauncey,
     New York (July 1960)
2    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 202,
     Method 309B (1975)
                                        130 1-3

-------
                      8-    =
                   ( o
                   vlx
CO C9
                                           LU
                                           1
                                           CO
                                           in
                                                                        CO
                                                                        CO
                                        at x =
                                        <  C3
                                        _i X cj>
                                         00000000

                                                                        CD
                                  130 1-4

-------
                      HARDNESS,  Total (mg/1  as CaCO3)
                        Method 130.2  (Titrimetric,  EDTA)

                                                              STORET NO.  00900
     Scope and Application
     1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
          wastes
     1 2   The method is  suitable for all concentration ranges of hardness, however, in order to
          avoid large titration volumes, use a sample aliquot containing not more than 25 mg
          CaCO3
     1 3   Automated titration may be used
     Summary of Method
     2 1   Calcium and magnesium ions in the sample are sequestered upon the addition of
          disodium ethylenediamme tetraacetate (Na2EDTA) The end point of the reaction is
          detected by means  of Enochrome Black T indicator, which has a red color in the
          presence of calcium and magnesium and a blue color when the cations are sequestered
     Sample Handling and Preservation
     3 1   Cool to 4C, HNO3 to pH < 2
     Comments
     4 1   Excessive  amounts of heavy  metals can  interfere  This is  usually overcome by
          complexing the metals with cyanide
          411 Routine addition of sodium cyanide solution (Caution deadly poison) to prevent
               potential metallic interference is recommended
     Apparatus
     5 1   Standard laboratory titnmetnc equipment
     Reagents
     6.1   Buffer solution
          6 1 1 If magnesium EDTA is available  Dissolve,  16 9 g NH4C1  in  143  ml cone
               NH4OH in a 250 ml volumetric, add 1 25 g of magnesium salt of EDTA and dilute
               to the mark with distilled water Then go to 6  1 3
          612 If magnesium EDTA is unavailable Dissolve 1 179  g disodium EDTA (analytical
               reagent grade) and 780 mg MgSO47H2O (or 644 mg MgCl26H2O) in 50 ml
               distilled water Add this solution to a 250 ml volumetric flask containing 16 9 g
               NH4C1 and 143  ml cone  NH4OH with mixing  and dilute to the mark with
               distilled water
          613 Store in a tightly stoppered plastic bottle, stable for approximately one month
               Dispense  with bulb operated pipet Discard when 1 or 2 ml added to sample fails to
               produce a pH of 10 0 01 at end point of titration
Approved for NPDES
Issued  1971
Editorial revision 1978 and 1982

                                       130 2-1

-------
     614 Commercially available "odorless buffers" which are more stable, may be used
6.2  Inhibitors For most waters inhibitors are not necessary If interfering ions are present
     use one of the following
     621 Inhibitor I NaCN powder (Caution extremely poisonous)  Flush solutions or
          sample containing this down dram using large quantities of water Make sure no
          acids are present which might liberate HCN gas
     6.2 2 Inhibitor II Dissolve 5 0 g Na2S-9 H2O or 3 7 g Na2S5 H2O in 100 ml distilled
          water  Exclude air with tightly fitted rubber stopper This gives sulfide precipitates
          which may obscure the end point if large quantities of heavy metals are present
          Deteriorates rapidly through air oxidation
     623 Inhibitor III Dissolve 4 5 g hydroxylamme hydrochlonde in 100 ml of 95%
          ethanol or isopropanol
6 3  Indicator  Use a  commercially available indicator  such as Calmagite indicator
     (Malhnckrodt) or one of the formulations descnbed below (6 3 1-6 3 3)
     6.3 1 Mix 0 5 g Enochrome Black T with 4 5 g hydroxylamme hydrochlonde Dissolve
          in 100 ml of 95% ethanol or isopropanol
     632 Dissolve 0 5  to  1 0 g Enochrome Black T in an appropnate solvent such as
          tnethanolamme or 2-methoxyethanol Stable approximately one week
     633 Mix together 0 5 g Enochrome Black T and 100 g NaCl
64  Standard EDTA titrant, 0 02 N 'Place 3 723 g analytical reagent grade disodium
     ethylenediamme tetraacetate dihydrate, Na2H2C10H12O8N22 H2O in a 1 liter volumetric
     flask and dilute to the mark with distilled water Check with standard calcium solution
     (6 4 1) by titration  (6 4 5) Store  in polyethylene Check penodically because of gradual
     detenoration
     64.1 Standard calcium solution 0 02 N Place 1 000 g anhydrous calcium carbonate
          (primary standard low in metals) in a 500 ml flask Add, a little at a time, 1 +1
          HCL (6 4 2) until all of the CaCO3 has dissolved Add 200 ml distilled water
          Boil for a few minutes to expel  COa Cool Add a few drops of methyl red
          indicator (6 4 3) and adjust to  intermediate orange color by adding 3N
          NH4OH (6 4 4) or 1 + 1 HC1 (6 4 2) as required Quantitatively transfer to a
          1 liter volumetric flask and dilute to mark with distilled water
     642 Hydrochlonc acid solution, 1 + 1
     643 Methyl red indicator Dissolve 0 10 g methyl red in distilled water in a 100 ml
          volumetric flask and dilute to the mark
     644 Ammonium hydroxide solution, 3 N  Dilute 210 ml of cone NH4OH to 1 liter with
          distilled water
     645 Standardization titration procedure Place 10 0 ml standard calcium solution
          (6 4 1) in vessel containing about 50 ml distilled water Add 1ml buffer solution
          (6 1) Add 1-2 drops indicator (6 3) or small scoop of dry indicator (6 3 3) Titrate
          slowly with continuous stirnng until the last reddisl^ tinge disappears, adding last
                                    130 2-2

-------
           few drops at 3-5 second intervals  At end point the color is blue Total titration
           duration should be 5 minutes from the time of buffer addition
           N of EDTA    =
                                .  f.~A
                              ml of EDTA
6 5   Ammonium Hydroxide, IN  Dilute 70 ml of cone NH4OHto 1 liter with distilled water
Procedure
7 1   Pretreatment
      711  For drinking waters,  surface waters,  saline waters, and dilutions thereof,  no
           pretreatment steps are necessary Proceed to 7 2
      712  For most wastewaters, and highly polluted waters, the sample must be digested as
           given in the Atomic Absorption Methods section of this manual, paragraphs 413
           and 414 Following this digestion, proceed to 7 2
7 2   Titration of sample-normal to high hardness
      721  Sample should require <15 ml  EDTA  titrant  (64)  and titration should be
           completed within 5 minutes of buffer addition
      722  Place 25 0 ml sample in titration vessels, neutralize with IN ammonium hydroxide
           (6 5) and dilute to about 50 ml
      723  Add 1 to 2 ml buffer solution (6 1)
      724  If end point is not sharp (as determined by practice run) add inhibitor at this point
           (see 7 4)
      725  Add 1 to 2 drops indicator solution (63 1 or 6 3 2) or small scoop of dried powder
           indicator formulation (6 3 3)
      726  Titrate slowly with continuous stirring with standard EDTA titrant (6 4) until last
           reddish tint disappears  Solution is normally blue at end point
7 3   Titration of sample-low hardness (less than 5 mg/1)
      731  Use a larger sample (100 ml)
      732  Use proportionately larger amounts of buffer, inhibitor and indicator
      733  Use a microburet and run a blank using redistilled, distilled or deiomzed water
7 4   To correct for interferences
      741  Some metal ions  interfere by causing  fading or indistinct end points  Inhibitors
           reduce this in accord with the scheme below for 25 0 ml samples diluted to 50 ml
                                    130 2-3

-------
Interfering
Substance
Maximum  Concentrations of Interferences Permissible
             with Various Inhibitors8

               Maximum Interference
                Concentration mg/1

Aluminum
Barium
Cadmium
Cobalt
Copper
Iron
Lead
Manganese (Mn2+)
Nickel
Strontium
Zinc
Polyphosphate
Inhibitor I
20
b
b
over 20
over 30
over 30
b
b
over 20
b
b

a Based on 25-ml sample diluted to 50
b Titrates as hardness
c Inhibitor fails if substance is present
Inhibitor II
20
b
20
03
20
5
20
1
03
b
200
10
ml
Inhibitor III
20
b
b
DC
03
20
b
1
Oc
b
b


          742 Inhibitor I At step 7 2 4 add 250 mg NaCN  Add sufficient buffer to achieve pH
               10 0  0 1 to offset alkalinity resulting from hydrolysis of sodium cyanide
          7.4 3 Inhibitor II At step 7 2 4 add 1 ml of inhibitor II (6 2 2)
          744 Inhibitor III At step 7 2 4 add 1 ml of inhibitor III (6 2 3)
     Calculations

  Hardness (EDTA) pi   A x N x 50,000
     mg CaCO3/!   g     ml sample

               where
               A = ml EDTA titrant (6 4)
               N = normality of EDTA titrant
                                         1302-4

-------
      Precision and Accuracy
      9 1   Forty-three analysts in nineteen  laboratories analyzed six synthetic  water  samples
           containing exact increments of calcium and magnesium salts, with the following results
      Increment as
     Total Hardness
     mg/liter, CaCO3
   Precision as
Standard Deviation
mg/hter, CaCO3
          Accuracy as
 Bias,                  Bias,
  %             mg/hter, CaCO3
            31
            33
           182
           194
           417
           444
      287
      252
      487
      298
      965
      973
-087
-073
-019
-104
-335
-323
 -0003
 -024
 -04
 -20
-130
-143
(FWPCA Method Study 1, Mineral and Physical Analyses)
     92   In a single laboratory (EMSL), using surface water samples at an average concentration
           of 194 mg CaCO3/1, the standard deviation was   3
     93   A synthetic unknown sample containing 610 mg/1 total hardness as CaCO3 contributed
           by 108 mg/1 Ca and 82 mg/1 Mg, and the following supplementary substances 3 1 mg/1
           K, 19 9 mg/1 Na, 241 mg/1 chloride, 0 25 mg/1 nitrite N, 1 1 mg/1 nitrate N, 259 mg/1
           sulfate, and 42 5 mg/1 total alkalinity (contributed by NaHCO3)  in distilled water was
           analyzed m 56 laboratories by the EDTA titnmetnc method with a relative standard
           deviation of 2 9% and a relative error of 0 8%


                                     Bibliography


1    Standard Methods for the Examination of Water and Wastewater,  14th Edition, p 202,
     Method 309B (1975)   '
2    Annual Book of ASTM Standards, Part 31, "Water", Standard D 1126-67, p 161, Method B
     (1976)
                                         130 2-5

-------
                                         ODOR

                Method 140.1 (Threshold  Odor, Consistent  Series)

                                                          STORET  NO.  60C: 00086
                                                                   Room Temp: 00085

      Scope and Application
      1 1   This method is applicable to the determination of threshold odor of drinking, surface,
           and saline waters, domestic and industrial wastes
      1 2   Highly odorous samples are reduced in concentration proportionately before being
           tested Thus, the method is applicable to samples ranging from nearly odorless natural
           waters to industrial wastes with threshold odor numbers in the thousands
      Summary of Method"'
      2 1   The sample of water is diluted with odor-free water until a dilution that is of the least
           definitely perceptible odor to each  tester is found  The resulting ratio by which  the
           sample has been diluted is called the "threshold odor number" (TON)
      2 2   People vary widely as to odor sensitivity, and even the same person will not be consistent
           in the concentrations they can detect from day to day Therefore, panels of not less than
           five persons, and preferably 10 or more, are recommended to overcome the variability of
           using one observer m As an absolute minimum, two persons are necessary One to make
           the sample dilutions and one to determine the threshold odor
      Sample Handling and Preservation
      3 1   Water samples must be collected m glass bottles with glass or Teflon-lined  closures
           Plastic containers are not reliable for odor samples and must not be used
      3 2   Odor tests should be completed  as soon as possible after  collection of the sample  If
           storage is necessary, collect at least 1000 ml of sample in a bottle filled  to the top
           Refrigerate, making sure no extraneous odors can be drawn into the sample as the water
           cools
      Interferences
      4 1   Most tap waters and some waste waters are chlorinated It is often desirable to determine
           the odor of the chlorinated sample as well as of the same sample after  removal  of
           chlorine Dechlormation is achieved using sodium thiosulfate in exact  stoichiometnc
           quantity
           411 It is important to check a blank to which a similar amount of dechlonnating agent
                has been added to determine if any odor has been imparted  Such odor usually
                disappears upon standing if excess reagent has not been added
      Apparatus
      5 1   Odor-free glassware  Glassware must be freshly  cleaned shortly before use, with non-
           odorous soap and acid cleaning solution followed by rinsing with odor-free water (6 1)
Issued 1971

                                         140 1-1

-------
           Glassware used in odor testing should be reserved for that purpose only Rubber, cork,
           and plastic stoppers must not be used
     5 2   Constant temperature bath  A water bath or electric hotplate capable of maintaining a
           temperature control of  1C for performing the odor test at 60C The temperature bath
           must not contribute any odor to the odor flasks
     5 3   Odor flasks Glass stoppered 500 ml (1)32) Erlenmeyer flasks, or wide-mouthed 500 ml
           Erlenmeyer flasks equipped with Petn dishes a$ cover plates
           NOTE: Narrow-mouth vessels are not suitable for running odor tests Potential positive
           bias due to color and/or turbidity of water sample under observation can be eliminated
           by wrapping odor flasks in aluminum foil, painting flasks with non-odorous paint, or by
           using red actinic Erlenmeyer flasks
     5 4   Sample bottles Glass bottles with glass or Teflon-lined closures
     5.5   Pipets, measuring 10 0 and 1 0 ml graduated in tenths
     5.6   Graduated cylinders 250,200,100, 50, and 25 ml
     5 7   Thermometer 0-110C ( 1C), chemical or metal stem dial type
     5.8   Odor-free water generator See Figure 1
6.   Reagents
     6 1   Odor-free water  Odor-free dilution water must  be prepared as needed by filtration
           through a bed of activated carbon Most tap waters are suitable for preparation of odor-
           free waters, except that it is necessary to check the filtered water for chlorine residual,
           unusual salt concentrations, or unusually high or low pH  All these may affect some
           odorous samples
           Where supplies are adequate, distilled water avoids these problems as a source of odor-
           free water A convenient odor-free water generator may be made as shown in Figure  1
           Pass tap or distilled water through the  odor-free water generator at a rate of 0 1
           liter/minute When the generator is first started, it should be flushed to remove carbon
           fines before the odor-free water is used
           611 The quality of water obtained from the odor-free water generator should be
                checked daily  at the temperature tests are  to be conducted  (room temperature
                and/or 60C)  The life of the carbon will vary with the condition and amount  of
                water filtered  Subtle odors of biological origin are often found if moist carbon
                filters are permitted to stand idle between test periods Detection of odor in the
                water coming through the carbon indicates a change of carbon is needed
7    Procedure
     7 1   Precaution  Selection of persons to make odor tests should be carefully made Extreme
           sensitivity is not required, but insensitive persons should not be used A good observer
           has a sincere interest in the test Extraneous odor stimuli such as those caused by
           smoking and eating prior to the test or through the use of scented soaps, perfumes, and
           shaving lotions must be avoided  The tester should be free from colds or allergies that
           affect odor-response Frequent rests in an odor-free atmosphere are recommended  The
           room in which the tests are to be conducted should be free from distractions, drafts, and
           other odor  In certain industrial atmospheres, a special odor-free room may be required,
           ventilated by  air filtered through  activated carbon and  maintained at a constant
                                          140 1-2

-------
      comfortable temperature and humidity For precise work a panel of five or more testers
      should be used The persons making the odor measurements should not prepare the
      samples and should not know the dilution concentrations being evaluated These persons
      should have been made familiar with the procedure before participating in a panel test
      Always start.with the most dilute sample to avoid tiring the senses with the concentrated
      sample The temperature of the samples during testing should be kept within 1 degree of
      the specified temperature for the test
 7 2   Threshold measurement  The ratio by which the odor-bearing sample has to be diluted
      with odor-free water for the odor to be just detectable by the odor test is the "threshold
      odor number" (TON)  The total volume of sample and odor-free water used in each
      test is 200 ml  The proper volume of odor-free water is put into the flask first, the sample
      is then added to the water  Table 1 gives the dilutions and corresponding threshold
      numbers

                                      Table 1

                               Threshold  Odor Number
                           Corresponding to Various Dilutions

             Sample Volume (ml)                              Threshold Odor
              Diluted to  200 ml                                 Number
                  200                                             1
                  100                                             2
                   50                                             4
                   25                                             8
                  125                                            16
                  63                                            32
                  31                                            64
                  16                                           128
                  08                                           256


7 3  Determine the approximate range of the threshold odor by
     7 3 1 Adding 200 ml, 50 ml, 12 5 ml, and 3 1 ml of the sample to separate 500 ml glass-
          stoppered Erlenmeyer flasks containing odor-free water to make a total volume of
          200 ml A separate flask containing only odor-free water serves as the reference for
          comparison If run at 60'C, heat the dilutions and the reference in the constant
          temperature bath at 60C ( 1C)
     732 Shake the flask containing the odor-free water, remove the stopper, and sniff the
          vapors Test the sample containing the least amount of odor-bearing water m the
          same way  If odor can be detected in this dilution, more dilute samples must be
          prepared as described in (7 3 3) If odor cannot be detected in the first dilution,
          repeat the above procedure using the  sample  containing  the next  higher
          concentration of the  odor-bearing watei, and continue this process until odor is
          clearly detected
                                    140 1-3

-------
          2 HOLE
        RUBBER STOPPER
            WtitfM
            r&'iWj&
                         % ,,
                          **
 '*
 "w
GRANULAR
4 x 10-MESH

ACTIVATED
 CARBON
                         PEA SIZE
                         GRAVEL
FIGURE 1. ODOR-FREE WATER GENERATOR
               140 1-4

-------
      7 3 3 If the sample being tested requires more extensive dilution than is provided by
           Table 1, an intermediate dilution is prepared from 20 ml of sample diluted to 200
           ml with odor-free water  Use this dilution for  the  threshold determination
           Multiply the T O N  obtained by ten to correct for the intermediate dilution In
           rare cases more than one tenfold intermediate dilution step may be required
7 4   Based on the results obtained in the preliminary test, prepare a set  of dilutions using
      Table 2 as a guide One or more blanks aie inserted in the  series, in  the vicinity of the
      expected threshold, but avoiding any repeated pattern  The observer does not  know
      which dilutions are odorous and which are blanks He smells each  flask in sequence,
      beginning with the least concentrated sample and comparing with a known flask of odor-
      free water, until odor is detected with utmost certainty

                                         Table 2
                            Dilutions  for Various Odor Intensities
                         Sample Volume m Which Odor First Noted
                     200 ml	50 ml     12 5 ml   3 1 ml

                  Volume (ml)  of Sample to be Diluted to 200 ml

                     200         100        50      (intermediate
                      100          50        25      Dilution
                       50          25        12 5    See 7 3 3)
                       25          12 5       63
                       125          63       31

7 5  Record the observations of each tester by indicating whether odor is noted (+ sign) in
     each test flask
  For example

  ml sample
  diluted to 200 ml         12 5      0      25       0      50      100     200

  Response                  -       -      +       -      +      +      +

Calculations
8 1    The threshold odor number is the dilution ratio at which odor is just detectable  In the
      example above (7 5), the first detectable odor occurred when 25 ml sample was diluted to
      200 ml Thus, the threshold is 200 divided by 25, equals 8 Table 1 lists the threshold odor
      numbers that correspond to common dilutions
8 2    Anomalous responses sometimes occur, a low concentration may be called positive and a
      higher concentration in the senes may be called negative In such a case, the threshold is
      designated as that point of detection after which no further anomalies occur
                                     140 1-5

-------
        For instance
        ml sample
        diluted to 200 ml
      63
125
0
25
50
100
        Response                 +--       +      +      +
        threshold                                         I
                                                    Threshold
     8 3   Calculations of panel results to find the most probable average threshold are best
           accomplished by appropriate statistical methods For most purposes, the threshold of a
           group can  be expressed as the geometric mean of the individual thresholds  The
           geometric mean is calculated in the following manner
           831 Obtain odor response as outlined m Procedure and record results
                For example
ml of Odor-
free water
                                          Table 3
                                    Sample Odor Series
 ml of
 Sample
       Observer Response*
              3
    188
    175
    200
    150
    200
    100
      0
 125
 25
  0
 50
  0
100
200
*Circled plus equals threshold level

           832 Obtain individual threshold odor numbers from Table 1


                        Observer

                          1
                          2
                          3
                          4
                          5
                                            TON

                                               4
                                               8
                                               2
                                               2
                                               8
           8.3 3 The geometric mean is equal  to  the  nth root of the  product of n numbers
                Therefore
             4x8x2x2x8 = 1,024
             and tf 1,024 = log 1,024 = 30103 = 0 6021
                             5         5
             and anti-log of 0 6021 = 4 = T O N
                                           140 1-6

-------
9    Precision and Accuracy
     9 1   Precision and accuracy data are not available at this time
     92   A threshold number is not a precise value In the case of the single observer, it represents
           a judgment at the time of testing Panel results are more meaningful because individual
           differences have less influence on the result One or two observers can develop useful data
           if comparison with larger panels has been made to check their sensitivity  Comparisons
           of  data from time to time or place to place should not  be attempted unless all test
           conditions have been carefully standardized and some basis for comparison of observer
           intensities exists

                                       Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 75, Method
     206, (1975)
2    ASTM, Comm E-18, STP 433, "Basic Principles of Sensory Evaluation", STP 434, Manual on
     Sensory Testing Methods, STP 440, "Correlation of Subjective-Objective Methods in the Study
     of Odors and Taste", Phil, Pennsylvania (1968)
3    Baker, R A, "Critical Evaluation of Olfactory Measurement" Jour WPCF, 34, 582 (1962)
                                          140 1-7

-------
                                          pH

                            Method 150.1 (Electrometric)

                                                                       STORET NO.
                                                          Determined on site   00400
                                                                   Laboratory   00403

1    Scope and Application
     1 1  This method is applicable to drinking, surface, and saline waters, domestic and industrial
          wastes and acid rain (atmospheric deposition)
2    Summary of Method
     2 1  The pH of a sample is determined electrometncally using either  a glass electrode in
          combination with a reference potential or a combination electrode
3    Sample Handling and Preservation
     3 1  Samples should be analyzed as soon as possible preferably in the  field at the time of
          sampling
     3 2  High-purity waters and waters not at equilibrium with the atmosphere are subject to
          changes when exposed to the atmosphere, therefore the sample containers should be
          filled completely and kept sealed prior to analysis
4    Interferences
     4 1  The glass electrode,  in general,  is not subject to solution interferences from color,
          turbidity, colloidal matter, oxidants, reductants or high salinity
     4 2  Sodium error at pH levels greater than  10 can be reduced or eliminated by using a "low
          sodium error" electrode
     4 3  Coatings of oily material or particulate matter can impair electrode response  These
          coatings can usually be removed by gentle wiping or detergent washing, followed by
          distilled water rinsing  An additional treatment with hydrochloric acid (1 + 9) may be
          necessary to remove any remaining film
     4 4  Temperature effects on the electrometnc measurement of pH arise from  two sources
          The first is  caused by the  change in electrode output at  various  temperatures This
          interference can be controlled with instruments having temperature  compensation or by
          calibrating the  electrode-instrument system at  the temperature of the samples The
          second source is the change of pH inherent in the sample at various temperatures This
          error is sample dependent and cannot be controlled, it should therefore be noted by
          reporting both the pH and temperature at the time of analysis
5    Apparatus
     51  pH Meter-laboratory or field model A wide variety of instruments are commercially
          available with vanous specifications and optional equipment
                       >

Approved for  NPDES
Issued  1971
Editorial revision 1978 and 1982

                                         150 1-1

-------
     5 2   Glass electrode
     5 3   Reference electrode-a calomel, silver-silver chloride or other reference electrode of
           constant potential may be used
           NOTE 1:  Combination electrodes  incorporating  both measuring and  reference
           functions are convenient to use and are available with solid, gel type filling materials that
           require minimal maintenance
     5 4   Magnetic stirrer and Teflon-coated stirring bar
     5 5   Thermometer or temperature sensor for automatic compensation
6    Reagents
     6 1   Primary standard buffer salts are available from the National Bureau of Standards and
           should be used in situations where extreme accuracy is necessary
           6.1 1 Preparation of reference solutions from these salts require some special precautions
                and handling0' such as low conductivity dilution water, drying ovens, and carbon
                dioxide free purge gas These solutions should be replaced at least once each
                month
     6 2   Secondary standard buffers may be prepared from NBS salts or purchased as a solution
           from commercial vendors Use of these commercially available solutions, that have been
           validated by comparison to NBS standards, are recommended for routine use,
7.   Calibration
     7.1   Because of the wide variety of pH meters and accessories, detailed operating procedures
           cannot be incorporated into this  method  Each analyst must be acquainted with the
           operation of each system and familiar with all instrument functions Special attention to
           care of the electrodes is recommended
     7 2   Each instrument/electrode system must be calibrated at a minimum of two points that
           bracket the expected pH of the samples and are approximately three pH units or more
           apart
           721 Various instrument designs may involve use of a "balance" or "standardize" dial
                and/or a slope adjustment as outlined in the manufacturer's instructions  Repeat
                adjustments on successive portions of the two buffer solutions as outlined in
                procedure 8 2 until readings are  within 0 05 pH units of the buffer solution value
8    Procedure
     8 1   Standardize the meter and electrode system as outlined in Section 7
     8.2   Place the sample or buffer solution in a clean glass beaker using a sufficient volume to
           cover  the sensing elements of the electrodes and  to give adequate clearance for the
           magnetic stirring bar
           821 If field measurements are being made the electrodes may be immersed directly in
                the sample stream to an adequate depth and moved in a manner to insure sufficient
                sample movement across the electrode sensing element as indicated by drift free
                ( < 0 1 pH) readings
     83   If the sample temperature differs by more than 2C from the buffer solution the measured
           pH values  must be corrected  Instruments are equipped with automatic or  manual
                  '"National Bureau of Standards Special Publication 260

                                          150 1-2

-------
10
      compensators  that  electronically  adjust  for  temperature  differences  Refer  to
      manufacturer's instructions
 8 4   After rinsing and gently wiping the electrodes, if necessary, immerse them  into the
      sample beaker or sample stream and stir at a constant rate to provide homogeneity and
      suspension of solids Rate of stirring should minimize the air transfer rate at the air water
      interface  of the sample  Note and record  sample pH and temperature   Repeat
      measurement on successive volumes of sample until values differ by less than 0 1 pH
      units Two or three volume changes are usually sufficient
 8 5   For acid rain samples it is most important that  the magnetic stirrer is not used
      Instead, swirl  the sample gently for a  few  seconds after the introduction of the
      electrode(s)  Allow the electrode(s) to equilibrate  The air-water interface should
      not be disturbed while  measurement  is being  made  If the sample is  not  in
      equilibrium  with  the  atmosphere,  pH  values  will  change  as the
      dissolved gases are either absorbed or  desorbed  Record  sample pH and
      temperature
 Calculation
 9 1   pH meters read directly in pH units Report pH to the nearest 0 1 unit and temperature
      to the nearest C
 Precision and Accuracy
 10 1  Forty-four analysts  in  twenty laboratories analyzed six synthetic water  samples
      containing exact increments of hydrogen-hydroxyl ions, with the following results
        pH Units
           35
           35
           71
           72
           80
           80
                     Standard Deviation
                         pH Units

                            010
                            Oil
                            020
                            018
                            013
                            012
(FWPCA Method Study 1,  Mineral and Physical Analyses)
 Bias,
  %
                                                                 Accuracy as
 -029
 -000
+ 101
 -003
 -012
+016
  Bias,
pH  Units

  -001

  +007
  -0002
  -001
  +001
     102 In a single laboratory (EMSL), using surface water samples at an average pH of 7 7, the
          standard deviation was  0 1
1
2
                                 Bibliography

Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 460, (1975)
Annual Book of ASTM Standards, Part 31, "Water", Standard D1293-65, p 178 (1976)
Peden, M  E  and Skowron, L M ,  Ionic  Stability of  Precipitation Samples,
Atmospheric Environment, Vol 12, pp 2343-2349, 1978
                                         150 1-3

-------
 United States
 Environmental Protection
 Agency
 Environmental Monitoring and
 Support Laboratory
 Cincinnati OH 45268
 Research and Development

 pH,  Continuous  Monitoring
 (Electrometric)Method  150.2
 1    Scope and Application

 1 1  This method is applicable to the
 continuous pH measurement of
 drinking surface, and saline waters
 domestic and industrial waste waters

 2    Summary  of Method

 2 1  The pH of a sample is determined
 electrometncally using a glass
 electrode with a reference electrode
 or a single combination electrode

 3    Sample Handling and
 Preservation

 3 1  The composition of the water  or
 waste contacting the measuring
 electrode system must be
 representative of the total flow from
 the water body
4   Interferences
4 1  The glass electrode  in general,
is not subject to solution interferences
from color  turbidity colloidal matter
oxidants reductants or high salinity

4 2  Sodium error at pH levels
greater than 10 can be reduced or
eliminated by using a  low sodium
error  electrode

4 3  Manually inspect the conditions
of the electrodes every 30 days for
coating by oily materials or buildup of
lime  If oil and grease and/or scale
buildup are not present, this time
interval may be extended

431  Coatings of oil, grease and
very fine solids can impair electrode
response These can usually be
removed by gentle wiping and
 detergent washing The use of flow-
 through electrode housings which
 provide higher flow velocity helps to
 prevent the coating action

 432  Heavy paniculate matter such
 as lime accumulation can be removed
 by careful scrubbing or immersion in
 dilute (1+9) hydrochloric acid
 Continuous monitoring under these
 conditions benefits from ultrasonic or
 other m-lme continuous cleaning
 methods

 4 4  Temperature effects on the
 eJectrometric measurement of pH
 arise from two sources The first is
 caused by the change m electrode
 output at various temperatures  This
 interference can be controlled with
 instruments having temperature
 compensation or by calibrating the
 electrode-instrument system  at  the
 temperature of the samples For best
 results meters having automatic
 temperature compensation should be
 calibrated with solutions within 5C of
 the temperature of the stream to be
 measured The second source is the
 change of pH inherent in the sample
 at various temperatures This error is
 sample dependent and cannot be
 controlled, it should therefore be
 noted by reporting both the pH and
 temperature at the time of analysis


5   Apparatus

51   pH Monitor - A wide variety of
instruments are commercially
available with various specifications
and optional equipment For
unattended use, the monitor should
be equipped with automatic or fixed
1oO2
                        Dec 1982

-------
temperature compensation and with a
recorder or alarm function

5 2  Glass electrode - with shielded
cable between electrode and monitor
unless preamplification is used

5.3  Reference electrode - a
reference electrode with a constant
potential and with either a visible
electrolyte or viscous gel fill
NOTE  1  Combination electrodes in-
corporating both measuring and  refer-
ence functions are convenient to use
and are available with solid, gel-type fil-
ling  materials that require  minimal
maintenance

5 4  Temperature sensor - for
automatic compensator covering
general ambient temperature  range

5.5  Electrode mounting - to  hold
electrodes, may be flow through  (for
small flows),  pipe mounted or
immersion

6.   Reagents

6.1  Primary standard buffer salts are
available from the National Bureau of
Standards and should be used in
situations where extreme accuracy is
required

611   Preparation of reference
solutions from these salts require
some special precautions and
handling1 such as low conductivity
dilution water, drying ovens, and
carbon dioxide free purge gas These
solutions should be replaced at least
once each month

6.2  Secondary buffers may be
prepared from NBS salts or purchased
as a solution from commercial
vendors, Use of these commercially
available solutions, which have been
validated by comparison to NBS
standards, is recommended for
routine operation  These buffers  may
be retained for at least six months if
kept stoppered
7.   Calibration

7.1   Immersion type electrodes -
easily removed from mounting

7.1 1  The electrode should be
calibrated at a minimum of two points
that bracket the expected pH of the
water/waste and are approximately
three pH units or more apart
'National Bureau of Standards Special Publication
260
712  Repeat calibration
adjustments on successive portions of
the two buffer solutions until readings
are within 0 05 pH units of the buffer
value If calibration problems occur,
see 4 3

713  Because of the wide variety of
instruments available, no detailed
operating instructions are provided
Instead, the analyst should  refer to
the particular manufacturer s
instructions

714  Calibration against two buffers
should be carried out at least daily If
the pH of the fluid being measured
fluctuates considerably, the calibration
should be carried out more  often
Calibration frequencies may be
relaxed  if historical data supports a
longer period between calibration

7 2 Immersion type electrodes -
not easily removed from mounting

727  Collect a grab sample of the
flowing  material from a point as close
to the electrode as possible Measure
the pH of this grab sample as quickly
as possible with a laboratory - type pH
meter Adjust the calibration control
of the continuous monitor to the
reading  obtained

722  The temperature and condition
of the grab sample must remain
constant until its pH has been
measured by the laboratory pH  meter
The temperature of the sample should
be measured and the temperature
compensator of the laboratory pH
meter adjusted

723  The laboratory - type pH meter
should be calibrated prior to use
against two buffers as outlined in 7 1

724  The continuous pH monitoring
system should be initially calibrated
against two buffers as outlined in 7 1
before being placed into service
Recalibration (every 30 days) at two
points is recommended if at all
possible to ensure the measuring
electrode is in working order If this is
not possible, the use  of electrode
testing features for a broken or
malfunctioning electrode should be
considered when purchasing the
equipment

725  The indirect calibration should
be carried out at least once a day  If
the pH of the fluid being measured
fluctuates considerably, the calibration
should be carried out more  often
Calibration frequencies may be
relaxed if historical data support a
longer period between calibration
725  If the electrode can be
removed from the system, but with
difficulty, it should be directly
calibrated as in 7 1 at  least once a
month

7 3  Flow-through type electrode -
easily removed from its mounting

7 3 7  Calibrate using buffers as in
7 1  The buffers to be  used may be
the piocess stream itself as one
buffer  and as a second buffer after
adjustment of pH by addition of an
acid or base This will  provide the
larger volumes necessary to calibrate
this type electrode

732  Since the velocity of sample
flow-through a flow through electrode
can produce an offset  error in pH
reading, the user must have data on
hand to show that the offset is known
and compensation has been
accomplished

7 4  Flow-through type electrode -
not easily removed from its mounting

741  Calibrate as in 7 2

742  Quality control data must be
on hand to show the user is aware of
possible sample flow velocity effects

8    Procedure

8 1  Calibrate the monitor and
electrode system as outlined in
Section 7

8 2  Follow the manufacturer's
recommendation for operation  and
installation of the system

83  In wastewaters,  the electrode
may require periodic cleaning  After
manual cleaning, the electrode should
be calibrated as in 7 1 or 7 2 before
returning to service

8 4  The electrode must  be placed so
that the water or waste flowing past
the electrode is representative  of the
system

9    Calculations

91  pH meters read directly in pH
units  Reports pH to the nearest 0 1
unit and temperature to the nearest
C

10    Precision and  Accuracy

101   Because of the wide variability
of equipment and conditions and the
changeable character of the pH of
many process waters and wastes, the
precision of this method is probably
less than that of Method 150 1,
however, a precision of 0 1 pH unit
                                      Dec 1982
                                                                   ISO 2-2

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       be attamatAe )n the range of
 pH 6 0 to 8 0 Accuracy data for
 continuous monitoring equipment
 are not available at this time
 Bibliography
 1   Annual Book of ASTM
'Standards Part 31,  Water
 Standard 1293-78, Method D, p 226
 (1981)
                                    75023                    Dec  1982

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                              RESIDUE, FILTERABLE

                    Method  160.1  (Gravimetric,  Dried at 180C)

                                                                 STORE!  NO. 70300

 1     Scope and Application
      1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
           wastes
      1 2   The practical range of the determination is 10 mg/1 to 20,000 mg/1
2     Summary of Method
      21   A well-mixed sample is filtered through a standard glass fiber filter  The filtrate is
           evaporated and dried to constant weight at 180C
      22   If Residue,  Non-Filterable is being determined, the filtrate from that method may be
           used for Residue, Filterable
3     Definitions
      3 1   Filterable residue is defined as those solids capable of passing through a glass fiber filter
           and dried to constant weight at 180C
4     Sample Handling and Preservation
      4 1   Preservation of the sample is not practical, analysis  should begin as soon as possible
           Refrigeration or icing to 4C, to minimize microbiological decomposition of solids, is
           recommended
5     Interferences
      5 1   Highly mineralized waters containing significant concentrations of calcium, magnesium,
           chloride and/or  sulfate may  be hygroscopic and  will require prolonged  drying,
           desiccation and rapid weighing
      5 2   Samples containing high concentrations of bicarbonate will require careful and possibly
           prolonged drying at 180C to insure that all the bicarbonate is converted to carbonate
      5 3   Too much residue in the evaporating dish will crust over and entrap water that will not
           be driven off during drying Total residue should be limited to about 200 mg
6     Apparatus
      6 1   Glass fiber filter discs, 4 7 cm or 2 1 cm, without organic binder, Reeve Angel type 934-
           AH, Gelman type A/E, or equivalent
      6 2   Filter holder, membrane filter funnel or Gooch crucible adapter
      6 3   Suction flask, 500 ml
      6 4   Gooch crucibles, 25 ml (if 2 1 cm filter is used)
      6 5   Evaporating dishes,  porcelain,  100 ml volume (Vycor or  platinum dishes may be
           substituted)
      6 6   Steam bath
      67   Drying oven, 180C 2C
      6 8   Desiccator

Approved for NPDES
Issued 1971

                                          160 1-1

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     6 9   Analytical balance, capable of weighing to 0 1 mg
7    Procedure
     7 1   Preparation of glass fiber filter disc Place the disc on the membrane filter apparatus or
           insert into bottom of a suitable Gooch crucible While vacuum is applied, wash the disc
           with three successive 20 ml volumes of distilled water  Remove all traces of water by
           continuing to apply vacuum after water has passed through Discard washings
     7 2   Preparation of evaporating dishes If Volatile Residue is also to be measured heat the
           clean dish to 550 50C for one hour in a muffle furnace  If only Filterable Residue is to
           be measured heat the clean dish to 180 2C for one hour Cool in desiccator and store
           until needed  Weigh immediately before use
     7 3   Assemble the filtering apparatus and begin suction  Shake  the sample vigorously and
           rapidly transfer 100 ml to the funnel by means of a 100 ml graduated cylinder  If total
           filterable residue is low, a larger volume may be filtered
     7 4   Filter the sample through the glass fiber filter, rmse with three 10 ml portions of distilled
           water and continue to apply vacuum for about 3 minutes after filtration is complete to
           remove as much water as possible
     7 5   Transfer 100 ml (or a larger volume) of the filtrate to a weighed evaporating dish and
           evaporate to dryness on a steam bath
     7 6   Dry the evaporated sample for at least one hour at 180   2C Cool in a desiccator and
           weigh Repeat the drying cycle until a constant weight is obtained or until weight loss is
           less than 0 5 mg
8.   Calculation
     8 1   Calculate filterable residue as follows

           ,   ,.     ,      .,     (A - B)x 1,000
           Filterable residue, mg/1  =	
           where

           A = weight of dried residue + dish in mg
           B = weight of dish in mg
           C = volume of sample used in ml
9    Precision and Accuracy
     9.1   Precision and accuracy are not available at this time

                                       Bibliography

1.   Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 92, Method
     208B,(1975)
                                          160 1-2

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                          RESIDUE,  NON-FILTERABLE

                 Method  160.2  (Gravimetric, Dried at 103-105C)

                                                                 STORET NO. 00530

     Scope and Application
     1 1  This method is applicable to drinking, surface, and saline waters, domestic and industrial
          wastes
     1 2  The practical range of the determination is 4 mg/1 to 20,000 mg/1
     Summary of Method
     21  A well-mixed sample is filtered through a glass fiber filter, and the residue retained on the
          filter is dried to constant weight at 103-105C
     2 2  The filtrate from this method may be used for Residue, Filterable
     Definitions
     3 1  Residue, non-filterable, is defined as those solids which are retained by a glass fiber filter
          and dried to constant weight at 103-105C
     Sample Handling and Preservation
     4 1  Non-representative particulates such as leaves, sticks, fish, and lumps of fecal matter
          should be excluded from the sample if it is determined that their inclusion is not desired
          in the final result
     4 2  Preservation of the sample is not practical, analysis should begin as soon as possible
          Refrigeration or icing to 4C, to minimize microbiological decomposition of solids, is
          recommended
     Interferences
     5 1  Filtration apparatus, filter material, pre-washing, post-washing, and drying temperature
          are specified because these variables have been shown to affect the results
     5 2  Samples high in Filterable Residue (dissolved solids), such as saline waters, brines and
          some wastes, may be subject to a positive interference Care must be taken in selecting the
          filtering apparatus so that washing  of the filter and any dissolved solids in the filter (7 5)
          minimizes this potential interference
     Apparatus
     6 1  Glass fiber filter discs, without organic binder, such as Millipore AP-40, Reeves Angel
          934-AH, Gelman type A/E, or equivalent
          NOTE: Because of the physical nature of glass fiber filters, the absolute pore size cannot
          be controlled or measured Terms such as "pore size", collection efficiencies and effective
          retention are used to define this property  in glass fiber filters Values for these parameters
          vary for the filters listed above
     6 2  Filter support filtering apparatus  with  reservoir and a coarse (40-60 microns) fritted
          disc as a filter support
Approved for NPDES
Issued 1971

                                          160 2-1

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     NOTE: Many funnel designs are available m glass or porcelain  Some of the most
     common are Hirsch or Buchner funnels, membrane filter holders and Gooch crucibles
     All are available with coarse fritted disc
6 3  Suction flask
6 4  Drying oven, 103-105C
6 5  Desiccator
6 6  Analytical balance, capable of weighing to 0 1 mg
Procedure
7.1  Preparation of glass fiber filter disc Place the glass  fiber filter on the membrane filter
     apparatus or insert into bottom of a suitable Gooch  crucible with wrinkled surface up
     While vacuum is applied, wash the disc with three successive 20 ml volumes of distilled
     water Remove all traces of water by continuing to apply vacuum after water has passed
     through Remove filter from membrane filter apparatus or both crucible and filter if
     Gooch crucible is used, and dry in an oven at  103-105C for one hour  Remove to
     desiccator and store until needed  Repeat the drying cycle until a constant weight is
     obtained (weight loss is less than 0 5 mg) Weigh immediately before use After weighing,
     handle the filter or crucible/filter with forceps or tongs only
7 2  Selection of Sample Volume
     For a 4.7 cm diameter filter,  filter 100 ml of sample If weight of captured residue is less
     than 1 0 mg, the sample volume must be increased to provide at least 1 0 mg of residue If
     other filter diameters are used, start with a sample volume equal to 7 ml/cm2 of filter area
     and collect at least a weight of residue proportional to the 1 0 mg stated above
     NOTE: If during filtration of this initial volume the filtration rate drops rapidly, or if
     filtration time exceeds 5 to 10 minutes, the following scheme is recommended Use an
     unweighed glass fiber filter of choice affixed in the filter assembly Add a known volume
     of sample to the filter funnel and record the time elapsed after selected volumes have
     passed through the filter Twenty-five ml increments for timing are suggested Continue
     to record the time and  volume increments until fitration rate drops rapidly  Add
     additional sample if the filter funnel volume is inadequate to reach a reduced rate  Plot
     the observed tune versus volume filtered Select the proper filtration volume as that just
     short of the time a significant change in filtration rate occurred
7 3  Assemble the filtering apparatus and begin suction Wet the filter with a small volume of
     distilled water to seat it against the fritted support
7.4  Shake the sample vigorously and quantitatively transfer the predetermined sample
     volume selected in 7 2 to the filter using a graduated cylinder Remove all traces of water
     by continuing to apply vacuum after sample has passed through
7 5  With suction on, wash the graduated cylinder, filter, non-filterable residue and filter
     funnel wall with three portions of distilled water allowing complete drainage between
     washing Remove all traces  of water by continuing to  apply vacuum after water has
     passed through
     NOTE: Total volume of wash water used should equal approximately 2 ml per cm2 For a
     4 7 cm filter the total volume is 30 ml
                                     160 2-2

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7 6  Carefully remove the filter from the filter support  Alternatively, remove crucible and
     filter from crucible adapter Dry at least one hour at 103-105C Cool in a desiccator and
     weigh  Repeat the drying cycle until a constant weight is obtained (weight loss is less than
     05mg)
Calculations
8 1  Calculate non-filterable residue as follows
      TVT   PI.   ui    A       n  (A - B)X 1,000
      Non-filterable residue, mg/1 = *	'
     where

     A  weight of filter (or filter and crucible) + residue in mg
     B = weight of filter (or filter and crucible) in mg
     C = ml of sample filtered
Precision and Accuracy
9 1  Precision data are not available at this time
9 2  Accuracy data on actual samples cannot be obtained

                                  Bibliography

NCASI TechmcarBulletm No  291, March 1977  National Council of the Paper Industry for
Air and Stream Improvement, Inc , 260 Madison Ave , NY
                                     160 2-3

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                                  RESIDUE, TOTAL

                 Method 160.3 (Gravimetric,  Dried at 103-105C)

                                                                 STORET  NO. 00500

      Scope and Application
      1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
           wastes
      1 2   The practical range of the determination is from 10 mg/1 to 20,000 mg/1
      Summary of Method
      21   A well mixed aliquot of the sample is quantitatively transferred to  a pre-weighed
           evaporating dish and evaporated to dryness  at 103-105C
      Definitions
      3 1   Total  Residue is defined as the sum of  the  homogenous suspended and dissolved
           materials m a sample
      Sample Handling and Preservation
      4 1   Preservation of the sample is not practical, analysis should begin as soon as possible
           Refrigeration or icing to 4C, to minimize microbiological  decomposition of solids, is
           recommended
      Interferences
      5 1   Non-representative particulates such as leaves, sticks, fish  and lumps of fecal matter
           should be excluded from the sample if it is determined that their inclusion is not desired
           in the final result
      5 2   Floating oil and grease, if present, should be included m the sample and dispersed by a
           blender device before ahquotmg
      Apparatus
      6 1   Evaporating dishes, porcelain, 90 mm, 100 ml capacity (Vycor or platinum dishes may
           be substituted and smaller size dishes may be used if required )
      Procedure
      7 1   Heat the clean evaporating dish to 103-105C for one hour,  if Volatile Residue is to be
           measured, heat at 550 50C for one hour in a muffle furnace  Cool, desiccate, weigh and
           store in desiccator until ready for use
      7 2   Transfer a measured aliquot of sample to the pre-weighed dish and evaporate to dryness
           on a steam bath or in a drying oven
           721 Choose an aliquot of sample sufficient to contain a residue of at least 25 mg  To
               obtain a weighable residue, successive  aliquots of sample may be added to the same
               dish
           722 If evaporation is performed m a drying oven,  the temperature should be lowered to
               approximately 98C to prevent boiling  and splattering of the sample
Approved for NPDES
Issued 1971

                                         160 3-1

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      7 3   Dry the evaporated sample for at least 1 hour at 103-105C Cool in a desiccator and
           weigh Repeat the cycle of drying at 103-105C, cooling, desiccating and weighing until a
           constant weight is obtained or until loss of weight is less than 4% of the previous weight,
           or 0 5 mg, whichever is less
8     Calculation
      8.1   Calculate total residue as follows
           Total rescue,
           where

           A = weight of sample + dish in mg
           B = weight of dish in mg
           C = volume of sample in ml
9.   Precision and Accuracy
     9.1   Precision and accuracy data are not available at this time

                                       Bibliography

1.   Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 91, Method
     208A, (1975)
                                         160 3-2

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                               RESIDUE, VOLATILE

                  Method  160.4  (Gravimetric, Ignition  at 550C)

                                                         STORET  NO.  Total 00505
                                                                 Non-Filterable 00535
                                                                      Filterable 00520

     Scope and Application
     1 1  This method determines the weight of solid material combustible at 550C
     1 2  The test is useful in obtaining a rough approximation of the amount of organic matter
          present in the solid fraction of sewage,  activated  sludge, industrial wastes, or bottom
          sediments
     Summary of Method
     2 1  The residue  obtained from the determination of total, filterable or non-filterable residue
          is ignited at 550C in a muffle furnace The loss of weight on ignition is reported as mg/1
          volatile residue
     Comments
     3 1  The test is subject to many errors due to loss of water of crystallization, loss of volatile
          organic matter prior to combustion, incomplete oxidation of certain complex organics,
          and decomposition of mineral salts during combustion
     3 2  The results  should not be considered an  accurate measure of organic carbon in the
          sample, but may be useful in the control of plant operations
     3 3  The principal source of error in the determination is failure to obtain a representative
          sample
     Sample Handling and Preservation
     4 1  Preservation of the sample is not practical, analysis should  begin as soon as possible
          Refrigeration or icing to 4C, to  minimize microbiological  decompostion of solids is
          recommended
     Precision and Accuracy
     5 1  A collaborative study involving three laboratories  examining four samples by means of
          ten replicates showed  a standard  deviation of  +11 mg/1 at  170 mg/1 volatile residue
          concentration
     Reference
     6 1  The procedure to be used for this determination is found in
          Standard Methods for the Examination  of Water and Wastewater, 14th Edition, p 95,
          Method 208E, (1975)
Approved for  NPDES
Issued 1971
                                         160 4-1

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                              SETTLEABLE  MATTER


                      Method 160.5 (Volumetric, Imhoff Cone)


                                                                STORET NO.  50086

      Scope and Application
      1 1  This method is applicable to surface and saline waters, domestic and industrial wastes
      1 2  The practical lower limit of the determination is about 0 2 ml/l/hr
      Summary of Method
      2 1  Settleable matter is measured volumetncally with an Imhoff cone
      Comments
      3 1  For some samples, a separation of settleable and floating materials will occur, in such
           cases the floating materials are not measured
      32  Many  treatment  plants,  especially plants equipped   to  perform  gravimetric
           measurements, determine  residue non-filterable (suspended solids), m preference to
           settleable matter, to insure that floating matter is included in the analysis
      Precision and Accuracy
      4 1   Data on this determination are not available at this time
      References
      5 1   The procedure to be used for this determination is found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 95,
           Method 208F, Procedure 3a (1975)
Approved for NPDES
Issued  1974
                                        160 5-1

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                                  TEMPERATURE


                            Method 170.1  (Thermometric)


                                                               STORET NO. 00010

  1    Scope and Application

      1 1  This method is applicable to drinking, surface, and saline waters, domestic and industrial
           wastes
 2    Summary of Method

      2 1  Temperatuf e measurements may be made with any good grade of mercury-filled or dial
           type centigrade thermometer, or a thermistor
 3    Comments

      3 1  Measurement  device should be routinely checked against a precision thermometer
           certified by the National Bureau of Standards
 4    Precision and Accuracy
      4 1  Precision and accuracy for this method have not been determined
 5    Reference
      5 1  The procedure to be used for this determination is found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition D 125
           Method 212 (1975)
Approved for NPDES
Issued  1971
                                       170 1-1

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                                       TURBIDITY
                             Method 180.1  (Nephelometric)
                                                                   STORET NO. 00076
  1     Scope and Application
       1 1   This method is applicable to drinking, surface, and saline waters in the range of turbidity
            from 0 to 40 nephelometnc turbidity units (NTU) Higher values may be obtained with
            dilution of the sample
            NOTE 1: NTU's are considered comparable to the previously reported Formazm
            Turbidity Units (FTU) and Jackson Turbidity Units (JTU)
 2     Summary of Method
       2.1   The method is based upon a comparison of the intensity of light scattered by the sample
            under defined conditions with the intensity of light scattered by  a standard reference
            suspension The higher the intensity of scattered light, the higher the turbidity Readings,
            in NTU's, are made in a nephelometer designed according to specifications outlined in
            Apparatus  A  standard suspension of Formazm,  prepared under  closely defined
            conditions, is used to calibrate the instrument
            2 1 1 Formazm polymer is used as the turbidity reference suspension for water because it
                 is more reproducible than other types of standards previously used for turbidity
                 standards
            2 1 2 A commercially  available  polymer standard is  also approved for  use for the
                National Interim Primary Drinking Water Regulations  This standard is identified
                as AMCO-AEPA-1 available from Amco Standard International, Inc
 3    Sample Handling and Preservation
      3 1   Preservation of the sample is not practical, analysis should begin as soon as possible
            Refrigeration or icing to 4C, to  minimize microbiological decomposition of solids, is
            recommended
 4    Interferences
      4 1  The presence of floating debris and coarse sediments which settle out rapidly will give
           low readings Finely divided air bubbles will affect the results in a positive manner
      4 2  The presence of true color, that is the color of water which is due to dissolved substances
           which absorb light, will cause turbidities to be low, although this effect is generally not
           significant with finished waters
 5     Apparatus
      5 1   The turbidimeter shall consist of a nephelometer with light source  for illuminating the
           sample and one or more photo-electric detectors with a readout device to indicate the
           intensity of light scattered at  right angles to the path of the incident light   The
           turbidimeter should be  so designed that little  stray light reaches  the detector in the

Approved for  NPDES and  SDWA
Issued 1971
Editorial revision  1974
Editorial revision  1978
                                          180 1-1

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     absence of turbidity and should be free from significant drift after a short warm-up
     period
5 2  The sensitivity of the instrument should permit detection of a turbidity difference of 0 02
     unit or less in waters having turbidities less than 1 unit  The instrument should measure
     from 0 to 40 units turbidity Several ranges will be necessary to obtain both adequate
     coverage and sufficient sensitivity for low turbidities
5 3  The sample tubes to be used with the available instrument must be of clear, colorless
     glass They should be kept scrupulously clean, both inside and out, and discarded when
     they become scratched or etched They must not be handled at all where the light strikes
     them, but should be provided with sufficient extra length, or with a protective case, so
     that they may be handled
5 4  Differences in physical design of turbidimeters will cause differences in measured values
     for turbidity even though the same suspension is used for calibration To minimize such
     differences, the following design criteria should be observed
     541 Light  source   Tungsten lamp  operated  at  a  color   temperature  between
           2200-3000K
     542 Distance traversed by incident light and scattered light within the sample tube
           Total not to exceed 10 cm
     543 Detector Centered at 90 to the incident light path and not to exceed 30 from
           90 The Detector, and filter system if used, shall have a spectral peak response
           between 400 and 600nm
5 5  The Hach Turbidimeter, Model 2100 and 2100 A, is in wide use and has been found to be
     reliable, however, other instruments meeting the above design criteria are acceptable
Reagents
6.1  Turbidity-free water Pass distilled water through a 0 45u pore size membrane filter if
     such filtered water shows a lower turbidity than the distilled water
6 2  Stock formazin turbidity suspension
     Solution 1 Dissolve 1 00 g hydrazine sulfate, (NH2)2H2SO4, in distilled water and dilute
     to 100 ml in a volumetric flask
     Solution 2 Dissolve 10 00 g hexamethylenetetramme in distilled water and dilute to 100
     ml in a volumetric flask
     In a 100 ml volumetric flask, mix 5 0 ml Solution 1 with 5 0 ml Solution 2  Allow to stand
     24 hours at 25  3C, then dilute to the mark and mix
6 3  Standard formazin turbidity suspension Dilute 10 00 ml stock turbidity suspension to
      100 ml with turbidity-free water  The turbidity of this suspension is defined as 40 units
      Dilute  portions  of the standard turbidity suspension  with turbidity-free  water as
      required
      6 3 1 A new stock turbidity suspension should be prepared each month  The standard
           turbidity suspension and dilute turbidity standards should be prepared weekly by
           dilution of the stock turbidity suspension
6 4   The AMCO-AEPA-1 standard as supplied  requires no preparation or dilution prior to
           use
                                      180 1-2

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  Procedure
  7 1   Turbidimeter calibration The manufacturer's operating instructions should be followed
       Measure standards on the turbidimeter covering the range of interest If the instrument is
       already calibrated in standard turbidity units, this procedure will check the accuracy of
       the calibration scales At least one standard should be run m each instrument range to be
       used  Some  instruments permit adjustments of sensitivity so that  scale values will
       correspond to turbidities  Reliance on a manufacturer's solid scattering standard for
       setting overall instrument sensitivity for all ranges is not an acceptable practice unless the
       turbidimeter has been shown to be free of drift on all ranges If a pre-cahbrated scale is
       not supplied, then  calibration curves should  be prepared  for  each range of  the
       instrument
 7 2   Turbidities less than 40 units Shake the sample to  thoroughly disperse the solids  Wait
       until air bubbles disappear then pour the sample into the turbidimeter tube Read  the
       turbidity directly from the instrument scale or from the appropriate calibration curve
 7 3    Turbidities exceeding 40 units Dilute the sample with one or more volumes of turbidity-
       free water until the turbidity falls below 40 units  The turbidity of the original sample is
       then computed from the turbidity of the diluted sample and the dilution factor For
       example, if 5 volumes of turbidity-free water were added to 1 volume of sample, and the
       diluted sample showed a turbidity of 30 units, then the turbidity of the original sample
       was 180 units
       7 3 1 The Hach  Turbidimeters, Models 2100 and 2100A, are equipped with 5 separate
           scales 0-0 2, 0-1 0, 0-100, and 0-1000 NTU  The upper scales are to be used only
           as indicators of required dilution volumes to reduce readings to less than 40 NTU
           NOTE 2: Comparative  work performed in the MDQAR Laboratory indicates a
           progressive error on sample turbidities  in excess of 40 units
 Calculation
 8 1   Multiply sample readings by appropriate dilution to obtain final reading
 8 2   Report results as follows

                    	                                  Record to Nearest
              00-10                                           005
              1-10                                             01
             10-40                                             ,
            40 - 100                                             5
           100 - 400                                            10
          400 - 1000                                            50
              >1Q00                                           100

Precision and Accuracy
91  In a single laboratory (EMSL), using surface water samples at levels of 26,41, 75 and 180
     NTU, the standard deviations were 0 60, 0 94,  12 and  4 7 units, respectively
9 2  Accuracy data are not available at this time
                                     180 1-3

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                                     Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D1889-71, p 223 (1976)
2.    Standard Methods for the Examination of Water and Wastewater, 14th  Edition,  p 132,
     Method 214A, (1975)
                                         180 1-4

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                                        METALS

                             (Atomic Absorption Methods)

  1     Scope and Application
       1 1   Metals in solution may be readily determined by atomic absorption spectroscopy The
            method is simple, rapid, and applicable to a large number of metals in drinking, surface,
            and saline waters, and domestic and industrial wastes  While drinking waters free of
            particulate matter may be analyzed directly, domestic and industrial wastes require
            processing to solubihze suspended material  Sludges, sediments and other solid type
            samples may also be analyzed after proper pretreatment
       1 2   Detection limits, sensitivity and optimum ranges of the metals will vary with the various
            makes and models of satisfactory atomic absorption spectrophotometers  The  data
            shown in Table  1, however, provide some indication of the actual concentration ranges
            measurable by  direct aspiration  and using furnace techniques  In  the  majority  of
            instances the concentration range shown in the table by direct aspiration may be
            extended much lower with scale expansion and conversely extended upwards by using a
            less sensitive wavelength or by rotating the burner head  Detection limits by direct
            aspiration may also be extended through concentration of the sample and/or through
            solvent extraction techniques Lower concentrations may also be determined using the
            furnace techniques The concentration ranges given in Table 1 are somewhat dependent
            on equipment such as the type of spectrophotometer and furnace accessory, the energy
            source and the degree of electrical expansion of the output signal  When using furnace
            techniques, however, the analyst should be cautioned as to possible chemical reactions
            occurring at  elevated temperatures  which  may result  in either  suppression or
            enhancement of the analysis element To insure valid data with furnace techniques, the
            analyst must examine each matrix for interference effects (see 521) and if detected, treat
           accordingly using either successive dilution, matrix modification or method of standard
           additions (see 8 5)
      1 3   Where direct aspiration atomic  absorption techniques  do not provide  adequate
           sensitivity,  m addition to the furnace procedure, reference is made to specialized
           procedures such as the gaseous hydride method for arsenic and selenium, the cold vapor
           technique for mercury, and  the  chelation-extraction procedure for selected metals
           Reference to approved colonmetnc methods is also made
      1 4   Atomic absorption  procedures are provided as the methods of choice, however, other
           instrumental methods  have also been shown to  be capable of producing precise  and
           accurate analytical data These instrumental techniques include emission spectroscopy,
           X-ray fluorescence, spark source mass spectroscopy, and anodic stripping to name but a
           few The analyst should be cautioned  that  these methods are  highly  specialized
           techniques requiring a high degree of skill to interpret results and obtain valid data

Approved for NPDES and  SDWA
Issued 1969
Editorial revision 1974 and 1978

                                       METALS-1

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           These above mentioned techniques are presently considered as alternate test procedures
           and approval must be obtained prior to their use
2.   Summary of Method
     2.1   In direct aspiration atomic absorption spectroscopy a sample is aspirated and atomized
           in a flame  A light beam from a hollow cathode lamp whose cathode is made of the
           element to be determined is directed through the flame into a monochromator, and onto
           a detector that measures the amount of light absorbed Absorption depends upon the
           presence of free unexcited ground state atoms m the flame Since the wavelength of the
           light beam is characteristic of only the metal being determined, the light energy absorbed
           by the flame is a measure of the concentration of that metal in the sample This principle
           is the basis of atomic absorption spectroscopy
     2.2   Although methods  have been reported for the analysis of solids by atomic absorption
           spectroscopy (Spectrochim Acta, 24B  53, 1969) the technique generally is limited to
           metals in solution or solubihzed through some form of sample processing
           221 Preliminary treatment of  wastewater  and/or industrial effluents is  usually
                necessary because of  the  complexity  and variability of the sample  matrix
                Suspended material must be subjected to a solubihzation process before analysis
                This process may vary because of the metals to be determined and the nature of the
                sample being  analyzed  When the breakdown of organic material is necessitated,
                the process should include a wet digestion with nitric acid
           2 2 2 In those instances where complete  characterization of a sample is desired, the
                suspended material must be analyzed separately  This may be accomplished  by
                filtration and acid digestion of the suspended material Metallic constituents in this
                acid digest are  subsequently  determined and the sum of the  dissolved  plus
                suspended concentrations will then provide the total concentrations present The
                sample  should be  filtered as soon  as possible after  collection and the filtrate
                acidified immediately
           223 The total sample may also be treated with acid without prior filtration to measure
                what may be termed "total recoverable" concentrations
     2 3   When  using the  furnace  technique  in conjunction  with an  atomic  absorption
           spectrophotometer, a representative aliquot of a sample is placed in the graphite tube in
           the furnace, evaporated to dryness, charred, and atomized  As a greater percentage of
           available analyte atoms are vaporized and dissociated for absorption in the tube than the
           flame, the use of small sample volumes  or detection of low concentrations of elements is
           possible The principle is essentially the same as with direct aspiration atomic absorption
           except  a furnace, rather than a flame, is used to atomize the sample Radiation from a
           given excited element is passed through the vapor containing ground state atoms of that
           element The intensity of the transmitted radiation decreases in proportion to the amount
           of the ground state element in the vapor
                                        METALS-2

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                                                    TABLE 1

                                Atomic Absorption  Concentration Ranges0'


                                Direct Aspiration                        Furnace Procedure'4 S)

Metal
Aluminum
Antimony
Arsenic0'
Banum(p)
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Gold
Indmm(p)
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum(p)
Nickel(p)
Osmium
Palladmm(p)
Platmum(p)
Potassium
Rhemum(p)
Rhodium(p)
Ruthenium
Selenium"'
Silver
Sodium
Thallium
Tin
Titanium (p)
Vanadium (p)
Zinc
Detection
Limit
mg/1
01
02
0002
01
0005
0005
001
005
005
002
01
3
003
01
0001
001
00002
01
004
03
01
02
001
5
005
02
0002
001
0002
01
08
04
02
0005
Optimum
Concentration
Sensitivity
mg/1
1
05
-
04
0025
0025
008
025
02
01
025
8
012
05
0007
005
-
04
015
1
025
2
004
15
03
05
-
006
0015
05
4
2
08
002
Range
mg/1
5
1
0002 -
1
005
005
02
05
05
02
05
20
03
1
002
01
00002 -
1
03
2
05
5
01
50
1
1
0002 -
01
003
1
10
5
2
005
50
40
002
20
2
2
7
10
5
5
20
500
5
20
0,5
3
001
40
5
100
15
75
2
1000
30
50
002
4
1
20
300
100
100
1
Detection
Limit
ug/1
3
3
1
2
02
01

1
1
1
1
30
1
1

02

1
1
20
5
20

200
5
20
2
02

1
5
10
4
005
Optimum
Concentration
Range
ug/1
20
20
5
10
1
05 -

5
5
5
5
100
5
5

1 _

3
5
50
20
100

500
20
100
5 _
1

5
20
50
10
02 -
200
300
100
200
30
10

100
100
100
100
1500
100
100

30

60
50
500
400
2000

5000
400
2000
100
25

100
300
500
200
4
(1)

(2)
(3)
(4)
(5)
The  concentrations shown are not contrived values and should be obtainable with  any satisfactory atomic absorption
spectrophotometer
Gaseous hydride method
Cold vapor technique
For furnace sensitivity values consult instrument operating manual
The listed furnace values are those expected when using a 20 u\ injection and normal gas flow except in the case of arsenic and
selenium where gas interrupt is used The symbol (p) indicates the use of pyrolytic graphite with the furnace procedure
                                                 METALS-3

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The metal atoms to be measured are placed in the beam of radiation by increasing the temperature of
the furnace thereby causing the injected specimen to be volatilized A monochromator isolates the
characteristic radiation from the hollow cathode lamp and a photosensitive device measures the
attenuated transmitted radiation
3    Definition of Terms
     3 1   Optimum Concentration Range A range, defined by limits expressed in concentration,
           below which scale expansion must be used and above which curve correction should be
           considered This range will vary with the sensitivity of the instrument and the operating
           condition employed
     3 2   Sensitivity  The  concentration in  milligrams  of metal per liter that produces  an
           absorption of 1 %
     3 3   Detection Limit  Detection limits can be expressed as either an instrumental or method
           parameter The limiting factor of the former using acid water standards would be the
           signal to noise ratio and degree of scale expansion used, while the latter would be more
           affected by the sample matrix and preparation procedure used  The Scientific Apparatus
           Makers Association (SAMA) has approved the following definition for detection limit
           that concentration of an element which would yield an absorbance equal to twice the
           standard deviation of a series of measurements of a solution, the concentraton of which is
           distinctly detectable above, but close to blank absorbance measurement  The detection
           limit values listed in Table I and on the individual analysis sheets are to be considered
           minimum working limits achievable with the procedures given in this manual These
           values may differ from the optimum detection limit reported by the various instrument
           manufacturers
      34   Dissolved Metals  Those constituents (metals)  which will pass through a  045 u
           membrane filter
      3 5   Suspended Metals  Those constituents (metals) which are retained by a 0 45 u membrane
           filter
      3 6   Total Metals The concentration of metals determined on an unfiltered sample following
           vigorous digestion (Section 4 1  3), or the sum of the concentrations of metals in both the
           dissolved and suspended fractions
      3 7   Total Recoverable Metals  The concentration of metals in an unfiltered sample following
           treatment with hot dilute mineral acid (Section 414)
 4    Sample Handling and Preservation
      4.1   For the determination of trace metals, contamination and loss are of prime concern  Dust
           in the laboratory  environment,  impurities in  reagents and  impurities  on  laboratory
           apparatus which the sample contacts  are  all sources of potential contamination  For
           liquid samples,  containers can  introduce either positive or negative errors in  the
           measurement of trace metals  by (a) contributing  contaminants  through leaching or
           surface desorption and  (b) by depleting concentrations through adsorption  Thus the
           collection and treatment of the sample prior to analysis requires particular attention The
           sample bottle whether borosihcate glass, polyethylene polypropylene or Teflon should
           be thoroughly washed with detergent and tap water, rinsed with  1  1 nitric acid, tap
                                         METALS-4

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water, 1 1 hydrochloric acid, tap water and finally deionized distilled water in that
order
NOTE 1:  Chromic acid may be useful to remove organic deposits from glassware,
however, the analyst should be cautioned that the glassware must be thoroughly rinsed
with water to  remove the last traces of chromium  This is especially important if
chromium is to be included in the  analytical scheme  A commercial product
NOCHROMIXavailable from Godax Laboratories, 6 Vanck St New York, N Y
10013, may be used in place  of chromic acid [Chromic acid should not be used with
plastic bottles ]
NOTE 2 If it can be documented through an active analytical quality control program
using spiked  samples, reagent and sample blanks, that certain steps in the cleaning
procedure are not required for routine samples, those steps may be eliminated from the
procedure
Before collection of the sample a decision must be made as to the type of data desired, i e,
dissolved, suspended, total or total  recoverable  For container preference, maximum
holding time and sample preservation at time of collection see Table 1 in the front part of
this manual Drinking water samples containing suspended and setteable material should
be prepared using the total recoverable metal procedure (section 4 1 4)
4 1 1 For the determination  of dissolved  constituents the sample must  be filtered
     through a 0 45 u membrane filter as soon as practical after collection (Glass or
     plastic  filtering apparatus using  plain, non-grid marked, membrane filters  are
     recommended to avoid possible contamination ) Use the first 50-100 ml to rinse
     the filter  flask Discard this portion  and collect the required  volume of filtrate
     Acidify the filtrate with 1 1 redistilled HNO3 to a pH of <2  Normally, 3 ml of
     (1 1) acid per liter should be sufficient to preserve the sample (See Note  3) If
     hexavalent chromium is to be included in the analytical scheme, a portion of the
     filtrate  should be  transferred  before acidification to a separate container and
     analyzed as soon as possible using Method 2184 Analyses performed on a sample
     so treated shall be reported as "dissolved" concentrations
NOTE 3  If a precipitate is formed upon acidification, the filtrate should be digested
using 413 Also, it has been suggested (International Biological Program, Symposium
on Analytical Methods, Amsterdam, Oct 1966) that additional acid, as much as 25 ml of
cone HCl/liter, may be required to stabilize certain types of highly buffered samples if
they are  to be stored for any  length of time Therefore, special precautions should be
observed for preservation and storage of unusual samples intended for metal analysis
412 For the determination of suspended metals a representative volume of unpreserved
     sample  must be filtered through a 0 45 u membrane filter When considerable
     suspended material is present, as little as 100 ml of a well mixed sample is filtered
     Record  the volume filtered and transfer the membrane filter containing the
     insoluble material to a 250 ml Griffin beaker and add 3 ml cone redistilled HNO3
     Cover the beaker with a watch glass and heat gently  The warm acid will soon
     dissolve the membrane  Increase the  temperature of the hot plate and digest the
     material When the acid has nearly evaporated, cool the beaker and watch glass
     and add another 3 ml of cone redistilled HNO3 Cover and continue heating until
                             METALS-5

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     the digestion  is  complete,  generally indicated  by a  light colored digestate
     Evaporate to near dryness (DO NOT BAKE), add 5 ml distilled HC1 (1 1) and
     warm the beaker gently to dissolve any soluble material (If the sample is to be
     analyzed by the furnace procedure, 1 ml of 1 1 distilled HNO3 per 100 ml dilution
     should be substituted for the distilled 1 1 HC1) Wash down the watch glass and
     beaker walls with deiomzed distilled water and filter the sample to remove silicates
     and other insoluble material that could clog the atomizer Adjust the volume to
     some predetermined value based on the expected concentrations of metals present
     This volume will vary depending on the metal to be determined The sample is now
     ready for analysis Concentrations so determined shall be reported as "suspended"
     (See Note 4)
     NOTE 4:  Certain  metals such as  antimony arsenic,  gold, indium, mercury,
     osmium, palladium, platimum, rhenium, rhodium, ruthenium, selenium, silver,
     thallium, tin and titanium require modification of the digestion procedure and the
     individual sheets for these metals should be consulted
413 For the determination of total metals the sample is acidified with 1  1 redistilled
     HNO3 to a pH of less than 2 at the time of collection The sample is not filtered
     before processing Choose a volume of sample appropriate for the expected level of
     metals If much suspended material is present, as little as 50-100 ml of well mixed
     sample will most probably be sufficient  (The sample volume required may also
     vary proportionally with the number of metals to be determined )
     Transfer a  representative aliquot of the well mixed sample to a Griffin beaker and
     add 3 ml of cone redistilled HNO3 Place the beaker on a hot plate and evaporate
     to near dryness cautiously, making certain that the sample does not boil (DO NOT
     BAKE ) Cool the beaker and add another 3 ml portion of cone  redistilled HNO3
     Cover the  beaker with a watch glass and return to the hot plate  Increase the
     temperature of the hot plate so that a gentle reflux action occurs  Continue heating,
     adding additional acid as necessary,  until the digestion is complete (generally
     indicated when the digestate is light in color or does not change in appearance with
     continued refluxmg) Again, evaporate to near dryness and cool  the beaker Add a
      small  quantity of redistilled  1 1 HC1 (5 ml/100 ml of final solution) and warm the
      beaker to  dissolve any precipitate or residue resulting from evaporation (If the
      sample is to be analyzed by the furnace procedure, substitute distilled HNO3 for 1 1
      HC1 so that the final dilution contains 0 5% (v/v) HNO3) Wash down the beaker
      walls and watch glass with distilled water and filter the sample to remove silicates
      and other insoluble material that could clog the atomizer Adjust the volume to
      some predetermined value based on the expected metal concentrations  The sample
      is now ready  for analysis  Concentrations so determined shall be reported as
      "total" (see Note 4)
 4 1.4 To determine total recoverable metals, acidify the entire sample at the time of
      collection  with cone  redistilled HNO3, 5 ml/1 At the time of analysis a 100 ml
      aliquot of well mixed sample is transferred to a beaker or flask Five ml of distilled
      HC1 (1 1)  is added and the  sample heated on a steam bath  or hot plate until the
                              METALS-6

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           volume has been reduced to 15-20 ml making certain the samples do not boil (If
           the sample is being prepared for furnace analysis, the same process should be
           followed except HC1 should be omitted ) After this treatment the sample is filtered
           to remove silicates and other insoluble material that could clog the atomizer and
           the  volume  adjusted to  100 ml   The  sample is  then  ready for  analysis
           Concentrations so determined shall be reported as "total"  (See Notes 4, 5, and 6 )
           NOTE 5: The analyst should be cautioned that this digestion procedure may not be
           sufficiently vigorous to destroy certain metal complexes if a colonmetnc procedure
           is to be employed for the final  determination  When this is suspect,  the more
           vigorous digestion given in 4 1 3 should be followed
           NOTE 6: For drinking water analyses by direct aspiration, the final volume may be
           reduced to effect up to a  10X concentration of the  sample, provided the total
           dissolved solids m the original sample do not exceed 500 mg/1, the determination
           is corrected for any non-specific absorbance and there is no loss by precipitation
Interferences
5 1   Direct Aspiration
     511  The   most  troublesome  type   of  interference   in   atomic  absorption
           spectrophotometry  is  usually termed "chemical" and  is caused  by lack of
           absorption of  atoms  bound  in molecular  combination in  the flame  This
           phenomenon can occur when the flame is not sufficiently hot to dissociate the
           molecule, as in the case of phosphate interference with magnesium, or because the
           dissociated atom is  immediately oxidized to a compound that will not dissociate
           further at the temperature of the flame The addition of lanthanum will overcome
           the phosphate interference in the magnesium, calcium and barium determinations
           Similarly, silica interference in the determination of manganese can be eliminated
           by the addition of calcium
     512  Chemical interferences may also be eliminated by separating the metal from the
           interfering material While complexmg agents are primarily employed to increase
           the sensitivity of the analysis, they may  also be used to  eliminate or reduce
           interferences
     5 1 3  The presence of high dissolved solids m the sample may result in  an interference
           from non-atomic absorbance such as light scattering If background correction is
           not available, a non-absorbing wavelength should be checked Preferably, high
           solids type samples should be extracted (see 511 and 9 2)
     514  lomzation interferences occur where the flame temperature is sufficiently high to
           generate the removal of an electron from a neutral atom, giving a positive charged
           ion This type of interference can generally be controlled by the addition, to both
           standard and sample solutions, of a large excess of an easily ionized element
     515  Although  quite  rare, spectral  interference  can  occur  when  an absorbing
           wavelength of an element present in the sample but  not  being determined falls
           within the width of the absorption line of the element of interest The results of the
           determination will  then  be erroneously high, due to  the  contribution of the
           interfering element to the atomic absorption signal  Also,  interference can occur
                                  METALS-7

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          when resonant energy from another element in a multi-element lamp or a metal
          impurity m the lamp cathode falls within the bandpass of the slit setting and that
          metal is present in the sample This type of interference may sometimes be reduced
          by narrowing the slit width
5.2  Flameless Atomization
     521 Although the problem of oxide formation  is greatly reduced  with furnace
          procedures because atomization occurs in an inert atmosphere, the technique is
          still subject to chemical and matrix interferences The composition of the sample
          matrix can have a major effect on the analysis It is those effects which must be
          determined and taken into consideration in the analysis of each different matrix
          encountered To help verify the absence of matrix or chemical interference use the
          following procedure Withdraw from the sample two equal ahquots To one of the
          ahquots add a known amount of analyte and dilute both ahquots to the same
          predetermined volume [The dilution volume should be based on the analysis of the
          undiluted sample Preferably, the dilution should be 1 4 while keeping in mind the
          optimum concentration range of the analysis Under no circumstances should the
          dilution be less than 1 1] The diluted ahquots should then be analyzed and the
          unspiked results multiplied by the dilution factor should  be compared  to the
          original determination  Agreement of the results (within 10%) indicates the
          absence of interference Comparison of the actual signal from the spike to the
          expected response from the analyte in an aqueous standard should help confirm the
          finding from the dilution analysis Those samples which indicate the presence of
          interference, should be treated in one or more of the following ways
                a    The  samples should be  successively  diluted  and  reanalyzed  to
                     determine if the interference can be  eliminated
                b    The matrix of the sample should be modified in the furnace  Examples
                     are the addition of ammonium nitrate to remove alkali  chlorides,
                     ammonium phosphate to retain  cadmium, and nickel nitrate  for
                     arsenic  and   selenium  analyses   [ATOMIC   ABSORPTION
                     NEWSLETTER Vol  14, No 5, p  127, Sept-Oct 1975]  The mixing of
                     hydrogen with the inert  purge gas has also been used to suppress
                     chemical interference The hydrogen acts as a reducing agent and aids
                     in molecular dissociation
                c    Analyze the sample by method of standard additions while noting  the
                     precautions and limitations of its use (See 8 5)
     522 Gases generated m the furnace during atomization may have molecular absorption
          bands encompassing the analytical wavelength  When this occurs, either the use of
          background correction or choosing an alternate wavelength outside the absorption
          band should eliminate this interference Non-specific broad band absorption
          interference can also be compensated for with background correction
     523 Interference from a smoke-producing sample matrix can sometimes be reduced by
          extending the charring time at a higher temperature or utilizing an ashing cycle in
                                  METALS-8

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          the presence of air  Care must be taken, however, to prevent loss of the analysis
          element
     524 Samples containing large amounts of organic materials should be oxidized by
          conventional acid digestion prior to being placed in the furnace In this way broad
          band absorption will be minimized
     525 From anion interference studies in the graphite furnace it is generally accepted that
          nitrate is the preferred anion  Therefore nitric acid is preferable for any digestion or
          solubihzation step If another acid in addition to HN03 is required a minimum
          amount should be used  This applies particularly to hydrochloric and to a lesser
          extent to sulfunc and phosphoric acids
     526 Carbide formation resulting from the chemical environment of the furnace has
          been observed with certain  elements that form carbides at high temperatures
          Molybdenum may be cited as an example When this takes place, the metal will be
          released very slowly from the carbide as atomization continues For molybdenum,
          one may be required to atomize for 30 seconds or more before the signal returns to
          baseline levels This problem is greatly reduced and the sensitivity increased  with
          the use of pyrolytically-coated graphite
     527 lonization interferences have to date not been reported with furnace techniques
     528 For comments on spectral interference see section 515
     529 Contamination of the sample can be a major source of error because of the extreme
          sensitivities achieved with the furnace The sample preparation work area should
          be kept scrupulously clean All glassware should be cleaned as directed in part 6 9
          of the Atomic Absorption Methods section of this manual  Pipet tips have  been
          known to be a source of contamination  If suspected, they should be acid soaked
          with 1 5 HNO3 and rinsed thoroughly with tap and deiomzed water The use of a
          better grade plpet tip can greatly reduce this problem  It is very important that
          special attention be given to  reagent blanks in both analysis and the correction of
          analytical results Lastly, pyrolytic graphite because of the production process and
          handling can become  contaminated  As many as five to  possibly ten  high
          temperature burns may be required to clean the tube before use
Apparatus
6 1  Atomic absorption spectrophotometer  Single or dual channel, smgle-or double-beam
     instrument having a grating monochromator, photomultipher detector, adjustable slits, a
     wavelength range of 190 to 800 nm, and provisions for interfacing with a  strip chart
     recorder
6 2  Burner The burner recommended by the particular instrument manufacturer should be
     used For certain elements the nitrous oxide burner is required
6 3  Hollow cathode lamps  Single element lamps are to be preferred but multi-element lamps
     may be used Electrodeless discharge lamps may also be used when available
6 4  Graphite furnace Any furnace device capable of reaching the specified temperatures is
     satisfactory
                                   METALS-9

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      6 5   Strip chart recorder A recorder is strongly recommended for furnace work so that there
           will be a permanent record and any problems with the analysis such as drift, incomplete
           atomization, losses during charring, changes in sensitivity, etc, can be easily recognized
      6 6   Pipets Microhter with disposable tips  Sizes  can  range from 5 to 100 microhters as
           required NOTE 7  Pipet tips which are white m color, do not contain CdS, and have
           been found suitable for research work are available from Ulster Scientific, Inc 53 Mam
           St Highland, NY 12528 (914) 691-7500
      6.7   Pressure-reducing valves The supplies of fuel and oxidant shall be maintained at
           pressures somewhat higher than the controlled operating pressure of the instrument by
           suitable valves
      6 8   Separatory flasks 250 ml, or larger, for extraction with organic solvents
      6 9   Glassware  All  glassware, linear  polyethylene, polyproplyene or  Teflon  containers,
           including  sample bottles, should be washed with detergent, rinsed with tap water, 1 1
           nitric acid, tap water, 1 1 hydrochloric acid, tap water  and deiomzed distilled water in
           that order [See Notes  1  and 2 under (4 1)  concerning the use of chromic acid and the
           cleaning procedure ]
      610 Borosilicate glass distillation apparatus
7.    Reagents
      7 1   Deiomzed distilled water  Prepare by passing distilled water through a mixed bed of
           cation and amon exchange resins Use deiomzed distilled water for the preparation of all
           reagents, calibration standards, and as dilution water
      7 2   Nitric acid (cone )   If metal impurities are found to be present, distill reagent grade
           nitric acid m a borosilicate glass distillation apparatus or use a spectrograde acid
           Caution   Distillation should be performed in hood with protective sash in place
                 721 Nitric Acid (1 1)  Prepare all dilution  with deiomzed, distilled water by
                      adding the cone acid to an equal volume of water
      7.3   Hydrochloric acid (11)   Prepare all solution of reagent grade hydrochloric acid and
           deiomzed  distilled water If metal impurities are found to be present, distill this mixture
           from a borosilicate glass distillation apparatus or use a spectrograde acid
      7 4   Stock standard metal solutions  Prepare as directed in (8 1) and under the individual
           metal procedures Commercially available stock standard solutions may also be used
      7 5   Calibration  standards   Prepare a series of standards  of the metal by dilution of the
           appropriate stock metal solution to cover the concentration range desired
      7 6   Fuel and  oxidant   Commercial grade  acetylene is generally acceptable  Air may be
           supplied from a compressed  air line, a laboratory compressor, or from  a  cylinder of
           compressed air Reagent grade nitrous oxide is also required for certain determinations
           Standard,  commercially available argon and nitrogen are required for furnace work
      7 7   Special reagents for the extraction procedure
           771  Pyrrohdine dithiocarbamic acid (PDCA) "see footnote"  Prepare by adding 18
                 ml of analytical reagent grade pyrrohdme to 500 ml of chloroform in a liter flask
The name pyrrohdine dithiocarbamic acid (PDCA),  although commonly referenced in the scientific
literature is ambiguous   From the chemical reaction of pyrrohdme and carbon disulfide a more
proper name would be  1-pyrrolidme carbodithioic acid,  PCDA (CAS Registry No  25769-03-3)

                                        METALS-10

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           (See Note 8) Cool and add 15 ml of carbon disulfide in small portions and with
           swirling Dilute to 1 liter with chloroform  The solution can be used for several
           months if stored in a brown bottle in a refrigerator

     NOTE  8: An acceptable grade of pyrrolidme  may be  obtained  from the Aldnch
     Chemical Co , 940 West St Paul Ave , Milwaukee, WI 53233(414,273-3850)

     772 Ammonium hydroxide, 2N  Dilute  13 ml  cone  NH4OH to 100 ml with
           deiomzed distilled water
     773 Bromophenol blue indicator (1 g/hter) Dissolve 0 1 g bromophenol blue m 100
           ml of 50 percent ethanol or isopropanol
     774 HC1,2 5% v/v Dilute 2 ml redistilled HC1 (6N) to 40 ml with deiomzed distilled
           water
Preparation of Standards and Calibration
8 1   Stock standard solutions are prepared from high purity metals, oxides or nonhygroscopic
     reagent grade salts using deiomzed distilled water and redistilled nitric or hydrochloric
     acids (See individual analysis sheets for specific instruction ) Sulfuric or phosphoric
     acids should be avoided as they produce an adverse effect on many elements The stock
     solutions are prepared at concentrations of 1000 mg of the metal per liter Commercially
     available standard solutions may also be used
8 2   Calibration standards are prepared by diluting the stock metal solutions at the time of
     analysis For best results, calibration standards should be prepared fresh each time an
     analysis is to be made and discarded after use Prepare a blank and  at least four
     calibration standards in graduated amounts in the appropriate range The calibration
     standards should be prepared using the same type of acid or combination of acids and at
     the same concentration as will result in the samples following processing  As filtered
     water samples are preserved with 1 1 redistilled HNO3  (3 ml per liter),  calibration
     standards for these analyses should be similarly prepared with HNO3  Beginning with
     the blank and working toward the highest standard, aspirate the solutions and record the
     readings Repeat the operation with both the calibration standards and the samples a
     sufficient number of times  to secure a reliable average reading for each solution
     Calibration standards for furnace procedures should be prepared as described on the
     individual sheets for that metal
8 3   Where the sample matrix is so complex that viscosity, surface tension and components
     cannot be accurately matched with standards, the method of standard addition must be
     used This technique relies on the addition of small, known amounts of the analysis
     element to portions of the samplethe  absorbance  difference between those and the
     original solution  giving the slope  of the calibration curve  The  method of standard
     addition is described in greater detail in (8 5)
                                  METALS-11

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8.4  For those instruments which do not read out directly in concentration, a calibration
     curve is prepared to cover the appropriate concentration range Usually, this means the
     preparation of standards which produce an absorption of 0 to 80 percent The correct
     method is to convert the percent absorption readings to absorbance and plot that value
     against concentration The following relationship is used to convert absorption values to
     absorbance

          absorbance = log (100/%T) == 2-log % T
          where % T = 100-% absorption

     As the curves are frequently nonlinear, especially at high absorption values, the number
     of standards should be increased m that portion of the curve
8 5  Method of Standard Additions   In this method, equal volumes of sample are added to a
     deiomzed distilled water blank and to three standards containing different known
     amounts of the test element The volume of the blank and the standards must be the
     same The absorbance of each solution is determined and then plotted on the vertical axis
     of a graph, with the concentrations of the known standards plotted on the  horizontal
     axis  When the resulting line is extrapolated  back to zero absorbance, the point of
     interception of the abscissa is the concentration of the unknown The abscissa on the left
     of the ordmate is scaled the same as on the right side, but in the opposite direction from
     theordmate An example of a plot so obtained is shown in Fig  1
                    o>
                    o
                    o
                    J3
   Zero
 Absorbance
                                                                       Concentration
     'Cone of
      Sample
Addn 0
No Addn
Addn I
Addn of 50%
of Expected
Amount
Addn 2
Addn of 100%
of Expected
Amount
Addn 3
Addn of 150%
of Expected
Amount
                     FIGURE 1.  STANDARD  ADDITION  PLOT
                                 METALS-12

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     The method of standard additions can be very useful, however, for the results to be valid
     the following limitations must be taken into consideration
           a)    the absorbance plot of sample and standards must  be linear over the
                concentration range of concern For best results the slope of the plot should
                be nearly the same as the slope of the aqueous standard curve If the slope is
                significantly different (more than 20%) caution should be exercised
           b)    the effect of the interference should  not  vary as the ratio  of analyte
                concentration to sample matrix changes and the standard addition should
                respond in a similar manner as the analyte
           c)    the determination must be free of spectral interference and corrected for non-
                specific background interference
General Procedure for Analysis by Atomic Absorption
9 1   Direct Aspiration  Differences between the various makes and models of satisfactory
     atomic absorption spectrophotometers prevent the formulation of detailed instructions
     applicable to every instrument  The analyst should follow the manufacturer's operating
     instructions for his particular instrument In general, after choosing the proper hollow
     cathode lamp for the analysis, the lamp should be allowed to warm up for a minimum of
     15  minutes unless operated in a double beam mode During this period, align the
     instrument, position the monochromator at the correct wavelength, select  the proper
     monochromator sht  width, and  adjust the hollow cathode current according to the
     manufactuerer's recommendation Subsequently, light the flame and regulate the flow of
     fuel and oxidant, adjust the burner and nebulizer flow rate for maximum percent
     absorption and stability, and balance the photometer  Run a series of standards of the
     element under analysis and construct a calibration curve by plotting the concentrations
     of the standards against the absorbance  For those instruments which read directly in
     concentration set the curve corrector to read out the proper concentration Aspirate the
     samples and determine the concentrations either directly or from the calibration curve
     Standards must be run each time a sample or series of samples are run
     911  Calculation -  Direct determination of liquid samples Read the metal value in
           mg/1  from the calibration curve  or directly from the readout system of the
           instrument
           9111     If dilution of sample was required

           mg/1 metal in sample  = A

           where

           A   mg/1 of metal indiluted aliquot from calibration curve
           B =  ml of deiomzed distilled water used for dilution
           C=  ml of sample aliquot
                                  METALS-13

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           912 For samples containing particulates

                mg/1 metal m sample = /


                where

                A =  mg/1 of metal m processed sample from calibration curve
                V =  final volume of the processed sample m ml
                C =  ml of sample aliquot processed
           913 For solid samples report all concentrations as mg /kg dry weight
                9131     Dry sample:


                mg metal/kg sample = g


                where

                A =  mg/1 of metal m processed sample from calibration curve
                V =  final volume of the processed sample in ml
                D=  weight of dry sample in grams
                9132     Wet sample

                                    A x V
                mg metal/kg sample = . v, p
                                    W X sr

                where

                A =  mg/1 of metal in processed sample from calibration curve
                V =  final volume of the processed sample m ml
                W = weight of wet sample in grams
                P =  % solids
     9 2   Special Extraction Procedure   When the concentration of the metal is not sufficiently
           high  to determine directly, or when considerable dissolved solids are present in the
           sample, certain metals may be chelated and extracted with organic solvents Ammonium
           pyrrohdine dithiocarbamate (APDC) (see footnote) in methyl isobutyl ketone (MIBK) is
           widely  used  for this purpose and is  particularly useful for zinc,  cadmium, iron,
           manganese, copper, silver, lead and chromium"1"6  Tn-valent chromium does not react
           with APDC unless it has first been converted to the hexavalent form [Atomic Absorption
           Newsletter 6, p 128  (1967)]  This  procedure is  described  under  method 218 3
The name ammonium pyrrohdine dithiocarbamate (APDC) is somewhat ambiguous and should more
properly be called ammonium, 1 -pyrrohdine carbodithioate (APCD), CAS Registry No 5108-96-3

                                      METALS-14

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Aluminum, beryllium, barium and strontium also do not react with APDC While the
APDC-MIBK chelatmg-solvent system can be used satisfactorily, it is possible to
experience difficulties (See Note 9 )
NOTE 9:  Certain metal chelates,  manganese-APDC m particular, are not stable in
MIBK and will redissolve into the aqueous phase on standing The extraction of other
metals is sensitive to both shaking rate and time  As with cadmium, prolonged extraction
beyond  1 minute, will reduce the extraction efficiency, whereas 3 minutes of vigorous
shaking is required for chromium
Also, when multiple metals are to be determined either larger sample volumes must be
extracted or individual extractions made for each metal being determined The acid form
of APDC-pyrrohdme dithiocarbamic acid prepared directly in chloroform as described
by Lakanen, [Atomic Absorption Newsletter 5, p 17 (1966)], (see 771) has been found
to be most advantageous In this procedure the more dense chloroform layer allows for
easy combination of multiple extractions which are carried out over a broader pH range
favorable to multielement extractions Pyrrohdme dithiocarbamic acid in chloroform is
very stable and may be stored in a brown bottle in the refrigerator for months  Because
chloroform is used as the solvent, it  may not be aspirated into the flame The following
procedure is suggested
921 Extraction  procedure with   pyrrohdme  dithiocarbamic  acid  (PDCA)  in
     chloroform
     9211     Transfer 200 ml of sample into a 250 ml separatory funnel, add 2 drops
                bromphenol blue indicator solution (7 7 3) and mix
     9212     Prepare a blank and sufficient standards in the same manner and adjust
                the volume of each to approximately 200 ml with  deiomzed  distilled
                water All of the metals to be determined may be combined into single
                solutions at the appropriate concentration levels
     9213     Adjust the pH by addition of 2N NH4OH solution (7 7 2) until a blue
                color persists  Add HC1 (7 7 4) dropwise until the blue color just
                disappears, then add 2 0 ml HC1 (7 7 4) in excess The pH at this point
                should be 2 3  (The pH adjustment may be made with a pH meter
                instead of using indicator )
     9214     Add 5 ml of PDCA-chloroform reagent (7 7 1) and shake vigorously
                for 2 minutes  Allow the phases to separate and dram the chloroform
                layer into a 100 ml beaker (See NOTE 10 )
                NOTE 10: If  hexavalent chromium is to be extracted,  the aqueous
                phase must be readjusted back to a pH of 2 3  after the addition of
                PDCA-chloroform and  maintained at  that pH throughout  the
              r extraction  For multielement extraction, the pH may adjusted upward
                after the chromium has been extracted
                            METALS-15

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           9.2 1 5     Add a second portion of 5 ml PDCA-chloroform reagent (7 7 1) and
                     shake vigorously for 2  minutes  Allow  the phases to separate and
                     combine the chloroform phase with that obtained in step (9214)
           9216     Determine the pH of the aqueous phase and adjust to 4 5
           9217     Repeat step (9214) again combining the solvent extracts
           9218     Readjust the pH to 5 5, and extract a fourth tune Combine all extracts
                     and evaporate to dryness on a steam bath
           9.2 1 9     Hold the beaker at a 45 degree angle, and slowly add 2 ml of cone
                     distilled nitric acid, rotating the beaker to effect thorough contact of
                     the acid with the residue
           9 2 1 10   Place the  beaker on a low temperature  hotplate  or steam bath and
                     evaporate just to dryness
           92111   Add 2 ml of nitric acid (1 1) to the beaker and heat for 1 minute Cool,
                     quantitatively transfer the solution to a  10 ml volumetric flask and
                     bring to volume with distilled water The sample is  now ready for
                     analysis
     9.2 2 Prepare a calibration curve by plotting absorbance versus the concentration of the
           metal standard (ug/1) in the  200 ml extracted standard solution To calculate
           sample concentration  read  the metal value in ug/1 from the calibration curve or
           directly from the readout system of the instrument  If dilution of the sample was
           required use the following equation

           mg/1 metal m sample


                where

                     Z = ug/1 of metal in diluted aliquot from calibration curve
                     B = ml of deiomzed distilled water used for dilution
                     C = ml of sample aliquot
9 3  Furnace Procedure  Furnace devices (flameless atomization) are a most useful means of
     extending detection limits Because of differences between various makes and models of
     satisfactory instruments, no  detailed operating instuctions  can  be  given for  each
     instrument  Instead,  the analyst  should follow the instructions provided by the
     manufacturer of his particular instrument and use as a guide the temperature settings
     and other instrument conditions listed on the individual analysis sheets  which are
     recommended for the Perkm-Elmer HGA-2100 In addition, the following points may be
     helpful
     931 With flameless atomization, background correction becomes  of high importance
           especially below 350 nm This is  because certain samples, when atomized, may
           absorb  or scatter light from the hollow cathode lamp It can be caused by the
           presence of gaseous molecular species, salt particules, or smoke in the sample
                                  METALS-16

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      beam If no correction is made, sample absorbance will be greater than it should be,
      and the analytical result will be erroneously high
 9 3 2 If during atomization all the analyte is not volatilized  and removed from the
      furnace, memory effects will occur This condition is dependent on several factors
      such  as the volatility of the element and its chemical form,  whether pyrolytic
      graphite is used, the rate of atomization and furnace design  If this situation is
      detected through blank burns, the tube should be cleaned by operating the furnace
      at full power for the required time period as needed at  regular intervals in the
      analytical scheme
 933 Some of the smaller size furnace devices, or newer furnaces equipped with feedback
      temperature control (Instrumentation Laboratories MODEL 555, Perkm-Elmer
      MODELS HGA 2200 and HGA 76B, and Varian MODEL CRA-90) employing
      faster rates of atomization, can be operated using lower atomization temperatures
      for shorter time periods than those listed in this manual
 934 Although prior digestion of the sample in many cases is not required providing a
      representative aliquot of sample can be pipeted into the furnace, it will provide for a
      more uniform matrix and possibly lessen matrix effects
 935 Inject a measured microhter aliquot of sample into the furnace and atomize If the
      concentration found is greater than the highest standard, the sample should be
      diluted in the same acid matrix and reanalyzed The use of multiple injections can
      improve accuracy and help detect furnace pipetting errors
 9 3 6 To verify the absence of interference, follow the procedure as given in part 521
9 3 7 A check standard should be run approximately after every 10 sample injections
      Standards are run in part to monitor the life and performance of the graphite tube
      Lack  of reproducibihty or significant change in  the signal  for the  standard
      indicates that the tube should be  replaced  Even though tube life depends on
      sample matrix and atomization temperature, a conservative estimate would be that
      a tube will last at least 50 firings  A pyrolytic-coatmg would extend that estimate
      by a factor of 3
938  Calculation-For determination of metal concentration by the furnace Read the
      metal value in ug/1 from the calibration curve or directly from the readout system
      of the instrument
      9381     If different size furnace injection volumes are used for samples than for
                standards
                          -'(*)
ug/1 of metal in sample =

where

Z =  ug/1 of metal read from calibration curve or readout system
S =  ul volume standard injected into furnace for calibration curve
U =  ul volume of sample injected for analysis
                            METALS-17

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     9382    If dilution of sample was required but sample injection volume same as
               for standard
     ug/1 of metal in sample = Z
     where

     Z = ug/1 metal in diluted aliquot from calibration curve
     B = ml of deiomzed distilled water used for dilution
     C = ml of sample aliquot
939 For sample containing particulates
     ug/1 of metal in sample = Z  I  TT
     where

     Z = ug/1 of metal in processed sample from calibration curve (See 9381)
     V = final volume of processed sample in ml
     C = ml of sample aliquot processed
9310     For solid samples Report all concentrations as mgAg dry weight
          9 3 10 1    Dry sample
                           x1,000  ^V
     mg metal/kg sample =
     where

     Z =  ug/1 of metal in processed sample from calibration curve (See 9381)
     V =  final volume of processed sample in ml
     D=  weight of dry sample in grams
           93102    Wet sample
                             [,000 ' V
     mg metal/kg sample =
                              W  X A

     where

     Z =  ug/1 of metal in processed sample from calibration curve (See 9381)
     V =  final volume of processed sample in ml
     W = weight of wet sample in grams
     P =  % solids
                             METALS-18

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10   Quality Control For Drinking Water Analysis
     10 1  Minimum requirements                   l
          10 1 1      All  quality control data should be maintained  and available for easy
                     reference or inspection
          10 1 2      An unknown performance sample (when available) must be analyzed once
                     per year for the metals measured Results must be within the control limit
                     established by  EPA If problems arise, they should be corrected,  and a
                     follow-up performance sample should be analyzed
     10 2  Minimum Daily control
          10 2 1      After a calibration curve compojsed  of a minimum of a reagent blank and
                     three standards has been prepared, subsequent calibration curves must be
                     verified by use  of at least a reagent blank and one standard at or near the
                     MCL Daily checks must be within 10 percent of original curve
          1022      If 20 or more samples per day are [analyzed, the working standard curve must
                     be verified by running an additional standard at or near the MCL every 20
                     samples Checks must be within i 10 percent of original curve
     10 3  Optional Requirements
          10 3  1      A current service contract should be in effect on balances and the atomic
                     absorption spectrophotometer   j
          1032      Class S weights should be available to make periodic checks on balances
          1033      Chemicals should be dated upon receipt of shipment and replaced as needed
                    or before shelf life has been exceedjed
          10 3 4     A known reference  sample (when available)  should be analyzed once per
                    quarter for the metals measured |xhe measured value should be within the
                    control limits established by EPA'
          10 3 5     At least one duplicate sample should  be run every 10 samples, or with each
                    set of samples to verify precision of the method Checks should be within the
                    control limit established by EPA
          10 3 6     Standard  deviation  should  be  obtained  and  documented  for  all
                    measurements being conducted   |
          10 3 7     Quality  Control charts or a tabulation of mean and standard deviation
                    should be used to document vahdi(y of data on a daily ba
basis
                                     METALS-19

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                              United States
                              Environmental Protection
                              Agency
                              Environmental Monitoring and
                              Support Laboratory
                              Cincinnati OH 45268
                              Research and Development
ERA
Test  Method
                              Inductively Coupled  Plasma
                              Atomic  Emission Spectrometric
                              Method  for Trace  Element
                              Analysis  of Water  and
                              WastesMethod  200.7
                              1   Scope and Application

                              1 1  This method may be used for
                              the determination of dissolved
                              suspended, or total elements in
                              drinking water, surface water
                              domestic and industrial wastewaters

                              1 2  Dissolved elements are
                              determined in filtered and acidified
                              samples Appropriate steps must be
                              taken in all analyses to ensure that
                              potential interference are taken into
                              account This is especially true when
                              dissolved solids exceed 1 500 mg/L
                              (See 5 )

                              1 3  Total elements are determined
                              after appropriate digestion procedures
                              are performed  Since digestion
                              techniques increase the dissolved
                              solids content of the samples,
                              appropriate steps must be taken to
                              correct for potential interference
                              effects (See 5 )
                              1 4 Table 1 lists elements for which
                              this method applies along with
                              recommended wavelengths and
                              typical estimated instrumental
                              detection limits using conventional
                              pneumatic nebuhzation Actual
                              working detection limits are sample
                              dependent and as the sample matrix
                              varies, these concentrations may also
                              vary In time, other elements may be
                              added as more information becomes
                              available and as required

                               1 5  Because of the differences
                              between various makes and models of
                              satisfactory instruments, no detailed
                              instrumental operating instructions
                              can be provided Instead, the analyst
                              is referred to the instructions provided
                              by the manufacturer of the particular
                              instrument

                              2   Summary of Method

                              2 1   The method describes a
                              technique for the simultaneous or
                              sequential multielement
                              determination of trace elements in
                              solution The basis of the method is
                              the  measurement of atomic emission
                              by an optical spectroscopic technique
                              Samples are nebulized and the
                              aerosol that is produced is transported
                              to the plasma torch where excitation
                              occurs Characteristic atomic-line
                              emission spectra are produced by a
                              radio-frequency inductively coupled
                              plasma (ICP) The spectra are
                              dispersed by a grating spectrometer
                              and the intensities of the lines are
                              monitored  by photomultipher tubes
                              The photocurrents from the
                              photomultipher tubes are processed
                              and controlled by a computer system
                              A background correction technique is
                              required to compensate for variable
                              background contribution to the
                              Metals-2O
                                                   Dec 1982

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 determination of trace elements
 Background must be measured
 adjacent to analyte lines on samples
 during analysis The position selected
 for the background intensity
 measurement  on either or both sides
 of the analytical line, will be
 determined by the complexity of the
 spectrum adjacent to the analyte line
 The position used must be free of
 spectral interference and reflect the
 same change in background
 intensity as occurs at the analyte
 wavelength measured Background
 correction is not required in cases of
 line broadening where a background
 correction measurement would
 actually degrade the analytical result
 The possibility of additional
 interferences named in 5  1 (and tests
 for their presence as described in 5 2)
 should also be recognized and
 appropriate corrections made

 3    Definitions

 3 1  Dissolved  Those elements
 which will pass through a 0 45 /urn
 membrane filter

 3 2  Suspended  Those elements
 which are retained by a 0 45 fjm
 membrane filter

 3 3  Total  The  concentration
 determined on an  unfiltered sample
 following vigorous digestion (9 3) or
 the sum of the dissolved plus
 suspended concentrations (9 1 plus
 92)

 3 4  Total recoverable  The
 concentration determined on an
 unfiltered sample following treatment
 with hot dilute mineral acid (9 4)

 3 5  Instrumental detection limit 
 The concentration  equivalent to a
 signal, due to the analyte  which is
 equal to three times the standard
 deviation of a series of ten replicate
 measurements of a reagent blank
 signal at the same wavelength

 3 6  Sensitivity  The slope of the
 analytical curve, i e functional
 relationship between emission
 intensity and concentration

3 7 Instrument check standard  A
multielement standard of known
concentrations prepared by the
analyst to monitor and verify
instrument performance on a daily
basis  (See 761)

3 8  Interference check sample  A
solution containing both interfering
and analyte elements of known
concentration that can be used to
 verify background and mterelement
 correction factors (See 762)

 3 9 Quality control sample  A
 solution obtained from an outside
 source having known, concentration
 values to be used to verify the
 calibration standards (See 763)

 3 10  Calibration standards  a
 series of know standard solutions
 used by the analyst for calibration of
 the instrument (i e , preparation of the
 analytical curve) (See 7 4)

 311  Linear dynamic range  The
 concentration  range over which the
 analytical curve remains linear

 3 12  Reagent blank  A volume of
 deionized distilled water containing
 the same acid matrix as  the
 calibration standards carried through
 the entire analytical scheme (See
 752)

 3 13  Calibration blank   A volume
 of deionized  distilled water acidified
 with HNO3 and HCI  (See 751)

 3 14  Method of standard addition 
 The standard addition technique
 involves the use of the unknown and
 the  unknown plus a  known amount of
 standard  (See 1061)

 4   Safety

 4 1   The toxicity or  carcmogenicity of
 each reagent used in this method has
 not  been precisely defined  however
 each chemical  compound should be
 treated as a potential health hazard
 From this viewpoint  exposure to
 these chemicals must be reduced to
 the  lowest possible level by whatever
 means available  The laboratory is
 responsible for maintaining a current
 awareness file of OSHA regulations
 regarding the safe handling  of the
 chemicals specified in this method A
 reference file of material data
 handling sheets should also be made
 available to all  personnel involved in
 the chemical analysis Additional
 references to laboratory safety are
 available and have been identified
 (147 148 and 14 9) for  the
 information of the analyst

5    Interferences

5 1   Several types of interference
effects may contribute to  inaccuracies
in  the determination of trace
elements They can be summarized as
follows

511  Spectral interferences can be
categorized as 1) overlap of a spectral
line from another element, 2)
  unresolved overlap of molecular band
  spectra, 3) background contribution
  from continuous or recombination
  phenomena, and 4) background
  contribution from stray light from the
  line emission of high concentration
  elements  The first of these effects
  can be compensated by utilizing a
  computer  correction of the raw data,
  requiring the monitoring and
  measurement of the interfering
  element The second effect may
  require selection of an alternate
  wavelength  The third and fourth
  effects can usually be compensated by
  a background correction adjacent to
  the analyte line In addition, users of
  simultaneous multielement
  instrumentation must assume the
  responsibility of verifying the absence
  of spectral interference from an
  element that could occur in a sample
  but for which there is no channel in
  the instrument array Listed in  Table 2
  are some  interference effects for the
  recommended wavelengths given in
  Table 1  The data  in Table 2 are
  intended for use only as a
  rudimentary guide for the indication of
  potential spectral  interferences  For
  this purpose,  linear relations between
  concentration and  intensity for the
  analytes and the mterferents can be
  assumed
   The interference information  which
 was collected at the Ames Laboratory,1
 is expressed at analyte concentration
 eqivalents  (i e false analyte concen-
 trations) arising from 1OO mg/L of the
 mterferent element The suggested use
 of this information  is as follows
 Assume that arsenic (at 193 696 nm)
 is to be determined in a sample
 containing approximately 10 mg/L of
 aluminum  According to Table 2, 100
 mg/L of aluminum would yield  a false
 signal for arsenic equivalent to
 approximately 1 3 mg/L  Therefore,
 10 mg/L of aluminum  would result in
 a false signal for arsenic equivalent to
 approximately 0 13 mg/L The reader
 is cautioned that other analytical
 systems may exhibit somewhat
 different levels of interference than
 those shown in Table 2, and that the
 interference effects must be evaluated
 for each individual system

   Only  those  mterferents listed werp
 investigated and the  blank  spaces  in
 Table 2 indicate that measurable inter-
 ferences were not observed for the
 mterferent concentrations listed  in
 Table 3 Generally  interferences were
 discernible if they  produced peaks or
 background shifts corresponding to
 2-5% of the peaks generated  by the
'Ames Laboratory USDOE Iowa State University
Ames Iowa 50011
                                      Dec 1982
                                                                  Metals-21

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analyte concentrations also listed in
Table 3
  At present, information on the listed
silver and potassium wavelengths are
not available but it has been reported
that second order energy from the
magnesium 383 231 nm wavelength
interferes with the listed potassium line
at 766 491 nm

5.1.2  Physical interferences are
generally considered to be effects
associated with the sample nebuhza-
tion and transport processes  Such
properties as change in viscosity and
surface tension can cause significant
inaccuracies especially in samples
which may contain high dissolved
solids and/or acid concentrations The
use of a peristaltic pump may lessen
these interferences If these types of
interferences are operative, they must
be reduced by dilution of the sample
and/or utilization of standard addition
techniques Another problem which
can occur from high dissolved solids
is salt buildup at the tip of the
nebulizer This affects aersol flow-rate
causing instrumental drift Wetting
the argon prior to nebulization, the
use of a tip washer, or sample dilution
have been used to control this
problem. Also, it has been reported
that better control of the argon flow
rate improves instrument
performance This is accomplished
with the use of mass flow controllers

5 1.3  Chemical Interferences are
characterized by molecular compound
formation, lonlzation effects and
solute vaporization effects Normally
these effects are not pronounced with
the ICP technique, however, if
observed they can be minimized by
careful selection of operating
conditions (that is, incident power,
observation position, and so forth),  by
buffering of the sample, by matrix
matching, and by standard addition
procedures These types of
interferences can be highly dependent
on matrix type and the specific
analyte efement

5.2  It is recommended that
whenever a new or unusual sample
matrix is encountered, a series of
tests be performed prior to reporting
concentration data for analyte
elements These tests, as outlined in
521 through 524, will ensure the
analyst that neither positive nor
negative interference effects are
operative on any of the analyte el-
ements thereby distorting the
accuracy of the reported values

521  Serial dilutionIf the analyte
concentration is sufficiently high (min-
imally a factor of 10 above the instru-
mental detection limit after dilution),
an analysis of a dilution should agree
within 5 % of the original determina-
tion (or within some acceptable con-
trol limit (14 3) that has been estab-
lished for that matrix) If not, a
chemical or physical interference ef-
fect should be syspected

522  Spike additionThe recovery
of a spike addition added at a
minimum level of 10X the in-
strumental detection limit (maximum
100X) to the original determination
should be recovered to within 90 to
110 percent or within the established
control limit for that matrix If not, a
matrix effect should be suspected The
use of a standard addition analysis
procedure can usually compensate for
this effect Caution  The standard ad-
dition technique does not detect coin-
cident spectral overlap If suspected,
use of computerized compensation, an
alternate wavelength, or comparison
with an alternate method is recom-
mended  (See 523)

523  Comparison with alternate
method of analysisWhen investi-
gating a new sample matrix, compari-
son tests may be performed with other
analytical techniques such as atomic
absorption spectrometry, or other
approved methodology

524  Wavelength scanning of
analyte line region\i the appropriate
equipment is  available, wavelength
scanning can be performed to detect
potential spectral interferences

6   Apparatus

6 1  Inductively Coupled Plasma-
Atomic Emission Spectrometer

611  Computer controlled atomic
emission spectrometer with background
correction

612  Radiofrequency generator

613  Argon gas supply, welding
grade or better

6 2  Operating conditions   Because
of the differences between various
makes and models of satisfactory
instruments, no detailed operating
instructions can be  provided Instead,
the analyst should follow the
instructions provided by the
manufacturer of the particular
instrument Sensitivity, instrumental
detection limit, precision, linear dy-
namic range,  and interference effects
must be investigated and established
for each individual analyte line on that
particular instrument  It is the
responsibility of the analyst to verify
that the instrument configuration and
operating conditions used satisfy the
analytical requirements and to
maintain quality control data
confirming  instrument performance
and analytical results

7   Reagents  and standards

7 1  Acids used in the preparation
of standards and for sample processing
must be ultra-high purity grade or
equivalent  Redistilled acids are
acceptable

777  Acetic acid, cone  (sp gr  1 06)

7/2  Hydrochloric acid cone  (sp gr
1 19)

713  Hydrochloric acid, (1+1)  Add
500 ml cone HCI (sp gr 1 19) to 400
mL deiomzed, distnlled water and
dilute to 1 liter

714  Nitric acid cone (sp gr 1 41)

7/5  Nitric ac/o:(1+1)  Add 500 mL
cone  HN03 (sp  gr 1 41) to 400  ml
deiomzed, distilled water and dilute to
1 liter

7 2 Dionized distilled water Prepare
by passing distilled water through a
mixed bed of cation and anion ex-
change resins Use deiomzed, distilled
water for the preparation of all
reagents, calibration standards and as
dilution water The purity of this water
must be equivalent to ASTM Type II
reagent water of Specification D 1193
(146)

7 3 Standard stock solutions may be
purchased or prepared from ultra high
purity grade chemicals or metals All
salts must be dried for 1 h at  105C
unless otherwise  specified
(CAUTION  Many metal salts are ex-
tremely toxic and may be fatal if  swal-
lowed  Wash hands thoroughly after
handling ) Typical stock solution  pre-
paration procedures follow
731  Aluminum solution, stock,  1
mL = 100 yug Al  Dissolve 0 100  g of
aluminum metal in an acid mixture of 4
mL of (1+1) HCI and 1 mL of cone HNO3
in a beaker Warm gently to effect
solution When solution is complete,
transfer quantitatively to a liter flask,
add an additional  10 mL of (1 + 1) HCI
and dilute to 1 000 mL with deiomzed,
distilled water

732  Antimony solution stock, 1 mL
= 100 //g Sb Dissolve 0 2669 g K(SbO)
C^iH/iOe in deiomzed distilled water,
add 10 mL (1+1) HCI and dilute
to 1000 mL with deiomzed,  distilled
water
                                      Metals-22
                                                                 Dec  1982

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  733  Arsenic solution stock, 1 mL =
  TOO /jig As Dissolve 0 1320 g of As2O3
  in 100 mL of deiomzed, distilled water
  containing 0 4 g NaOH Acidify the
  solution with 2 mL cone HNO3 and
  dilute to 1,000 mL with deiomzed
  distilled Water

  734  Barium solution stock  1  mL
  = 100 ,ug Ba Dissolve 0 1516 g BaCI2
  (dried at 250C for 2 hrs) in 10 mL
  deiomzed, distilled water with 1 mL
  (1+1) HCI Add  100 mL(1+1) HCI
  and dilute to 1,000 mL with deiomzed,
  distilled water

  735  Beryllium solution  stock  1
  mL = 100 HQ Be Do not dry Dis-
  solve 1 966 g BeSCU  4 4H2O in
  deiomzed, distilled water  add 100 mL
  cone HN03 and dilute to 1 000 mL
  with deiomzed, distilled water

  736  Boron solution  stock, 1 mL
  = 100 //g B  Do not dry Dissolve
  0 5716 g anhydrous H3BO3  in deiomzed
  distilled water dilute to 1,000 mL
  Use a reagent meeting ACS specifica-
  tions, keep the  bottle tightly stoppered
  and store in a desiccator to prevent
  the entrance of atmospheric moisture

  737   Cadmium solution  stock  1
  mL = 100 fj.g Cd Dissolve 0 1142 g
  CdO in a minimum amount of (1 + 1)
  HNO3  Heat to increase rate of dis-
  solution Add 10 OmL cone HIM03
  and dilute to 1,000 mL with deiomzed,
  distilled water

  738   Calcium solution stock  1  mL
  = 100 ^g Ca Suspend 0 2498 g
  CaCO3 dried at  180C for 1  h before
  weighing in deiomzed distilled water
  and dissolve cautiously with a min-
  imum amount of (1 + 1) HN03 Add
  10 OmL cone HNO3 and dilute to
  1,000 mL with deiomzed distilled
 water

  739  Chromium solution  stock  1
  mL = 100 /jg Cr Dissolve 0 1923
 g of Cr03 m deiomzed, distilled
 water When solution is complete,
 acidify with 10 mL cone HNO3 and
 dilute to 1,000 mL with deiomzed
 distilled water

 73 JO  Cobalt solution stock 1
 mL = 100/jg Co Dissolve 0 1000 g
 of cobalt metal in a minimum amount
 of (1+1) HNO3 Add 100 mL (1+1) HCI
 and dilute to 1,000 mL with deiomzed
 distilled water

7311   Copper solution stock 1
mL = 100 fig Cu  Dissolve 0 1 252 g
CuO in a minimum amount of (1 + 1)
HNO3 Add 10 OmL cone HN03 and
dilute to 1 000 mL with deiomzed
distilled water
  7312  Iron solution  stock  1 mL
  = 100/ug Fe  Dissolve 0 1430 g
  Fe2O3 in a warm mixture of 20 mL
  (1+1) HCI and 2 mL of cone HNO3
  Cool, add an additional 5 mL of cone
  HN03 and  dilute to 1000 mL with
  deiomzed,  distilled water

  7313  Lead solution stock  1 mL
  = 100 fjg Pb  Dissolve 0 1599 g
  Pb(IMO3)2 in minimum amount of
  (1+1) HN03 Add 10 OmL cone HNO3
  and dilute  to 1,000 mL with deiomzed,
  distilled water

  7314  Magnesium solution stock 1
  mL = 100/ug  Mg Dissolve 0 1658 g
  MgO m a minimum amount of (1 + 1)
  HNO3 Add 10 OmL cone  HNO3 and
  dilute to 1,000 mL with deiomzed,
  distilled water

  73 15  Manganese solution  stock  1
  mL = 100yug  Mn Dissolve 0 1000 g
  of manganese metal in the acid mix-
  ture 10 mL cone  HCI and  1 mL cone
  HNO3, and  dilute to 1,000  mL with
  deiomzed distilled water

  7316  Molybdenum solution stock
  1 mL = 100 yt/g Mo Dissolve 0 2043 g
  (NH4)2MoCU m deiomzed distilled
  water and dilute to 1 000 mL

  7317  Nickel solution stock  1
  mL = 100 yug Ni  Dissolve 0 1000 g
  of nickel  metal in 10 mL hot cone
  HNO3, cool and dilute to 1,000 mL
  with deiomzed, distilled water

  7318 Potassium solution stock 1
  mL = 100 /ug K  Dissolve 0  1907 g
  KCI, dried at 110C  m deiomzed
 distilled water dilute to  1 000 mL

  7319 Selenium solution stock 1
 mL = 100 /ug Se  Do not dry Dissolve
 0 1 727 g H2SeO3 (actual assay 94 6%)
 in deiomzed distilled water and dilute
 to 1,000 mL

 7 3 20  Silica solution  stock  1 mL
 = 100y(/g  SiO2 Do not dry Dissolve
 0 4730 g Na2SiO3  9H20 in deiomzed
 distilled water  Add 10 0 mL cone
 HNO3 and dilute to 1,000 mL with
 deiomzed distilled water

 7 3 21  Silver solution stock  1
 mL = 100 fig Ag  Dissolve 0 1575 g
 AgNO3 in 100 mL of deiomzed  dis-
 tilled water  and 10 mL cone HNO3
 Dilute to 1 000 mL with deiomzed
 distilled water

 7 3 22 Sodium solution stock 1
 mL = 100 yug Na  Dissolve 0 2542 g
 NaCI in deiomzed distilled water
Add 10 OmL cone HNO3 and dilute
to 1 000 mL with  deiomzed  distilled
water
  7 3 23  Thallium solution, stock, 1
  mL = 100 yug Tl Dissolve 0 1303 g
  TINO3 iri deiomzed, distilled water
  Add 10 0 mL cone  HN03 and dilute
  to 1,000 mL with deiomzed, distilled
  water

  7 3 24  Vanadium solution  stock, 1
  mL = 100 fig V Dissolve 0 2297
  NH/A/Os m a minimum amount of
  cone  HN03  Heat to increase rafe
  of dissolution  Add  10 0 mL cone
  HN03 and dilute to 1,000 mL with
  deiomzed distilled water

  7 3 25  Zinc solution stock  1  mL
  = 100 //g Zn  Dissolve 0 1245 g ZnO
  in a minimum  amount of dilute HIMOa
  Add 10 0 mL cone  HNO3 and dilute
  to 1,000 mL with deiomzed, distilled
  water

  7 4  Mixed calibration standard so-
  lutionsPrepare mixed calibration
  standard solutions by combining ap-
  propriate volumes of the stock solu-
  tions in volumetric flasks (See 7 4 1
  thru 745) Add 2 mL of (1 + 1)
  HCI and dilute  to 100 mL with
 deiomzed, distilled water (See Notes
  1 and 6 ) Prior  to preparing the mixed
 standards each stock solution should
 be analyzed separately to determine
 possible spectral interference or the
 presence of impurities Care should
 be taken when preparing the  mixed
 standards that  the elements are com-
 patible and stable Transfer the mixed
 standard solutions to a FEP fluoro-
 carbon or unused polyethylene bottle
 for storage Fresh mixed standards
 should be prepared  as needed with
 the  realization that concentration can
 change on aging Calibration stand-
 ards must be initially verified  using
 a quality control sample and moni-
 tored weekly for stability (See 763)
 Although not specifically required,
 some typical calibration  standard com-
 binations follow when using those
 specific wavelengths listed in  Table
 1

 741  Mixed standard solution I
 Manganese beryllium cadmium lead
and zinc

 742  Mixed standard solution II
 Barium, copper, iron vanadium  and
cobalt


 743  Mixed standard solution III
 Molybdenum  silica  arsenic, and
selenium
744  Mixed standard solution IV
Calcium sodium potassium alumi-
num chromium and nickel
                                     Dec 1982
                                                                Meta/s-23

-------
 745 Mixed standard solution V
Antimony, boron, magnesium, silver,
and thallium
  NOTE 1 If the addition of silver
to the recommended acid combination
 results in an initial precipitation,
add 15 ml of deionized distilled
water and warm the flask until the
solution clears Cool and dilute to 100
 mL with deionized, distilled water For
 this acid combination the silver con-
 centration should be limited to 2
 mg/L Silver under these conditions
 Is stable in a tap water matrix
 for 30 days  Higher concentrations
 of silver require additional HCI

7 5  Two types of blanks are required
for the analysis The calibration blank
(3 13) is used in establishing the
analytical curve while the reagent
blank (3 12) is used to correct for
possible contamination resulting from
varying amounts of the acids used m
the sample processing

 7 5.1  The  calibration blank is pre-
pared by diluting 2 mLof (1+1) HNO3
and 10 mL of (1+1) HCI to 100 mL
with deionized, distilled water (See
Note 6 ) Prepare a sufficient quantity
to be  used to flush the system be-
tween standards and samples

752 The  reagent blank must con-
contain all the reagents and in the
same volumes as used in the  pro-
cessing of the  samples The reagent
blank must be carried through the
complete procedure and contain the
same acid concentration in the final
solution as the sample solution
used for analysis

7.6   In addition to the calibration
standards, an instrument check stan-
dard (3 7), an interference check
sample (3 8) and a quality control
sample (3 9) are also required for the
analyses

761  The instrument check standard
is prepared by  the analyst by com-
bining compatible elements at a con-
centration equivalent to the midpoint
of their respective calibration curves
(See 121 1)

752 The interference check sample
is prepared by  the analyst in the
following manner Select a
representative  sample which contains
minimal concentrations of the
analytes of interest by known  con-
centration of interfering elements that
will provide an adequate test of the
correction factors Spike the sample
with the elements of interest at the
approximate concentration of either
100 /ug/L or 5  times the estimated
 detection limits given in Table 1  (For
 effluent samples of expected high
 concentrations, spike at an
 appropriate level) If the type of
 samples analyzed are varied  a
 synthetically prepared sample may be
 used if the above criteria and intent
 are met A limited supply of a
 synthetic interference check sample
 will be available from the Quality
 Assurance Branch of EMSL-
 Cmcmnati (See 1212)

 753  The quality  control sample
 should be prepared in the same acid
 matrix as the calibration standards
 at a concentration near 1 mg/L and in
 accordance with the instructions
 provided by the supplier The Quality
 Assurance Branch of EMSL-Cmcmnati
 will either supply a  quality control
 sample or information where one of
 equal quality can be procured (See
 1213)

8   Sample handling an
   preservation

8 1   For the determination of trace
elements, contamination and loss are
of prime concern  Dust in the labora-
tory environment  impurities in
reagents and impurities on laboratory
apparatus which the sample contacts
are all sources of potential
contamination Sample containers can
introduce  either positive or negative
errors in the measurement of trace
elements by (a) contributing con-
taminants through leaching or surface
desorption and (b) by depleting
concentrations through adsorption
Thus the collection and treatment of
the sample prior to analysis requires
particular  attention  Laboratory
glassware including the sample bottle
(whether polyethylene, polyproplyene
or FEP-fluorocarbon) should be
thoroughly washed with detergent
and tap water, rinsed with (1+1) nitric
acid, tap water, (1+1) hydrochloric
acid, tap and finally  deionized, distilled
water in that order (See Notes 2 and
3)
NOTE 2 Chromic acid  may be useful to
remove organic deposits from glass-
ware, however, the analyst should be
be cautioned that the glassware must
be thoroughly rinsed with water to
remove the last traces of chromium
This is especially important if chromium
is to be included in the analytical
scheme A commercial product, NOCH-
ROMIX, available from Godax Labor-
atories, 6 Varick St, New York, NY
10013, may be used in place of
chromic acid Chomic acid should not
be used with plastic bottles
NOTES Ifitcanbedocumentedthrough
 an active analytical quality control
 program using spiked samples and re-
 agent blanks, that certain steps m the
 cleaning procedure are not required for
 routine samples, those steps may be
 eliminated from the procedure

 8 2  Before collection of the sample a
 decision must be made as to the type
 of data desired, that is dissolved,
 suspended or total, so that the appro-
 priate preservation and pretreatment
 steps may be accomplished Filtration,
 acid preservation,  etc , are to be per-
 formed at the time the sample is
 collected or as soon as possible
 thereafter

 821   For the determination of dis-
 solved elements the sample must be
 filtered through a 045-yum membrane
 filter as soon as practical after collec-
 tion (Glass or plastic filtering appara-
 tus are recommended to avoid possi-
 ble contamination ) Use the first 50-
 100 mL to rinse the filter flask  Dis-
 card this portion and collect the
 required volume of filtrate Acidify the
 filtrate with (1 +1) HNO3 to a pH of 2
 or less Normally, 3 mL of (1+1) acid
 per liter should be sufficient to pre-
 serve the sample

 822   For the determination  of sus-
 pended elements a measured  volume
 of unpreserved sample must be fil-
 tered through a 045-/t/m membrane
 filter as soon as practical after
 collection The filter plus suspended
 material should be transferred to a
 suitable container for storage  and/or
 shipment  No preservative  is required

 823   For the determination  of total
 or total  recoverable elements, the
 sample  is acidified with (1+1) HNOs
 to pH 2 or less as soon as  possible,
 preferable at the time of collection
 The sample is not filtered before
 processing

 9   Sample Preparation
 9 1  For the determinations of dis-
solved elements,  the filtered,
 preserved sample may often be
analyzed as received  The acid matrix
and concentration of the samples and
calibration standards must  be the
same (See Note 6) If a precipitate
formed upon acidification of the
sample or during transit or storage,  it
must be redissolved before the
analysis by adding additional acid
and/or by heat as described m 9 3

9 2  For the determination of sus-
pended elements, transfer the mem-
brane filter containing the insoluble
material to a 150-mL Griffin beaker
and add 4 mL cone HNOs  Cover the
                                     Metals-24
                           Dec 1982

-------
  beaker with a watch glass and heat
  gently The warn acid will soon dis-
  solve the membrane
    Increase the temperature of the
  hot plate and digest the material
  When the acid has nearly evaporated
  cool the  beaker and watch glass and
  add another 3 mL of cone HIMO3
  Cover and continue heating until the
  digestion is complete generally indi-
  cated by a light colored digestate
  Evaporate to near dryness (2 mL), cool
  add lOmLHCI (1+1) and 15 mL
  deionized distilled water per 100 mL
  dilution and warm the beaker gently
  for 15 mm to dissolve any precipi-
  tated or residue material  Allow to
  cool, wash down the watch glass and
  beaker walls with deionized distilled
  water and filter the sample to remove
  insoluble material that could clog the
  nebulizer  (See Note 4 ) Adjust the
  volume based on the expected con-
  centrations of elements present This
 volume will vary depending on the
  elements to be determined (See Note
  6) The sample is now ready for
 analysis Concentrations so determined
 shall be reported as   suspended
 NOTE 4 In place of filtering, the
 sample after diluting and mixing may
 be centnfuged or allowed to settle by
 gravity overnight  to remove insoluble
 material

 9 3  For the determination of  total
 elements, choose a measured, volume
 of the well mixed acid preserved
 sample appropriate for the expected
 level of elements  and transfer  to a
 Griffin beaker (See Note 5 ) Add 3 mL
 of cone HNO3 Place the beaker on
 a hot plate and evaporate to near dry-
 ness cautiously, making certain that
 the sample does not boil and that no
 area of the bottom of the beaker is
 allowed to go dry  Cool the beaker and
 add another 5 mL portion of cone
 HNO3  Cover the beaker with a watch
 glass and  return to the hot plate
 Increase the temperature of the hot
 plate so that a gentle reflux action
 occurs Continue heating, adding addi-
 tional acid as necessary, until the
 digestion is complete (generally indi-
 cated when the digestate is light
 in color or does not change in appear-
 ance with continued refluxmg ) Again
 evaporate  to near  dryness and  cool
 the beaker Add 10 mL of 1+1 HCI
 and 15 mL of deionized distilled
 water per  100 mL of final solution
 and warm the beaker gently for 15
 mm to dissolve any precipitate or
 residue resulting from evaporation
Allow to cool, wash down the beaker
walls and watch glass with deionized
distilled water and filter the sample to
remove insoluble material that could
  clog the nebulizer (See Note 4 ) Adjust
  the sample to a predetermined volume
  based on the expected concentrations
  of elements present  The sample is
  now ready for analysis (See Note 6)
  Concentrations so determined shall be
  reported as  total
  NOTE 5 If low determinations of
  boron are critical, quartz glassware
  should be use
  NOTE 6 If the sample analysis solution
  has a different acid concentration
  from that given in 9 4, but does not
  introduce  a physical interference or
  affect the  analytical result the same
  calibration standards may be used

 9 4  For the determination of total
 recoverable elements  choose a mea-
 sured volume of a well mixed, acid
 preserved  sample appropriate for  the
 expected level  of elements and trans-
 fer to a Griffin beaker (See Note 5 )
 Add 2 mL  of (1+1) HNO3 and  10 mL
 of (1+1) HCI to the sample and heat
 on a steam bath or hot plate until the
 volume has been reduced to near 25
 mL making certain the sample does
 not boil After this treatment  cool
 the sample and filter to remove inso-
 luble material that could clog the
 nebulizer (See Note 4 ) Adjust the
 volume to 100 mL and mix The sample
 is now ready for analysis  Concentra-
 tions so determined shall be reported
 as  total

 10    Procedure

 101   Set  up instrument with proper
 operating parameters established  m
 6 2 The instrument must  be allowed
 to become  thermally stable before be-
 ginning  This usually requires at least
 30 mm  of  operation prior  to calibra-
 tion

 102   Initiate appropriate  operating
 configuration of computer

 103   Profile and calibrate instru-
 ment  according to instrument
 manufacturer s recommended
 procedures, using the typical mixed
 calibration  standard solutions
 described in 7 4 Flush the system
 with the calibration blank (751)
 between each standard (See Note 7 )
 (The use of the average intensity of
 multiple exposures for both
 standardization and sample analysis
 has been found to reduce random
 error)
 NOTE  7 For  boron concentrations
 greater than 500 jjg/L extended flush
times of 1 to 2 mm  may be required

 104   Before beginning the sample
run  reanalyze the highest  mixed
calibration standard as if it were a
 sample Concentration values obtained
 should not deviate from the actual
 values by more than  5 percent
 (or the established control  limits
 whichever is lower) If they do, follow
 the recommendations of the  instru-
 ment manufacturer to correct for this
 condition

 105  Begin the sample run flushing
 the system with the calibration blank
 solution (751) between each sample
 (See Note 7  ) Analyze the instrument
 check standard (761) and the calibra-
 tion blank (751) each 10 samples

 106  If it has been found that
 method of standard addition are
 required, the following procedure is
 recommended

 10 6 1  The standard addition tech-
 nique (14 2)  involves preparing new
 standards in the sample matrix by
 adding known amounts of standard to
 one or more ahquots of the processed
 sample solution This technique com-
 pensates for a sample constituent that
 enhances or depresses the analyte
 signal thus producing a different slope
 from that of  the calibration standards
 It will not  correct for additive inter-
 ference which causes a baseline shift
 The simplest version of this technique
 is the single-addition method The
 procedure is as  follows Two  identical
 ahquots of the sample solution, each
 of volume Vx, are taken To the
 first (labeled A)  is added a small
 volume Vs of a standard analyte
 solution of concentration cs To the
 second (labeled  B) is added the same
 volume Vs of the solvent The analy-
 tical signals of A and B  are measured
 and corrected for nonanalyte  signals
 The unknown sample concentration
 cx is calculated

           cx =   SBVscs
               (SA - SB) Vx
 where SA and SB are the analytical
 signals (corrected for the blank) of
 solutions A and B  respectively  Vs
 and cs should be chosen so that SA
 is roughly twice SB on the average  It
 is best if Vs is made much less than
 Vx, and thus Cs is much greater than
 cx, to avoid excess dilution of the
 sample matrix If a separation or
 concentration step is used, the
 additions are  best made first and
 carried through the entire procedure
 For the results from this technique to
 be valid, the following limitations
 must be taken into consideration
 1  The analytical curve must be linear
2  The chemical form of the analyte
added must respond the same as the
analyte m the sample
                                     Dec  1982
                                                                 Metals-25

-------
3 The interference effect must be
constant over the working range of
concern
4 The signal must be corrected for
any additive interference

11.  Calculation

11.1  Reagent blanks (7 5 2) should
be subtracted from all samples This is
particularly important for digested
samples requiring large quantities of
acids to complete the digestion

112 If dilutions were performed,
the appropriate factor must be applied
to sample values

113 Data should be rounded to the
thousandth place and all results
should be reported in mg/L up to
three significant figures

12. Quality Control
(Instrumental)

12.1  Check the instrument
standardization by analyzing
appropriate quality control check
standards as follow

12.1.1  Analyze an appropriate
Instrument check standard (761)
containing the elements of interest  at
a frequency of 10% This  check
standard is used to determine
Instrument drift If agreement is not
within 5% of the expected values  or
within the established control limits,
whichever is lower, the analysis is out
of control The analysis should be
terminated,  the problem corrected,
and the instrument recalibrated
  Analyze the calibration blank (751)
at a frequency of 10% The result
should be within the established
control  limits of two standard devia-
tions of the mean value  If not, repeat
the analysis two more times and
average the three results If the
average is not within the control  limit,
terminate the analysis, correct the
problem and recalibrate the
instrument

1212  To verify interelement and
background correction factors analyze
the interference check sample  (7 6  2)
at the beginning, end, and at periodic
Intervals throughout the sample run
Results should fall within the
established control limits of 1 5 times
the standard deviation of the mean
value If not. terminate the analysis,
correct  the problem and recalibrate
the instrument

 12.1,3  A quality control sample
(7 6 3) obtained from an outside
source must first be used for the
initial verification of the calibration
standards A fresh dilution of this
sample shall be anlayzed every week
thereafter to monitor their stability  If
the results are not within 5% of the
true value listed for the control
sample, prepare a new calibration
standard and recalibrate the
instrument  If this does not correct the
problem, prepare a new  stock
standard and a  new calibration
standard and repeat the  calibration

Precision  and  Accuracy

131  In an EPA round  robin phase 1
study, seven laboratories applied the
ICP technique to acid-distilled water
matrices that had been dosed with
various metal concentrates Table 4
lists the true value,  the mean reported
value and the mean % relative
standard deviation

References
1   Wmge  RK  VJ  Peterson  and
VA  Fassel  Inductively Coupled
Plasma-Atomic  Emission
Spectroscopy Prominent Lines   EPA-
600/4-79-017

2   Wmefordner J D  Trace
Analysis Spectroscopic Methods for
Elements,  Chemical Analysis Vol
46, pp 41 -42

3   Handbook for Analytical Quality
Control in Water and Wastewater
Laboratories, EPA-600/4-79-019

4   Garbarmo, J R and Taylor  H E
 An Inductively-Coupled  Plasma
Atomic Emission Spectrometric
Method for Routine Water Quality
Testing  Applied Spectroscopy 33,
No 3(1979)

5    Methods for Chemical Analysis  of
Water and Wastes   EPA-600/4-79-
020

6   Annual Book of ASTM Standards
Part 31

7    Carcinogens - Working With
Carcinogens  Department of Health,
Education and Welfare Public Health
Service, Center for Disease Control,
National Institute for Occupational
Safety and Health Publication No 77-
206, Aug  1977

8    OSHA Safety and Health Stan-
dards  General Industry  (29 CFR
1910), Occupational Safety and Health
Administration OSHA 2206  (Revised
January 1976)

9    Safety in Academic  Chemistry
Laboratories American Chemical So-
ciety Publication Committee on
Chemical Safety 3rd Edition  1979
                                     Metals-26
                                                                Dec 1982

-------
Table 1     Recommended Wavelengths ' and Estimated Instrumental
Detection Limits
Element
Aluminum
Arsenic
Antimony
Barium
Beryllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Potassium
Selenium
Silica (SiOz)
Silver
Sodium _.
Thallium
Vanadium
Zinc
Wavelength, nm
308215
193 696
2O6 833
455 403
313042
249 773
226 502
317933
267716
228 616
324 754
259 940
220 353
279 079
257610
202 030
231 604
766491
196 026
288 158
328 068
588 995
19O 864
292 402
213856
Estimated detection
limit [ig/Lz
45
53
32
2
03
5
4
10
7
7
6
7
42
30
2
8
15
see3
75
58
7
29
40
8
2
  overall acceptance  Other wavelengths may be substituted if they can
  provide the needed sensitivity and are treated with the same corrective
  techniques for spectral interference (See 511)
 zThe estimated instrumental detection limits as shown are taken from
   'Inductively Coupled Plasma-Atomic Emission Spectroscopy-Promment
  Lines  EPA-600/4-79-017 They are given as a guide for an instrumental
  limit The actual method detection limits are sample dependent and may vary
  as the sample matrix varies
 ^Highly dependent on operating conditions and plasma position
                                        '982                  Metals-27

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Table 2    Analyte Concentration Equivalents (mg/L) Arising From Interferents at the 100 mg/L Level

Analvte         Wavelength, nm                                     Interferent

Aluminum
Antimony
Arsenic
Bsnum
Beryl/ium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Selenium
Silicon
Sodium
Thallium
Vanadium
Zinc

308215
206 833
193 696
455403
313042
249 773
226502
317933
267 716
228 616
324 754
259 940
220 353
279 O79
257 610
202 030
231 604
196 026
288 158
588 995
190 864
292 402
213 856
Al Ca
 
047 
13 
	 : 	
 
004 
	 	
 
 
_ _
 
 
077 
 002
0005 
005 
 
023 
	 	
 
030 
	 	
 
Cr

29
044
	
_
	 
	
008

003


	
0 11
001



007


005

Cu Fe
 
 oos
 
	 
 
 032
 003
 OO7
 0003
 0005
 OO03
	 	
	 	
 0/3
 0002
 003
 
 003
 
 
 
 0005
014 
Mg Mn
 021
 

 
 
 
 
007 O04
 004
	 
 
 0 72
 
 025
0002 
 
 
 
 
 
 
 
 
Ni Ti
 
 25
~~ ~~
 
 004
~~ ~~
002 
 003
 
0 03 0 75
 005
~ ~~
 
 007
__
 
 
  '
 
 OOS
	 : 	
 002
023 
V
1 4
0 45
;*
1
 '
005


003
004

002

' 
0 72


	

007
: 	
__

	
 Table 3.    Interferent and Analyte Elemental Concen-
           trations Used for Interference Measurements
           in Table 2
Ana/ytes    (mg/L)
Interferents
(mg/L)
Al
As
B
Ba
Be
Ca
Cd
Co
Cr
Cu
Fe
Mg
Mn
Mo
Na
Ni
Pb
Sb
Se
Si
TI
V
Zn
10
JO
1O
1
1
1
10
1
1
1
1
1
1
JO
10
10
JO
JO
JO
1
JO
1
10
Al
Ca
Cr
Cu
Fe
Mg
Mn
Ni
Ti
V













1000
10OO
200
200
1000
1000
200
200
200
200













                                      Metals-28
                                                                Dec 1982

-------
Table 4



Element
Be
Mn
V
As
Cr
Cu
Fe
Al
Cd
Co
Ni
Pb
Zn
Se
ICP Precision and Accuracy Data
Sample # /

True
Value
M/L
750
350
750
200
150
250
600
700
50
500
250
250
200
40
Mean
Reported
Value
fjg/L
733
345
749
208
149
235
594
, 696
48
512
245
236
20 1
32

Mean
Percent
PSD
62
27
18
75
38
51
30
56
12
10
58
16
56
21 9

True
Value
Pff/L
20
15
70
22
JO
11
20
60
25
20
30
24
16
6
Sample #2
Mean
Reported
Value
H9/L
20
15
69
19
10
11
19
62
29
20
28
30
19
85


Mean
Percent
RSD
98
67
29
23
18
40
15
33
16
4 1
11
32
45
42


True
Value
V9/L
180
100
170
60
50
70
180,
160
14
120
60
80
80
10
Sample #3
Mean
Reported
Value
Pff/i-
176
99
169
63
50
67
178
161
13
108
55
80
82
85
-
.
Mean
Percent
RSD
52
33
1 1
17
33
79
60
13
16
21
14
14
94
83
Dec 1982
                            Meta/s-29

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                                    ALUMINUM

               Method  202.1 (Atomic Absorption, direct aspiration)

                                                         STORET NO.  Total  01105
                                                                      Dissolved  01106
                                                                    Suspended  01107

 Optimum Concentration Range:   5-50 mg/1 using a wavelength of 309 3 nm
 Sensitivity:            1 mg/1
 Detection Limit       0 1 mg/1

 Preparation of Standard Solution
      1    Stock Solution Carefully weigh 1 000 gram of aluminum metal (analytical reagent
           grade) Add 15 ml of cone HC1 and 5 ml cone HNO3 to the metal, cover the beaker and
           warm gently When solution is complete, transfer quantitatively to a 1 liter volumetric
           flask and make up to volume with deiomzed distilled water 1 ml = 1 mg Al (1000 mg/1)
      2    Potassium Chloride Solution  Dissolve 95 g potassium chloride  (KC1) in deiomzed
           distilled water and make up to 1 liter
      3    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis  The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing To each 100 ml of standard and sample alike add 2 0 ml potassium chloride
           solution

 Sample Preservation
      1     For sample handling and preservation, see part 4,1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     The procedures for the preparation of the sample as given in part 4 1 1 through 4 1 4 of
           the Atomic Absorption  Methods section of this  manual have  been found to be
           satisfactory

 Instrumental Parameters (General)
      1     Aluminum hollow cathode lamp
      2     Wavelength 309 3 nm
      3     Fuel Acetylene
      4     Oxidant Nitrous oxide


Approved for NPDES
Issued 1971
Editorial revision  1974 and 1978

                                        202.1-1

-------
     5.   Type of flame Fuel rich

Analysis Procedure
     1    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual

Interferences
     1    Aluminum is partially ionized in the nitrous oxide-acetylene flame This problem may be
          controlled by the addition of an alkali metal (potassium, 1000 ug/ml) to both sample and
          standard solutions
                                                                                  i     *
Notes
     1    The following lines may also be used
          308 2 nm Relative Sensitivity 1
          396 2 nm Relative Sensitivity 2
          394 4 nm Relative Sensitivity 2 5
     2    Data to be entered into STORET must be reported as ug/1
     3    For concentrations of aluminum below 0 3 mg/1, the furnace procedure (Method 202 2)
          is recommended
     4    The Enochrome cyanme R colonmetnc method may also be used The optimum range
          for this method lies between 20 and 300 ug/1 (Standard Methods, 14th Edition, p  171 )
          In  the absence of fluorides  and  complex phosphates,  a detection  limit of 6 ug/1 is
          possible

Precision and Accuracy
     1    An Intel-laboratory study on trace metal analyses by atomic absorption was conducted by
          the Quality Assurance  and Laboratory Evaluation Branch of EMSL Six synthetic
          concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
          manganese, lead and zinc were added to natural water samples  The statistical results for
          aluminum were as follows
 Number        True values          Mean Value          Deviation           Accuracy as
 of Labs          ug/liter             ug/liter  r           ug/liter               %Bias
  38             1205                 1281                 299                   63
  38             1004                 1003                 391                  -01
  37              500                 463                 202                  -74
  37              625                 582                 272                  -68
  22              35                  96                 108                 175
  21              15                 109                 168                 626
                                          202 1-2

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                                    ALUMINUM

              Method 202.2 (Atomic  Absorption,  furnace  technique)
                                                        STORET NO. Total 01105
                                                                     Dissolved 01106
     ,    ,                               ,                           Suspended 01107
     tf
Optimum Concentration Range:   20-200 ug/1
Detection Limit:      3 ug/1

Preparation of Standard Solution
      1     Stock solution  Prepare as described under "direct aspiration method"
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
     3     The calibration standard should be diluted to contain 0 5 % (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as described under "direct aspiration method"  Sample solutions for analysis
           should contain 0 5% (v/v) HNO3

Instrument Parameters (General)
     1     Drying Time and Temp   30 sec-125C
     2     Ashing Time and Temp   30sec-1300C
     3     Atomizing Time and Temp    10 sec-2700C
     4     Purge Gas Atmmosphere  Argon
     5     Wavelength   309 3 nm
     6     Other operating parameters should be  set as  specified by the particular instrument
           manufacturer                                          f

Analysis Procedure
     1     For the analysis procedure and the caculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued  1978
                                       202 2-1

-------
Notes
      1.    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite
     2     Background correction may be required if the sample contains high dissolved solids
     3     It has been reported that chloride ion and that nitrogen used as a purge gas suppress the
           aluminum signal Therefore the use of halide acids and nitrogen as a purge gas should be
           avoided
     4     For every sample matrix analyzed,  verification is necessary to determine that method of
           standard addition is not required  (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         202 2-2

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                                    ANTIMONY

               Method 204.1 (Atomic  absorption, direct aspiration)

                                                        STORET NO. Total 01097
                                                                     Dissolved 01095
                                                                    Suspended 01096

Optimum Concentration Range:   1-40 mg/1 using a wavelength of 217 6 nm
Sensitivity:      0 5 mg/1
Detection Limit:      0 2 mg/1

Preparation of Standard Solution
      1     Stock Solution  Carefully  weigh  2 7426  g of  antimony  potassium tartrate
           K(SbO)C4H4O6 ^H2O (analytical reagent grade) and dissolve in deiomzed distilled
           water Dilute to 1 liter with deiomzed distilled water 1 ml = 1 mg Sb (1000 mg//l)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The procedures for preparation of the sample as given in parts 411 through 414 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
      1     Antimony hollow cathode lamp
     2     Wavelength 2176 nm
     3     Fuel Acetylene
     4     Oxidant Air
     5    Type of flame Fuel lean

Analysis Procedure
     1    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual


Approved for NPDES
Issued 1974
Editorial  revision 1978

                                       204 1-1

-------
Interferences
      1.    In the presence of lead (1000 mg/1), a spectral interference may occur at the 217 6 nm
           resonance line In this case the 2311 nm antimony line should be used
      2     Increasing acid concentrations decrease antimony absorption To avoid this effect, the
           acid concentration m the samples and in the standards should be matched

Notes
      1     Data to be entered into STORET must be reported as ug/1
      2     For concentrations of antimony below 0 35 mg/1, the furnace procedure (Method 204 2)
           is recommended

Precision and Accuracy
      1     In a single laboratory (EMSL), using a mixed industrial-domestic waste effluent at
           concentrations of 5 0 and 15 mg Sb/1, the standard deviations were 0 08 and 0 1,
           respectively Recoveries at these levels were 96% and 97%, respectively
                                         204 1-2

-------
                                    ANTIMONY
              Method 204.2 (Atomic  Absorption, furnace technique)
                                                        STORET  NO. Total 01097
                                                                     Dissolved 01095
                                                                    Suspended 01096
Optimum Concentration Range*   20-300 ug/1
Detection Limit:       3 ug/1
Preparation of Standard Solution
     1    Stock solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 0 2% (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    The procedures for preparation of the sample as given in parts 411 thru 4 1 3 of the
          Atomic Absorption Methods section of this manual should be followed including the
          addition of sufficient  1 1 HC1 to dissolve the digested residue for the analysis of
          suspended or total antimony The sample solutions used for analysis should contain 2%
          (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp  30 sec-125C
     2    Ashing Time and Temp  30sec-800C
     3    Atomizing Time and Temp    10 sec-2700C
     4    Purge Gas Atmosphere   Argon
     5    Wavelength  217 6 nm
     6    Other operating parameters should be set as specified  by the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual
Approved for NPDES
Issued 1978
                                        204 2-1

-------
Notes
     1     1 he above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
     2     The use of background correction is recommended
     3     Nitrogen may also be used as the purge gas
     4     If chloride  concentration presents  a matrix problem or causes  a loss previous to
           atomization, add an excess of 5 mg of ammonium nitrate to the furnace and ash using a
           ramp accessory or with incremental steps until the recommended ashing temperature is
           reached
     5     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     6     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     7     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         204 2-2

-------
                                      ARSENIC

              Method 206.2 (Atomic  Absorption, furnace technique)

                                                         STORET NO. Total 01002
                                                                      Dissolved 01000
                                                                    Suspended 01001
Optimum Concentration Range: 5-100 ug/1
Detection Limit: 1 ug/1

Preparation of Standard Solution
     1     Stock solution Dissolve 1 320 g of arsenic tnoxide, As203 (analytical reagent grade) in
           100 ml of deiomzed distilled water containing 4 g NaOH Acidify the solution with 20 ml
           cone HNO3 and dilute to 1 liter 1 ml = 1 mg As (1000 mg/1)

     2     Nickel Nitrate Solution, 5% Dissolve 24 780 g of ACS reagent grade Ni(NO3)26H2O in
           deiomzed distilled water and make up to 100ml

     3     Nickel Nitrate Solution, 1%  Dilute 20 ml of the 5% nickel nitrate to 100 ml with
           deiomzed distilled water

     4     Working Arsenic Solution Prepare dilutions of the  stock solution to be used as
           calibration standards at the time of analysis Withdraw appropriate  ahquots of the stock
           solution, add 1 ml of cone HNO3, 2ml of 30% H2O2 and 2ml of the 5% nickel nitrate
           solution  Dilute to 100 ml with deiomzed distilled water

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     Transfer 100 ml of well-mixed sample to a 250 ml Griffin beaker, add 2 ml of 30% H2O2
           and sufficient cone  HNO3 to result in an acid concentration of 1 %(v/v)  Heat for 1 hour
           at 95C or until the volume is slightly less than 50 ml

     2     Cool and bring back to 50 ml with deiomzed distilled water

     3     Pipet 5 ml of this digested solution into a 10-ml volumetric flask,  add  1 ml of the 1%
           nickel nitrate solution and dilute to 10 ml with deiomzed distilled water The sample is
           now ready for injection into the furnace
Approved for  NPDES  and SDWA
Issued 1978

                                         206 2-1

-------
          NOTE: If solubilization or digestion is not required, adjust the HNO3 concentration of
          the sample to 1% (v/v) and add 2 ml of 30%H2O2 and 2 ml of 5% nickel nitrate to each
          100 ml of sample  The volume of the calibration standard should be adjusted with
          deiomzed distilled water to match the volume change of the sample

Instrument Parameters (General)
      1.   Drying Time and Temp 30sec-125C
      2    Ashing Time and Temp 30sec-1100C
      3    Atomizing Time and Temp 10sec-2700C
      4    Purge Gas Atmosphere Argon
      5.   Wavelength 193 7 nm
      6    Other operating parameters should be set as specified by the particular instrument
          manufacturer
                                                   
Analysis Procedure
      1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual

Notes
      1    The above concentration values and instrument conditions are for a Perkin-Elmer HGA-
          2100, based on the use of a 20 ul injection, purge gas interrupt and non-pyrolytic
          graphite  Smaller size furnace devices or those employing faster rates of atomization can
          be operated using lower atomization  temperatures for shorter time periods  than the
          above recommended settings
      2    The use of background correction is recommended
      3    For every sample matrix analyzed, verification is necessary to determine that method of
          standard addition is not required (see part 5 2 1 of the Atomic Absorption  Methods
          section of this manual)
      4    If method of standard addition is required, follow the procedure given earlier m part 8 5
          of the Atomic Absorption Methods section of this manual
      5.   For quality  control requirements  and optional recommendations for use in  drinking
          water analyses, see part 10 of the Atomic Absorption Methods section of this manual
      6.   Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1    In  a single  laboratory (EMSL),  using a mixed industrial-domestic waste  effluent
          containing 15 ug/1 and spiked with concentrations of 2, 10 and 25 ug/1, recoveries of
          85%, 90% and 88% were obtained respectively The relative standard deviation at these
          concentrations levels were 88%,  & 2%, 5 4% and 8 7%, respectively
      2    In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
          of 20, 50 and  100  ug As/1,  the standard  deviations  were 07, 11 and 16
          respectively  Recoveries at these levels were 105%, 106% and 101%, respectively
                                        206 2-2

-------
                                      ARSENIC

               Method 206.3 (Atomic  Absorptiongaseous  hydride)
                                                         STORET NO.  Total 01002
                                                                     Dissolved 01000
                                                                    Suspended 01001
      Scope and Application
      1 1   The  gaseous  hydride  method  determines inorganic arsenic  when  present  in
           concentrations at or above 2 ug/1  The method is applicable to drinking water and most
           fresh and saline waters in the absence of high concentrations of chromium, cobalt,
           copper, mercury, molybdenum, nickel and silver
      Summary of Method
      2 1   Arsenic in the sample is first reduced to the tnvalent form using SnCl2 and converted to
           arsine, AsH3, using zinc metal The gaseous hydride is swept into an argon-hydrogen
           flame of an atomic absorption spectrophotometer The working range of the method is
           2-20 ug/1 The 193 7 nm wavelength line is used
      Comments
      3 1   In analyzing drinking water and most surface and ground waters, interferences are rarely
           encountered Industrial waste samples should be spiked with a known amount of arsenic
           to establish adequate recovery
      3 2   Organic forms of arsenic must be converted to inorganic compounds and organic matter
           must be oxidized before beginning the analysis The oxidation procedure given  in
           Method 206 5 (Standard Methods, 14th Edition, Method 404B, p 285, Procedure 4 a)
           has been found suitable
      3 3   For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual
      3 4   For quality control requirements  and optional recommendations for  use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
      3 5   Data to be entered into STORET must be reported as ug/1
      Precision and Accuracy
      4 1   Ten replicate solutions of o-arsemhc acid at the 5,10 and 20 ug/1 level were analyzed by
           a single laboratory Standard deviations were  03, 09 and 1 1 with recoveries of 94,
           93  and 85%,  respectively (Caldwell, J  S, Lishka, R J, and McFarren,  E  F,
           "Evaluation of a Low Cost Arsenic and Selenium Determination at Microgram per Liter
           Levels", JAWWA , vol 65, p 731, Nov , 1973 )
Approved for NPDES and SDWA
Issued  1974
                                        2063-1

-------
5.    References
     5 1,   Except for the perchloric acid step, the procedure to be used for this determination is
           found m Standard Methods for  the  Examination of Water  and Wastewater,  14th
           Edition, p!59, Method 301 A(VII),(1975)
                                          206 3-2

-------
                                      ARSENIC ,
 o                                                               i
                     Method 206.4 (Spectrophotometric-SDDC)

                                                                STORET  NO.  01002
                                                          Inorganic, Dissolved  00095
                                                               Inorganic, Total  00997
                                                         Inorganic, Suspended  00996

1    Scope and Application
     1 1   The silver diethyldithiocarbamate method determines inorganic arsenic when present m
           concentrations at or above 10 ug/1 The method is applicable to drinking water and most
           fresh and saline waters in the absence of high concentrations  of chromium,  cobalt,
           copper, mercury, molybdenum, nickel, and silver Domestic and industrial wastes may
           also be analyzed after digestion (see 3 3)
     1 2   Difficulties may be encountered with certain industrial waste materials containing
           volatile substances High sulfur content of wastes may exceed removal capacity of the
           lead acetate scrubber
2    Summary of Method
     2 1   Arsenic in the sample is reduced to arsme, AsH3, in  acid  solution in a hydrogen
           generator The arsme is passed through a scrubber to remove sulfide and is absorbed in a
           solution of silver diethyldithiocarbamate dissolved  in pyndine The red  complex thus
           formed is measured in a spectrophotometer at 535 nm
3    Comments
     31   In analyzing drinking water and most surface and ground waters, interferences are rarely
           encountered Industrial waste samples should be spiked with a known amount of arsenic
           to establish adequate recovery
     32   It is essential that the system be airtight during evolution of the arsme, to avoid losses
     33   If concentration of the sample and/or oxidation of any organic matter is required, refer
           to Method 206 5 [Standard Methods, 14th Edition, Method 404B, p 284,  Procedure 4 a
           (1975)]  For sample handling and preservation, see part 4 1 of the Atomic Absorption
           Methods section of this manual
           331  Since nitric acid gives  a negative interference in this test,  use sulfunc acid as  a
                preservative if only inorganic arsenic is being measured
     3 4   1-Ephedrme  in chloroform has  been found to  be a suitable  solvent for silver
           diethyldithiocarbamate if the analyst finds the odor of pyndine objectionable [Anal
           Chem 45, 1786 (1973)]
     3 5   For quality control requirements and optional recommendations for use in drinking
           water analyses, see part  10 of the Atomic Absorption Methods section of this manual


Approved for  NPDES and SDWA
Issued  1971
Editorial revision 1974

                                         206 4-1

-------
4.    Precision and Accuracy
     41   In a round-robm study reported by Standard Methods a synthetic unknown sample
           containing 40 ug/1, as As, with other metals was analyzed in 46 laboratories Relative
           standard deviation was 138% and relative error was 0%
5.    Reference
     5 1   The procedure to be used for this determination is found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 283,
           Method 404A (1975)
                                         206 4-2

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                                      ARSENIC

            Method  206.5   (Sample Digestion Prior  to Total  Arsenic
              Analysis by Silver  Diethyldithiocarbamate  or Hydride
                                      Procedures)

      Scope and Application
      1 1   Both the silver diethyldithiocarbamate spectrophotometric method and the AA hydride
           procedure measure inorganic arsenic Therefore, if either of these procedures are being
           employed for the purpose of measuring total arsenic  (inorganic  plus organic), all
           organically bound arsenic must first be converted to  an inorganic  form prior to the
           analytical determination This may be accomplished with H2SO4-HNO3
      Procedure
      21   To a suitable sample containing from 2 to 30 ug of arsenic, add 7 ml (1 +1) H2SO4 and 5
           ml cone HNO3  Evaporate the sample to SO3 fumes Caution  If the  sample chars, stop
           the digestion immediately,  cool and add additional cone HNO3 Continue digestion
           adding additional cone HNO3 as necessary
      22   If the sample remains colorless, or straw-yellow during evolution of SO3 fumes, the
           digestion is complete
      2 3   Cool the digested sample, add about 25 ml  distilled water, and again evaporate to SO3
           fumes to expel oxides of nitrogen
      2 4   The sample  is now ready for analysis using either the hydride or spectrophotometric
           procedure
      Interferences
      3 1   All traces of nitric acid must be removed before either the spectrophotometric or the
           hydride procedures are applied Oxides of  nitrogen should be expelled by taking the
           sample to fumes of SO3
      Notes
      4 1   The digestion step may be carried out in a flask on a hot-plate or in a Kjeldahl apparatus
           This digestion step may also be used, in effect, to concentrate the sample, inasmuch as
           any size volume may be processed

                                      Bibliography

      Standard Methods for the Examination of Water and Wastewater, p285, method 404B, step 4a,
      14th Edition (1975)
Approved for NPDES  and SDWA
Issued 1978
                                        206 5-1

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                                      BARIUM

               Method 208.1  (Atomic Absorption,  direct aspiration)

                                                        STORET  NO. Total 01007
                                                                     Dissolved 01005
                                                                    Suspended 01006

Optimum Concentration Range;   1-20 mg/1 using a wavelength of 553 6 nm
Sensitivity:     0 4 mg/1
Detection Limit:     0 1 mg/1

Preparation of Standard Solution
     1     Stock Solution Dissolve  1 7787 g barium chloride (BaCl22H2O, analytical reagent
           grade) in deiomzed distilled water and dilute to 1 liter 1 ml =  1 mg Ba (1000 mg/1)
     2     Potassium chloride solution  Dissolve 95 g potassium chloride, KC1, in deiomzed
           distilled water and make up to 1 liter
     3     Prepare dilutions of the stock barium solution to be used as calibration standards at the
           time of analysis To each 100 ml of standard and sample alike add 2 0 ml potassium
           chloride solution The calibration standards should be prepared using the same type of
           acid and the same concentration as will result in the sample to be analyzed either directly
           or after processing

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The procedures for preparation of the sample as given in parts 411 through 414 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1     Barium hollow cathode lamp
     2     Wavelength 553 6 nm
     3     Fuel Acetylene
     4     Oxidant Nitrous oxide
     5     Type of flame Fuel rich
Approved for NPDES and  SDWA
Issued  1974
                                        208 1-1

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Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual

Interferences
      1     The use of a nitrous oxide-acetylene flame virtually eliminates chemical interference,
           however, barium is easily ionized in this flame and potassium must be added (1000 mg/1)
           to standards and samples alike to control this effect
      2     If the nitrous oxide flame is not available and acetylene-air is used, phosphate, silicon and
           aluminum will severely depress the barium absorbance This may be overcome by the
           addition of 2000 mg/1 lanthanum

Notes
      1     Data to be entered into STORET must be reported as ug/1
      2     For concentrations of barium below 0 2 mg/1, the furnace procedure (Method 208 2) is
           recommended                 '
      3     For quality control requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual

Precision and Accuracy
      1     In  a single laboratory (EMSL), using  a  mixed industrial-domestic waste effluent at
           concentrations  of 040 and 20  mg  Ba/1, the  standard  deviations were  0043
           and 0 13, respectively Recovereis at these levels were 94% and 113%, respectively
      2     In  a round-robin study reported by Standard Methods (13th Edition, p215, method
           129A,   1971),  three  synthetic samples  containing barium  were  analyzed  by  13
           laboratories At concentrations of 500, 1000 and 5000 ug Ba/1, the reported standard
           deviations  were 50, 89  and 185  ug, respectively  The relative error at these
           concentrations was 8 6%, 2 7% and 1 4%, respectively
                                         208 1-2

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                                      BARIUM

              Method  208.2 (Atomic  Absorption, furnace technique)

                                                                STORET NO.  01007
                                                                     Dissolved  01005
                                                                    Suspended  01006
 Optimum Concentration Range:   10-200 ug/1
 Detection Limit:      2 ug/1

 Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to used for "standard additions"
      3     The calibration standard should be diluted to contain 0 5 % (v/v) HNO3

 Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     Prepare as described under "direct aspiration method"  Sample solutions for analysis
           should contain 0 5% (v/v) HNO3

 Instrument Parameters (General)
      1     Drying Time and Temp    30sec-125C
      2     Ashing Time and Temp    30sec-1200C
      3     Atomizing Time and Temp   10 sec-2800C
      4     Purge Gas Atmosphere   Argon
      5     Wavelength    553 6 nm
      6     Other  operating parameters should be set as specified  by  the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based  on the use of a 20 ul injection, continuous  flow purge gas and pyrolytic
           graphite

Approved for NPDES  and SDWA
Issued 1978

                                        208 2-1

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     2     The use of hahde acid should be avoided
     3     Because of possible chemical interaction, nitrogen should not be used as a purge gas
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1  of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6     For quality control requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
     7     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1.    In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
           of 500 and 1000 ug Ba/1, the standard deviations were 25 and 2 2 ug, respectively
           Recoveries at these levels were 96% and 102%, respectively A dilution of 1 10 was
           required to bring the spikes within the analytical range of the method
                                         2082-2

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                                    BERYLLIUM

              Methods  210.1 (Atomic  Absorption, direct aspiration)

                                                         STORET NO.  Total 01012
                                                                     Dissolved 01010
                                                                    Suspended 01011

Optimum Concentration Range:   0 05-2 mg/1 using a wavelength of 234 9 nm
Sensitivity:      0 025 mg/1
Detection Limit:       0 005 mg/1

Preparation of Standard Solution
      1    Stock  solution  Dissolve 19 6558 g beryllium sulfate, BeSO4H2O,  in  deionized
          distilled water containing 2 ml cone nitric acid and dilute to 1 liter 1 ml = 1 mg Be
          (1000 mg/1)
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis The calibration standards should be prepared using the same type of acid and at
          the same concentration as will result in the sample to be analyzed either directly or after
          processing
Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    The procedures for preparation of the sample as given in parts 411 through 414 of the
          Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1    Beryllium hollow cathode lamp
     2    Wavelength 234 9 nm
     3    Fuel Acetylene
     4    Oxidant Nitrous oxide
     5    Type of flame Fuel rich

Analysis Procedure
     1    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual
Approved for NPDES
Issued  1974
                                        210 1-1

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Interferences
      1     Sodium and silicon at concentrations m excess of 1000 mg/1 have been found to severely
           depress the beryllium absorbance
      2     Bicarbonate ion is reported to interfere, however, its effect is eliminated when samples
           are acidified to a pH of 1 5
      3.    Aluminum at concentrations of 500 ug/1 is  reported to depress the  sensitivity of
           beryllium [Spectrochim Acta 22,1325 (1966)]

Notes
      1.    Data to be entered into STORET must be reported as ug/1
      2     The "aluminon colonmetnc method"  may also be  used (Standard  Methods,  14th
           Edition, p 177) The minimum detectable concentration by this method is 5 ug/1
      3     For concentrations of beryllium below 0 02 mg/1, the furnace procedure (Method 2102)
           is recommended

Precision and Accuracy
      1.    In a single laboratory (EMSL), using a mixed industrial-domestic waste effluent at
           concentrations of 0 01, 0 05 and 0 25 mg Be/1, the standard deviations were  0 001,
           0 001 and 0 002, respectively Recoveries at these levels were 100%, 98% and 97%,
           respectively
                                         210 1-2

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                                    BERYLLIUM
                                             i               I
               Method 210.2 (Atomic Absorption,  furnace  technique)

                                                                STORET NO. 01012
                                                                      Dissolved 01010
                                                                     Suspended 01011
 Optimum Concentration Range:    1-30 ug/1
 Detection Limit      0 2 ug/1

 Preparation of Standard Solution
      1    Stock solution- Prepare as described under "direct aspiration method"
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3    The calibration standard should be diluted to contain 05% (v/v) HNO3

 Sample Preservation
      1    For sample handling and  preservation, see part 4 1 of the Atomic Absorption Methods
         1  section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain 05% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp   30sec-125C
      2    Ashing Time and Temp   30sec-1000C
      3    Atomizing Time and Temp  10 sec-2800C
      4    Purge Gas Atmosphere   Argon
      5    Wavelength   234 9 nm
      6    The operating parameters should be set as specified by the particular  instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation see "Furnace Procedure" part 9 3 of the
           Atomic Absorption methods section of this manual

Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
          graphite  Smaller size furnace devices or those employing faster rates of atomization can

Approved for  NPDES
Issued 1978

                                        210 2-1

-------
          be operated using lower atomization temperatures for shorter time periods than the
          above recommended settings
     2.   The use of background correction is recommended
     3    Because of possible chemical interaction and reported lower sensitivity, nitrogen should
          not be used as the purge gas
     4    For every sample matrix analyzed, verification is necessary to determine that method of
          standard addition  is not required (see part 5 2 1 of the Atomic Absorption Methods
          section of this manual)
     5    If method of standard addition is required, follow the procedure given earlier in part 8 5
          of the Atomic Absorption Methods section of this manual
     6    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1    Precision and Accuracy data are not available at this time
                                          210 2-2

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                                       BORON


                      Method 212.3  (Colorimetric, Curcumin)


                                                         STORET NO. Total 01022
                                                                      Dissolved 01020
                                                                     Suspended 01021

      Scope and Application
      1 1   This  colonmetnc method finds maximum utility for waters whose boron content is
           below 1 mg/1
      1 2   The optimum range of the method on undiluted or unconcentrated samples is 0 1-1 0
           mg/1 of boron
      1 3   This  method is  applicable to drinking, and surface waters, domestic and industrial
           wastes
      Summary of Method
      2 1   When a sample of water containing boron is acidified and evaporated in the presence of
           curcumm, a red-colored product called rosocyanine is formed The rosocyamne is taken
           up in a suitable solvent, and the red color is compared with standards photometrically
      Comments
      3 1   Nitrate nitrogen concentrations above 20 mg/1 interfere
      3 2   Significantly high results are possible when the total of calcium and magnesium hardness
           exceeds 100 mg/1 as CaCO3  Passing the sample through a cation exchange resin
           eliminates this problem
      3 3   Close control of such variables as volumes and concentrations of reagents, as well as time
           and temperature of drying, must be exercised for maximum accuracy
      3 4   Data to be entered into STORET must be reported as ug/1
      Precision and Accuracy
      4 1   A synthetic  sample prepared by the Analytical Reference Service, PHS, containing  240
           ug/1  B, 40  ug/1 As, 250 ug/1 Be, 20 ug/1 Se, and 6 ug/1  V in distilled water, was
           analyzed by the curcumm method with a relative  standard deviation of 22 8% and a
           relative error of 0% in 30 laboratories
      Reference
      5 1   The procedure to be used for this determination is found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 287,
           Method 405 A (1975)
Approved for NPDES
Issued  1974
                                        2123-1

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                                      CADMIUM

               Method 213.1  (Atomic Absorption,  direct aspiration)

                                                         STORET  NO. Total 01027
                                                                      Dissolved 01025
                                                                     Suspended 01026

 Optimum Concentration Range:    0 05-2 mg/1 using a wavelength of 228 8 nm
 Sensitivity:     0 025 mg/1
 Detection Limit.      0 005 mg/1

 Preparation of Standard Solution
      1    Stock Solution Carefully weigh 2 282 g of cadmium sulfate (3CdSO48H2O, analytical
           reagent grade) and  dissolve in deionized distilled water make up to 1 liter with
           deionized distilled water 1 ml = 1 mg Cd (1000 mg/1)
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing
 Sample Preservation
      1    For sample handling and preservation, see part 4  1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    The procedures for preparation of the sample as given in parts 4 1 1 through 414 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

 Instrumental Parameters (General)
      1    Cadmium hollow cathode lamp
      2    Wavelength 228 8 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Oxidizing

 Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
Approved for NPDES  and SDWA
Issued 1971
Editorial revision 1974

                                        213 1-1

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Notes
     1     For levels of cadmium below 20 ug/1, either the Special Extraction Procedure given in
           Part 9 2 of the Atomic Absorption methods section as the furnace technique, Method
           213 2 is recommended
     2     Data to be entered into STORET must be reported as\ug/l
     3     For quality control requirements  and  optional recommendations for use in  drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual

Precision and Accuracy
     1     An mterlaboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance and Laboratory Evaluation Branch of EMSL  Six  synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples The statistical results for
           cadmium were as follows

                                                         Standard
 Number        True Values         Mean Value           Deviation           Accuracy as
 of Labs           ug/liter              ug/liter              ug/liter              %  Bias

  74              71                  70                  21                  -22
  73              78                  74                   18                  -5 /
  63              14                  168                 110                198
  68              18                  183                 103                 19
  55               14                  33                 50                135
  51               28                  29                 28                 47
                                         213 1-2

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                                     CADMIUM

               Method 213.2  (Atomic Absorption, furnace technique)

                                                                STORET NO.  01027
                                                                     Dissolved  01025
                                                                    Suspended  01026
 Optimum Concentration Range:   05-10 ug/1
 Detection Limit:      0 1 ug/1

 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
      2    Ammonium Phosphate solution (40%)  Dissolve 40 grams of ammonium phosphate,
           (NH4)2HPO4 (analytical reagent grade) in deiomzed distilled water and dilute to 100 ml
      3    Prepare dilutions of the stock cadmium solution to be used as calibration standards at the
           time of analysis  To each 100 ml of standard and sample alike add 2 0 ml  of the
           ammonium phosphate solution The calibration standards should be prepared to contain
           0 5% (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain 05% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp  30 sec-125C
      2    Ashing Time and Temp  30 sec-500C
      3    Atomizing Time and Temp   10 sec-1900C
      4    Purge Gas Atmosphere  Argon
      5    Wavelength  228 8 nm
      6    Other operating parameters should be set as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES and SDWA
Issued  1978

                                        213 2-1

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Notes
     1    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
          2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
          graphite Smaller size furnace devices or those employing faster rates of atomization can
          be operated using lower atomization temperatures for shorter tune periods than the
          above recommended settings
     2    The use of background correction is recommended
     3.   Contamination from the work area is critical in cadmium  analysis Use of pipet tips
                                                                     j      ill     '* I
           which are free of cadmium is  of particular importance (See part 5 2 9 of the Atomic
          Absorption Methods section of this manual)
     4    For every sample matrix analyzed, verification is necessary to determine that method of
          standard addition is not required (see part 52 I of the Atomic Absorption Methods
          section of this manual)
     5    If method of standard addition  is required, follow the procedure given earlier in part 8 5
          of the Atomic Absorption Methods section of this manual
     6    For quality control requirements and optional recommendations for use in drinking
          water analyses, see part 10 of the Atomic Absorption Methods section of this manual
     7    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1    In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
          of 2 5, 50 and 10 0 ug Cd/1,  the standard deviations were 0 10, 016 and 0 33,
          respectively Recoveries at these levels were 96%, 99% and 98%, respectively
                                         213 2-2

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                                      CALCIUM
                                                                        s
               Method  215.1  (Atomic Absorption, direct aspiration)

                                                          STORET NO.  Total  00916
                                                                      Dissolved  00915

 Optimum Concentration Range:   0 2-7 mg/i using a wavelength,of 422 7 nm
 Sensitivity:     0 08 mg/1
 Detection Limit:      001 mg/1

 Preparation of Standard Solution
    ,  1    Stock Solution  Suspend 1 250 g of CaCO3 (analytical reagent grade), dried at 180C for 1
           hour before weighing,  in deiomzed distilled water and  dissolve  cautiously  with a
           minimum of dilute HC1 Dilute to 1000 ml with, deiomzed distilled water 1 ml = 05
           mgCa (500 mg/1)
      2    Lanthanum chloride solution Dissolve 29 g of La2O3, slowly and in small portions, in
           250 ml cone HC1 (Caution  Reaction is violent) and dilute to 500 ml with deiomzed
           distilled water
      3    Prepare dilutions of the stock calcium solutions to be used as calibration standards at the
           time of analysis To each 10 ml volume of calibration standard and sample alike add 1 0
           ml of the lanthanum chloride solution, i e, 20 ml of standard or sample + 2 ml LaCl3 =
           22ml

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    For the analysis of total calcium in domestic and industrial effluents, the procedures for
           the  determination of total metals as given in parts 413 and 4 1 4 of the Atomic
           Absorption Methods section of this manual have been found to be satisfactory
      2    For ambient waters, a representative aliquot of a well-mixed sample may be used directly
           for analysis If suspended solids are present in sufficient amounts to clog the nebulizer,
           the sample may be allowed to settle and the supernatant liquid analyzed directly

Instrumental Parameters (General)
      1     Calcium hollow cathode lamp
      2    Wavelength 422 7 nm
Approved for NPDES
Issued 1971
Editorial revision 1974

                                         215 1-1

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     3     Fuel Acetylene
     4.    Oxidant Air
     5     Type of flame Reducing

Analysis Procedure
     1.    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual

Notes
     1     Phosphate, sulfate and aluminum interfere but are masked by the addition of lanthanum
           Since low calcium values result if the pH of the sample is above 7, both standards and
           samples are prepared in dilute hydrochloric acid solution Concentrations of magnesium
           greater than 1000 mg/1 also cause low calcium values Concentrations of up to 500 mg/1
           each of sodium, potassium and nitrate cause no interference
     2     Anionic chemical interferences can be expected if lanthanum is not used in samples and
           standards
     3     The nitrous oxide-acetylene flame will provide two to five times greater sensitivity and
           freedom from chemical interferences lomzation interferences should be  controlled by
           adding a large amount of alkali to the sample and standards The analysis appears to be
           free from chemical  suppressions  in  the nitrous  oxide-acetylene  flame  (Atomic
           Absorption Newsletter 14,29 [1975])
     4     The 239 9 nm line may also be used This line has a relative sensitivity of 120
     5.    Data to be entered into STORET must be reported as mg/1
     6     The EDTA titnmetnc method  may also be used (Standard Methods, 14th  Edition, p
           189)

Precision and Accuracy
     1     In a single laboratory (EMSL), using distilled water spiked at concentrations of 9 0 and
           36 ragCa/1, the standard deviations were 0 3 and 0 6, respectively  Recoveries  at
           both these levels were 99%
                                         215 1-2

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                                     CALCIUM

                        Method 215.2  (Titrimetric,  EDTA)

                                     STORET NO. Calcium  (mg/1 CaCO3) 00910
                                                   Calcium, Total (mg/1 Ca) 00916

     Scope and Application
     1 1  This method is applicable to drinking and surface waters, domestic and industrial wastes
     1 2  The lower detection limit of this method is approximately 0 5 mg/1 as CaCO3, the upper
          limit can be extended to all concentrations by sample dilution It is recommended that a
          sample aliquot containing not more than 25 mg CaCO3 be used
     Summary of Method
     2 1  Calcium ion is sequestered upon the addition of disodium dihydrogen ethylenediamme
          tetraacetate (EDTA) The titration end point is detected by means of an indicator which
          combines with calcium only
     Interferences
     3 1  Strontium and barium  interfere  and alkalinity in excess of 30 mg/1 may cause an
          indistinct end point Magnesium interference is reduced or eliminated by raising the pH
          between 12-13 to precipitate magnesium hydroxide
     Apparatus
     4 1  Routine laboratory titnmetnc glassware
     Reagents
     5 1  Sodium hydroxide, NaOH, 1 N
     5 2  Indicators
          521 Many indicators are available, both laboratory prepared and commercial, and may
               be used Two are described here
          522 Murexide (ammonium purpurate) indicator This changes from pink to purple
               Dissolve 150 mg of the dye in 100 g absolute ethylene, glycol If a dry powder is
               preferred mix 200 mg murexide with 100 g solid NaCl and grind to 40 to 50 mesh
               Titrate immediately after adding indicator because it  is unstable under alkaline
               conditions
          523 Eriochrome Blue  Black R  (sodium-l-(2-hydroxy-l-naphthylazo)-2-naphthol-4-
               sulfonic acid) indicator This changes from red through purple to bluish purple to a
               pure blue without any trace of red or purple tint  The pH of some waters must be
               raised to 14 (rather than 12-13) by the use of 8 N NaOH in order to get a good
               color change Grind in a mortar 200 mg powdered dye and 100 g solid NaCl to 40
               to 50 mesh  Store in tightly stoppered bottle Use 0 2 g of this mixture for titration
Approved for NPDES
Issued  1974
Editorial revision  1978

                                        215 2-1

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 5 3   Standard  EDTA titrant, 0 02 N  Place 3 723 g analytical reagent grade disodium
      ethylenediamme tetraacetate dihydrate, Na2H2C10H12O8N22 H2O in a 1 liter volumetric
      flask and dilute to the mark with distilled water Check with standard calcium solution
      (5 3 1) by titration (5 3 5) Store in polyethylene Check periodically because of gradual
      deterioration
      531 Standard calcium solution, 0 02 N Place 1 000 g anhydrous calcium carbonate
           (pnmai y standard low in heavy metals, alkalies and magnesium) in a 500 ml
           flask Add, a little at a time 1 +1 HC1 (5 3 2) until all of the CaCO3 has dissolved
           Add 200 ml distilled water Boil for a few minutes to expel CO2 Cool Add a few
           drops of methyl red indicator (533) and adjust to intermediate orange color by
           adding 3N NH4OH  (5 3 4) or 1 +1 HC1 (5 3 2) as required Quantitatively
           transfer to a 1 liter volumetric flask and dilute to mark with distilled water
      532 Hydrochloric acid solution, 1 + 1
      5.3 3 Methyl red indicator  Dissolve 0 10 g methyl red in distilled water in a 100 ml
           volumetric flask and dilute to mark
      534 Ammonium hydroxide solution, 3 N
      535 Standardization titration procedure  Place 10 ml standard calcium solution
           (5 3 1) in a vessel containing about 50 ml distilled water Addl ml buffer solution
           (5 3 6) Add 1-2 drops indicator (5 3 7) or small scoop of dry indicator (5 3 7)
           Titrate slowly with  continuous stirring until the last reddish tinge disappears,
           adding last few drops at 3-5 second intervals  At end point the color is blue Total
           titration duration should be < 5 minutes from the time of buffer addition
                                                 62
                                N of EDTA = 	
                                               ml EDTA
      536 Buffer solution  Dissolve 16 9 g ammonium chloride in 143 ml cone ammonium
           hydroxide in a 250 ml volumetric flask Add 1 25 g of magnesium salt of EDTA
           (5 3 8) and dilute to the mark with distilled water Store in tightly stoppered plastic
           bottle
      537 Indicator  Commercially available Enochrome Black T is used in one of the three
           methods described All gradually detenorate
           5371    Mix 0 5 g dye with 4 5 g hydroxylamme hydrochlonde Dissolve in 100
                     ml of 95% ethanol or isopropanol
           5372    Place 0 5-1 0 g dye in 100 g of tnethanolamine or 2-methoxyethanol
           5373    Mix 0 5 g dye and 100 g NaCl for dry formulation
      538 EDTA Magnesium Salt Commercially available
Procedure
61   Pretreatment
      611  For drinking  waters, surface waters,  saline waters,  and dilutions thereof, no
           pretreatment steps are necessary Proceed to 6 2
      612 For most  wastewaters and highly polluted waters, the sample must be digested as
           given m the Atomic Absorption Methods section of this manual, paragraphs 413
           and 414  Following this digestion, proceed to 6 2
6 2   Sample Preparation
      621  The calcium content of the 50 ml aliquot to be titrated should be 5-10 mg,
           therefore dilution should be used for high calcium concentrations

                                    215 2-2

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           622 If the alkalinity is  > 300 mg/1 CaCO3 and cannot be reduced by dilution because
                of low calcium  concentration, the alkalinity must be decreased by acidifying,
                boiling one minute and cooling
     6 3   Titration
           631 Add 2 0 ml NaOH solution (5 1), or a volume sufficient to produce pH 12 to 13, to
                50 ml of sample
           632 Stir Add 0 1 to 0 2 g indicator (5 2 2, or 5 2 3) or 1-2 drops if indicator solution is
                used
           633 Immediately titrate with continuous stirring Check to see that no further color
                change occurs when using murexide (5 2 2) by adding 1 to 2 more drops of titrant
                after recording millihters of titrant at first judged end point
7    Calculations
     7 1   Total calcium

              ., _       A x N x 20,040
           m/1Ca=   ml of sample

                where
                A = ml titrant
                N = Normality of EDT A solution
     7 2   Calcium hardness

           mg/lCaC03=    Ax NX 50,000
                            ml of sample
           where A and N are the same as in 7 1
8    Precision and Accuracy
     81   A synthetic unknown sample containing 108 mg/1 Ca, 82 mg/1 Mg, 3 1 mg/1 K,  19 9
           mg/1 Na, 241 mg/1 chloride, 1 1 mg/1 nitrate N, 250 ug/l nitrite N, 259 mg/1 sulfate,
           and 42 5 mg/1 total alkalinity in distilled water was determined by this method with a
           relative standard deviation of 9 2% and a relative error of 19% in 44 laboratories

                                      Bibliography

1    Standard  Methods for the  Examination of Water and Wastewater,  14th Edition, p  189,
     Method 306C (1975)
2    Annual Book of ASTM  Standards, Part 31, "Water", Standard D511-76, Method B, p 253
     (1976)
                                         215 2-3

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                                    CHROMIUM

               Method 218.1 (Atomic  Absorption, direct aspiration)

                                                         STORET NO.  Total  01034
                                                                     Dissolved  01030
                                                                    Suspended  01031

Optimum Concentration Range:   0 5-10 mg/1 using a wavelength of 357 9 nm
Sensitivity:      0 25 mg/1
Detection Limit:      0 05 mg/1

Preparation of Standard Solution
      1     Stock Solution Dissolve 1 923 g of chromium tnoxide (CrO3, reagent grade) in deiomzed
           distilled water When solution is complete, acidify with redistilled HNO3 and dilute to 1
           liter with deiomzed distilled water  1ml  =  1 mg Cr (1000 mg/1)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1    The procedures for preparation of the sample as given in parts 411 thru 4 1 4 of the
          Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
      1    Chromium hollow cathode lamp
      2    Wavelength 357 9 nm
      3    Fuel Acetylene
      4    Oxidant Nitrous oxide
      5    Type of flame Fuel rich

Analysis Procedure
      1    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual


Approved for NPDES  and SDWA
Issued 1971
Editorial  revision 1974 and 1978

                                      218 1-1

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Notes
      1    The following wavelengths may also be used
           359 3 nm Relative Sensitivity 1 4
           425 4 nm Relative Sensitivity 2
           427 5 nm Relative Sensitivity 3
           428 9 nm Relative Sensitivity 4

      2    The fuel nch air-acetylene flame provides greater sensitivity but is subject to chemical
           and matrix interference from iron, nickel, and other metals If the analysis is performed
           m a lean flame the interference can be lessened but the sensitivity will also be reduced
      3    The suppression of both Cr (III) and Cr (VI) absorption by most interfering ions in fuel
           nch air-acetylene flames  is reportedly controlled by the addition of 1% ammonium
           bifluonde in 0 2% sodium sulfate [Talanta 20, 631 (1973)]  A 1% oxine solution is also
           reported to be useful
      4    For levels of chromium between 50 and 200 ug/1 where the air-acetylene flame can not
           be used or for  levels below  50 ug/1, either the furnace procedure or the extraction
           procedure is recommended  See Method 218 2 for the furnace procedure and Method
           218 3 for the chelation-extraction procedure
      5    For quality control  requirements  and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
      6    Data to be entered into STORET must be reported as ug/1
Precision and Accuracy
      1     An interlaboratory study on trace metal analyses by atomic absorption was conducted by
           the  Quality Assurance and Laboratory Evaluation  Branch of EMSL  Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples  The statistical results for
           chromium were as follows
                                                          Standard
Number        True Values          Mean Value           Deviation            Accuracy as
of Labs          ug/liter              ug/liter              ug/hter               %  Bias

  74             370                  353                  105                  -45
  76             407                  380                  128                  -65
  72              74                   72                   29                  -3 1
  70              93                   84                   35                 -102
  47               74                 10 2                  78                 37 7
  47              150                 160                  90                  68
                                         218 1-2

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                                     CHROMIUM

               Method 218.2 (Atomic Absorption,  furnace  technique)
                                                                STORET NO. 01034
                                                                      Dissolved 01030
                                                                     Suspended 01031
 Optimum Concentration Range:    5-100 ug/1
 Detection Limit:      1 ug/1
 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
      2    Calcium Nitrate Solution Dissolve 11 8  grams of calcium nitrate, Ca(NO3)2  4H2O
           (analytical reagent grade) in deiomzed distilled water and dilute to 100 ml 1 ml = 20 mg
           Ca
      3    Prepare dilutions of the stock chromium solution to be used as calibration standards at
           the time of analysis The calibration standards should be prepared to contain 0 5% (v/v)
           HNO3  To each 100 ml of standard and sample alike, add 1 ml of 30% H2O2 and 1 ml of
           the calcium nitrate solution

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method"  Sample solutions for analysis
           should contain 05% v/v HNO3

 Instrument Parameters (General)
      1     Drying Time and Temp 30sec-125C
      2     Ashing Time and Temp 30sec-1000C
      3     Atomizing Time and Temp 10sec-2700C
      4     Purge Gas Atmosphere Argon
      5     Wavelength 357 9 nm
      6     Other operating  parameters should be set as specified by the particular instrument
           manufacturer

 Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Approved  for NPDES and SDWA
 Issued 1978

                                        218 2-1

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Notes
     1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul mjecton, continuous flow purge gas and non-pyrolytic
           graphite
     2     Hydrogen peroxide is added to the acidified solution to convert  all chromium to the
           tnvalent state Calcium  is added to a level above 200 mg/1 where its suppressive effect
           becomes constant up to 1000 mg/1
     3     Background correction may be required if the sample contains high dissolved solids
     4     Nitrogen should not be used as a purge gas because of possible CN band interference
     5     Pipet tips have been reported to be a possible source of contamination (See part 5 2 9 of
           the Atomic Absorption Methods section of this manual)
     6     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     7     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     8.    For quality control requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
     9     Data to be entered into STORET must be reported as ug/1
                                                                I

Precision and Accuracy
     1     In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
           of 19, 48, and  77 ug  Cr/1,  the  standard  deviations  were  01,  0 2,  and 0 8,
           respectively Recoveries at these levels were 97%, 101%, and 102%, respectively
                                         218 2-2

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                                   CHROMIUM

             Method 218.3 (Atomic Absorption, chelation-extraction)
                                                              *
                                                             STORET  NO.   01034

1    Scope and Application
     1 1   This method covers the determination of total chromium in drinking, surface and saline
          waters The method may also be applicable to certain domestic and industrial wastes
          provided that no interfering substances are present (See 3 1)
     1 2   The method may be used to analyze samples containing from 1 0 to 25 ug of chromium
          per liter
     1 3   For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual
2    Summary of the Method
     2 1   This method is based on  the chelation  of hexavalent chromium with  ammonium
          pyrrohdme dithiocarbamate (APDC) following  oxidation of tnvalent chromium The
          chelate is extracted with methyl isobutyl ketone (MIBK) and aspirated into the flame of
          the atomic absorption spectrophotometer
     2 2   Hexavalent chromium may also be chelated with pyrrohdme dithiocarbamic acid in
          chloroform as described in section 9 2 of the atomic absorption text found in this manual
3    Interferences
     3 1   High concentrations of other reactive metals, as may be found in wastewaters, may
          interfere The method is free from interferences from elements normally occurring in
          fresh water
4    Instrumental Parameters (General)
     4 1   Chromium hollow cathode lamp
     4 2   Wavelength  357 9 nm
     4 3   Fuel Acetylene
     44   Oxidant Air
     4 5   Type of flame Fuel rich (adjust for organic solvent)
5    Reagents
     5 1   Ammonium  pyrrohdme dithiocarbamate (APDC) solution Dissolve 1 0 g APDC in
          demmerahzed water and dilute to 100 ml Prepare fresh daily
     5 2   Bromophenol blue indicator solution  Dissolve 0 1 g bromophenol  blue in  100 ml
          50-percent ethanol
     5 3   Potassium dichromate standard solution, 10ml  = 0 08 mg Cr Dissolve 0 2263 g dried
          analytical reagent grade K2Cr2O7 in demmerahzed water and make up to 1000 ml
     5 4   Tnvalent chromium stock solution,  10ml  = 0 002 mg Cr+3  Pipet 5 00 ml of the
          potassium  dichromate  standard  solution  (5 3)  into  an  Erlenmeyer flask   Add
          approximately  15 mg Na2SO3 and 0 5 ml concentrated HNO3  Gently evaporate to
                    /
Approved for  NPDES and SDWA
Issued  1978

                                       218 3-1

-------
          dryness, strong heating reoxidizes the chromium Add 05ml concentrated HNO3 and
          again evaporate to dryness to destroy any excess sulfite Take up m 1 ml concentrated
          HNO3 with warming and dilute to 200 Oml with demmerahzed water
     5 5  Trivalent chromium working solution, 10ml =0 005 mg Cr+3 Immediately before
          use, dilute 250 ml  of tnValent chromium stock solution (54) to 1000  ml with
          demmeralized water
     5 6  Potassium permanganate, 0 1 N Dissolve 0 32 g potassium permanganate in 100 ml
          demmeralized water
     5 7  Sodium azide, 01% Dissolve 100 mg sodium azide in deminerahzed water and dilute to
          100ml
     5 8  Methyl isobutyl ketone (MIBK)
     5 9  Sodium hydroxide solution, 1 M Dissolve 40 g NaOH in demmeralized water and dilute
          to 1 liter
     5.10 Sulfunc acid, 0 12 M  Slowly add 6 5 ml  concentrated H2SO4  (sp gr  184)  to
          demmeralized water and dilute to 1 liter
6.    Procedure
     6 1  Pipet a volume of sample contamig less than 2 5 ug chromium (100 ml  maximum) into a
          200 ml volumetnc flask, and adjust the volume to approximately 100 ml  The pH must
          be 2 0 or less Add concentrated HNO3 if necessary
     6 2  Acidify a liter of deminerahzed water with 1 5 ml concentrated HNO3 Prepare a blank
          and sufficient standards using tnvalent chromium and adjust volumes  to approximately
          100 ml with the acidified deminerahzed water
     6 3  Add 0 1 N KMnO4 dropwise to both standards and samples until a faint pink color
          persists
     6 4  Heat on a steam bath for 20 minutes If the color disappears, add additional KMnO4
          solution dropwise to maintain a slight excess
     6 5  While still on the steam bath, add sodium azide solution dropwise until the KMnO4 color
          just disappears Heat for about 2 mm between each addition and avoid adding any excess
          Continue heating for 5 mm after adding the last drop of sodium azide solution
     6 6  Transfer the flasks to a water bath and cool to room temperature
     6 7  Remove from the water bath and filter (through Whatman No  40 filter paper or
          equivalent) any sample which has a brownish precipitate  or coloration which may
          interfere with the pH adjustment
     6 8  Add 2 0 ml of 1 M NaOH and 2 drops bromophenol blue indicator solution Continue
          the addition of 1 M NaOH dropwise to all samples and standards in which the indicator
          change from yellow to blue has not occurred Add 0 12 M H2SO4 dropwise until the blue
          color just disappears, then add 2 0 ml m excess The pH at this point will be 2 4
     6 9  The pH adjustment to 2 4 may also be  made with a pH meter instead of using an
          indicator
     6.10  Add 50ml APDC solution and mix The pH should then be approximately 2 8
     611  Add 100ml MIBK and shake vigorously for 3 minutes
     6 12  Allow the  layers to separate and add demmeralized  water until the ketone layer is
          completely in the neck of the flask
                                        218 3-2

-------
613 Aspirate the ketone layer, record the instrument reading for each sample and standard
     against the blank Repeat, and average the duplicate results
Calculations
7 1  Determine the ug/1 Cr in each  sample from a plot of the instrument readings of
     standards A working curve must be  prepared with each set of samples  Report Cr
     concentrations as follows Less than 10 ug/1,  nearest ug/1,  10 ug/1 and above,  two
     significant figures
Precision and Accuracy
8 1  Precision and accuracy data are not available at this time
Reference
9 1  Atomic Absorption Newsletter 6, p 128 (1967)
                                    218 3-3

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                           CHROMIUM, HEXAVALENT

              Method 218.4 (Atomic Absorption,  chelation-extraction)

                                                                STORET NO. 01032

 1    Scope and Application
      1 1   This method covers the determination of dissolved hexavalent chromium in drinking,
           surface and saline waters The method may also be applicable to certain domestic and
           industrial wastes after filtration provided that no interfernng substances are present  (See
           41)
      1 2   The method may be used to analyze samples containing from 10 to 250 ug of chromium
           per liter
 2    Summary of the Method
      2 1   This method  is based on the chelation of hexavalent chromium with ammonium
           pyrrohdme  dithiocarbamate (APDC) and extraction  with  methyl isobutyl ketone
           (MIBK)  The  extract is aspirated  into  the  flame of  the  atomic absorption
           spectrophotometer
      2 2   Hexavalent  chromium  may also be chelated with pyrrohdme dithiocarbamic acid in
           chloroform as described in section 9 2 of the atomic absorption text found in this manual
           A pH of 2 3 must be maintained throughout the extraction
      2 3   The diphenylcarbazide colonmetnc procedure as found on p 192 of "Standard Methods
           for the Examination of Water and Wastewater",  14th edition, 1975, may also be used
 3     Sample Handling and Preservation
      3 1   Stability of hexavalent chromium is not completely understood at this time Therefore,
           the chelation and extraction should be earned out as soon as possible
      32   To retard  the chemical activity  of  hexavalent chromium, the sample should be
           transported and stored until time of anlysis at 4C
 4     Interferences
      4 1   High concentrations of other  reactive  metals,  as may be found in wastewaters, may
           interfere The method is free from interferences from elements normally occurring in
           fresh water
 5     Instrumental Parameters (General)
      5 1   Chromium hollow cathode lamp
      5 2   Wavelength  357 9 nm
      5 3   Fuel Acetylene
      5 4   Oxidant Air
      5 5   Type of Flame  Fuel rich (adjust for organic solvent)
 6     Reagents
      6 1   Ammonium pyrrohdme dithiocarbamate (APDC) solution  Dissolve 1 0 g APDC in
\          demmeralized water and dilute to 100 ml Prepare fresh daily

Approved for NPDES
Issued 1978

                                        2184-1

-------
      62   Bromophenol blue indicator solution  Dissolve 0 1  g bromophenol blue in 100 ml
           50-percent ethanol
      6 3   Chromium standard solution I, 1 0 ml  = 100 ug Cr Dissolve 0 2829 g pure, dried
           K2Cr2O7 in demmerahzed water and dilute to 1000 ml
      6 4   Chromium standard solution II, 1 0 ml = 10 0 ug Cr Dilute 100 ml chromium standard
           solution I to 1000 ml with demmerahzed water
      6 5   Chromium standard solution III,  1 0 ml  = 0 10 ug Cr  Dilute 10 0 ml chromium
           standard solution II to 1000 ml with deminerahzed water
      6 6   Methyl isobutyl ketone (MIBK)
      6 7   Sodium hydroxide solution,  1 M Dissolve 40 g NaOH in demmerahzed water and dilute
           to 1 liter
      6 8   Sulfunc acid, 0 12 M  Slowly add 6 5  ml concentrated H2SO4 (sp  gr  1 84) to
           deminerahzed water and dilute to 1 liter
7     Procedure
      7 1   Pipet a volume of sample containing less than 25 ug chromium (100 ml maximum)
           into a 200 ml volumetric flask, and adjust the volume to approximately 100 ml
      7 2   Prepare a blank and sufficient standards, and adjust the volume of each to approximately
           100ml
      7 3   Add 2 drops bromophenol blue indicator solution (The pH adjustment to 2 4 may also
           be made with a pH meter instead of using an indicator )
      7 4   Adjust the pH by addition of 1  M NaOH solution dropwise until a blue color persists
           Add 0 12 M H2SO4 dropwise until the blue color just  disappears in both the standards
           and sample Then add 2 0 ml of 0 12 M H2SO4 in excess The pH at this point should be
           24
      7 5   Add 5 0 ml APDC solution and mix The pH should then be approximately 2 8
      7.6   Add 10 0 ml MIBK and shake vigorously for 3 minutes
      7 7   Allow  the  layers  to separate and add demmerahzed water until the  ketone layer is
           completely in the neck of the flask
      7 8   Aspirate the ketone layer and record the scale reading for each sample and standard
           against the blank Repeat, and average the duplicate results
8.     Calculations
      8 1   Determine the ug/1 Cr+s m each sample from a plot of scale readings of standards A
           working curve must be prepared with each set of samples Report Cr+6 concentrations as
           follows Less than 10 ug/1, nearest ug/1,10 ug/1 and above, two significant figures
9     Precision and Accuracy
      91   In a single laboratory (EMSL), using the (PDCA) extraction procedure and Cincinnati
           Ohio tap water spiked at a concentration of 50 ug Cr+/l the standard deviation was
           2.6 with a mean recovery of 96%
                                        2184-2

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                               United States
                               Environmental Protection
                               Agency
                               Environmental Monitoring and
                               Support Laboratory
                               Cincinnati OH 45268
                               Research and Development
vxEPA
Test  Method
                              Chromium,  Dissolved
                              Hexavalent  (Atomic
                              Absorption,  Furnace
                              Technique)Method  218.5
                              1   Scope and Application

                              1 1  This method covers the
                              determination of dissolved hexavalent
                              chromium (Cr6+) m drinking and
                              surface waters The method may also
                              be applicable to certain domestic and
                              industrial wastes after filtration
                              provided that potential interfering
                              substances are taken into account
                              (See 41 )

                              1 2  The method may be used to
                              analyze samples containing from 5 to
                              100 yug of Cr6+ per liter  The range of
                              the method may be extended upward
                              by dilution

                              2   Summary of Method

                              2 1  The method is based on the
                              separation of Cr6+ from the sample by
                              coprecipitation of lead chromate with
                              lead sulfate in a solution of acetic
                              acid  After separation, the supernate
                              is drawn off and the Cr6 precipitate
                              resolubihzed in nitric acid as tnvalent
                              chromium (Cr3+) and quantified by
                              furnace atomic absorption

                              2 2  Hexavalent chromium may also
                              be analyzed by the chelation/
                              extraction technique (see Method
                              218 4 or the procedure described in
                              9 2 of the Atomic Absorption methods
                              found in this manual)
                              3   Sample Handling and
                              Preservation

                              3 1 For sample handling  cleaning
                              glassware and the filtration procedure
                              see part 4 1 of the Atomic Absorption
                              Method section of this manual

                              3 2 The sample must not be
                              preserved by acidification, but instead
                              transported and stored until time of
                              analysis at.4C

                              3 3 Stability of Cr6+ in environmental
                              samples is n ot completely  understood
                              at this time  The chemical nature of
                              the sample matrix can have a definite
                              affect on the chemistry of chromium
                              Therefore the analysis should be
                              carried out as soon as possible but no
                              longer than 24 hours after collection

                              4   Interferences

                              4 1 The possible interference from
                              other elements which form stable
                              chromates is not known at this time

                              4 2 Samples with either sulfate or
                              chloride concentrations above 1000
                              mg/liter should be diluted before
                              analysis

                              4 3 The potential reduction of Cr6+
                              from highly reductive substances
                              increases as pH is lowered  When
                              sulfites and sulfides are present the
                              2185-1
                                                   Dec 1982

-------
 sample aliquot taken for analysis
 should be neutralized and aerated
 before beginning

 5.   instrument Parameters
 (General)

 5.1  Drying Time and Temp 30 sec-
 125C

 5.2  Ashing Time and Temp  30 sec-
 1000C

 5.3  Atomizing Time and Temp  10
 sec-2700C

 5.4  Purge Gas Atmosphere  Argon

 5.5  Wavelength  357 9nm

 5 6  Other operating parameters
 should be as specified by the
 particular instrument manufacturer
 6.  Special Apparatus

 6 1   Glassware

 6.1  J   Filtering flask, heavy wall, 1
 liter capacity

 5.1 2   Centrifuge tubes, heavy duty,
 conical, graduated, glass stoppered,
 10 mL capacity

 6.1.3   Pasteur pipets, borosilicate
 glass, 5 34 inches

 6 2  Centrifuge any centrifuge
 capable of reaching 2000 rpm and
 accepting the centrifuge tubes
 described in 6 1 2 may be used

 63  pH Meter a wide variety of
 instruments are commercially
 available and suitable for this work

 6 4  Test Tube Mixer any mixer
 capable of thorough vortex is
 acceptable
7.   Reagents

7.1  Lead Nitrate Solution  Dissolve
33 1 grams of lead nitrate, Pb(NO3)2
(analytical reagent grade), in deionized
distilled water and dilute to 100 mL

7.2  Ammonium Sulfate Solution
Dissolve 2 7 grams of ammonium
sulfate, (NH<)2SO< (analytical reagent
grade), in deionized distilled water and
dilute to 100mL

7 3  Calcium Nitrate Solution
Dissolve 118 grams of calcium
nitrate, Ca(NO3)z  4HaO (analytical
reagent grade), in. deionized distilled
water and dilute to 100 mL T  mL =
20 mg Ca.
 7 4  Nitric Acid, cone  Distilled
 reagent grade or equivalent to
 spectrograde quality

 7 5  Acetic Acid, Glacial ACS
 reagent grade

 751 Acetic Acid, 10% (v/v)  Dilute
 10 mL glacial acetic acid to 100 mL
 with deionized distilled water

 7 6  Ammonium Hydroxide, 10%
 (v/v)  Dilute 10 mL cone ammonium
 hydroxide, NH4OH (analytical reagent
 grade), to 100 mL with deionized
 distilled water

 7 7  Hydrogen Peroxide, 30%  ACS
 reagent grade

 7 8  Potassium Dichromate Standard
 Solution  Dissolve 2 8285 grams of
 dried  potassium dichromate,  KaCraO?
 (analytical reagent grade), in deionized
 distilled water and dilute to 1  liter 1
 mL =  1 mg Cr (1000 mg/L)

 7 9  Tnvalent Chromium Working
 Stock Solution  To 50 mL of the
 potassium dichromate standard
 solution (7 8) add 1  mL of 30% H202
 (7 7) and 1 mL cone HN03 (7 4) and
 dilute to  100 mL with deionized
 distilled water 1 mL = 0 5 mg Cr3+
 Prepare fresh monthly or as needed
8   Calibration

81  At the time of analysis prepare a
blank and a series of at least four
calibration standards from the Cr3+
working stock (7 9) that will
adequately bracket the sample  The
normal working range covers a
concentration range of 5 to  100 ug
Cr/L  Add to the blank and each
standard 1 mL 30% H2O2 (7 7),  5 mL
CONC HNOa (7 4), and 1  mL calcium
nitrate solution  (7 3) for each 100 mL
of prepared solution before diluting to
final volume These calibration
standard should be prepared fresh
weekly or as needed

8 2  The listed instrumental
conditions (5 ) and the stated
calibration concentration range are for
a Perkm-Elmer HGA-2100 based on
the use of a 20/uL injection,  contmous
flow purge gas and non-pyrolytic
graphite  The use of simultaneous
background correction is required for
both calibration and sample analysis

9   Procedure

9 1  Transfer a 50 mL portion of the
filtered sample to a 10OmL Griffin
beaker and adjust to pH 3 50 3 by
adding 10% acetic acid dropwise
Record the volume of acid added and
adjust the final result to account for
the dilution
Note  Care must be exercised not to
take the pH below 3 If the pH is
inadvertently lowered to < 3, 10%
NH4OH (7 6) should be used to raise
the pH to above 3

9 2   Pipet a 10  mL aliquot  of the
adjusted sample into a centrifuge tube
(6 1 2) Add 100/A. of the  lead nitrate
solution (7 1), stopper the tube, mix the
sample and allow to stand for 3mm

9 3   After the formation of lead
chromate, retain the Cr3+ complex in
solution by addition of 0 5 mL glacial
acetic acid (7 5)  Stopper and mix

94   To provide adequate lead sulfate
for coprecipitation add 100 mL
ammonium sulfate solution (7 2),
stopper and mix

9 5   Place the stoppered centrifuge
tube in the centrifuge, making sure
that the tube  is properly
counterbalanced Start the centrifuge
and slowly increase the  speed to
2000 rpm in small increments over a
period of 5 mm Centrifuge the sam-
ple at 2000 rpm for 10 mm
Note 2 The speed of the centrifuge
must  be increased slowly to insure
complete coprecipitation

9 6   After centrifugmg remove the
tube and draw off the supernate using
the apparatus detailed in Figure 1  As
the pasteur pipet is lowered into the
tube the supernate is sucked into the
filtering flask  With care the supernate
can be withdrawn to within
approximately 0 1 mL above the
precipitate

97   To the remaining precipitate  add
0 5 mL cone HN03 (7 4), 100/L/L 30%
H202 (7 7) and 100//L calcium nitrate
solution (7 3)  Stopper the tube and
mix using  a vortex mixer to disrupt
the precipitate and solubilize the lead
chromate  Dilute to 10mL, mix and
analyze in the same manner as the
calibration standard (8 2)

9 8   For the general furnace
procedure and calculation, see
 Furnace Procedure part 9 3 of the
Atomic Absorption Methods section of
this manual

10   Verification

101  For every sample  matrix
analyzed verification is necessary to
determine that neither a reducing
condition nor  a chemical interference
affecting precipitation is  present  This
                                     Dec  1982
                                                                  2185-2

-------
 must be accomplished by analyzing a
 second 10mL aliquot of the pH
 adjusted filtrate (9 1) spiked with Cr6*
 (7 8)  The amount of spike added
 should double the concentration found
 in the original aliquot Under no
 circumstance should the increase be
 of less than 3Qug Cr6+/L  To verify the
 absence of an interference the spike
 recovery should be between 85% and
 115%

 102   If the addition of the spike
 extends the concentration beyond the
 range of the calibration curve, the
 analysis solution should be diluted
 with blank solution and the calculated
 results adjusted accordingly

 103  If the verification indicates a
 suppressive interference, the sample
 should be diluted and reanalyzed


 11   Analytical Notes

 111  Nitrogen should not be used as
 a purge gas  because of possible CN
 band  interference

 112  The use of pyrolytic graphite
 should be  avoided when possible
 Generally, pyrolytic graphite resulted
 in a more  limited analytical working
 range and in some situations an
 enhancement effect

 113  Pipet tips have been reported
 to be  a possible source of
 contamination (See part 5 2 9 of the
 Atomic Absorption Methods section of
 this manual)

 114  The method of standard
 addition should not be required in as
 much as the Cr6+ has been separated
 from the original sample solution and
 redissolved in a uniform  matrix having
 an absorption response coincident to
 the calibration curve

 115  Data  to be entered into
 STORET (No 01032) must be reported
 as jug/L
123   Using Cincinnati, Ohio tap
water spiked at concentrations of
5,10, and 50 //g Cr6+/L the standard
deviations were 07, 0 6, and
0 6  respectively Spike recovery at
all three levels was 102%

124   A 1000 fjtS Cr3VL standard
solution analyzed by this method
yielded a result of 8 yug Cr6+/L with  a
relative standard deviation of 19%

125   The data from 5 /jg Cr6+/L tap
water spike was used to calculate
method detection limit (MDL) with
99% confidence as described in
 Trace Analyses for Wastewater," J
Glaser, D  Foerst, G McKee, S
Quave, W  Budde, Environmental
Science and Technology Vol 15,
Number 12, page 1426, December
1981  The calculated MDL for
Cincinnati drinking water is 2 3 /ug/L
12   Precision and Accuracy

121  In a single laboratory (EMSL)
using a mixed industrial-domestic
waste effluent containing 22 /ug
Cr8VL and spiked with a
concentration of 50 A/g Cr8Vl_ the
standard deviations were 10 and 
2 7, respectively with a spike recovery
of 94%

122  Recoveries of a 40 /ug Cr6VL
spike in  diluted tannery and plating
waste effluents  were 96% and 93%,
respectively
                                      2185 3
                                                                Dec  1982

-------
                                       COBALT
               Method 219.1 (Atomic  Absorption, direct aspiration)

                                                         STORET NO.  Total 01037
                                                                      Dissolved 01035
                                                                    Suspended 01036

Optimum Concentration Range:        0 5-5 mg/1 using a wavelength of 240 7 nm
Sensitivity.      0 2 mg/1
Detection Limit:      0 05 mg/1

Preparation of Standard Solution
      1     Stock Solution Dissolve 4 307 g of cobaltous chloride, CoCl26H2O (analytical reagent
           grade), in deiomzed distilled water Add 10 ml of concentrated nitric acid and dilute to 1
           liter with deiomzed distilled water 1 ml =  1 mg Co (1000 mg/1)
      2     Prepare dilutions of the stock cobalt solution to be used as calibration standards at the
           time of analysis  The calibration standards should be prepared using the same type of
           acid and at the same concentration as will result in the sample to be analyzed either
           directly or after processing

Sample Preservation
      1     For  sample handling and preservation, see  part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The  procedures for preparation of the sample as given in parts 411 thru 4 1 4 of the
           Atomic Absorption Methods section of this  manual have been found to be satisfactory

Instrumental Parameters (General)
      1     Cobalt hollow cathode lamp
      2     Wavelength 240 7 nm
      3     Fuel Acetylene
      4     Oxidant Air
      5     Type of Flame  Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual
Approved for NPDES
Issued 1974
Editorial revision 1978
                                        219 1-1

-------
Notes
     1     For levels of cobalt below 100 ug/1, either the Special Extraction Procedure, given in
           part 9 2 of the Atomic Absorption Methods section or the furnace technique, Method
           219 2 is recommended
     2     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     In a single laboratory (EMSL), using  a mixed industrial-domestic waste effluent at
           concentrations of 0 20,1 0 and 5 Omg Co/1, the standard deviations were 0 013,  0 01
           and 005,  respectively  Recoveries at these  levels  were 98%,  98%,  and  97%,
           respectively
                                        219 1-2

-------
                                       COBALT

               Method 219.2  (Atomic Absorption, furnace technique)
                                                         STORET NO. Total  01037
                                                                      Dissolved  01035
                                                                     Suspended  01036
 Optimum Concentration Range:   5-100 ug/1
 Detection Limit:      1 ug/1
 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3    The calibration standard should be diluted to contain 0 5 % (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method"  Sample solutions for analysis
           should contain 05% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp 30sec-125'C
      2    Ashing Time and Temp 30sec-900C
      3    Atomizing Time and Temp  10sec-2700C
      4    Purge Gas Atmosphere Argon
      5    Wavelength  240 7 nm
      6    Other operating  parameters should be set as specified  by the particular instrument
           manufacturer

 Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

 Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic

Approved for NPDES
Issued 1978

                                        2192-1

-------
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
      2    The use of background correction is recommended
      3.    Nitrogen may also be used as the purge gas but with reported lower sensitivity
      4    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5    If method of standard addition is required, follow the procedure given earlier m part 8 5
           of the Atomic Absorption Methods section of this manual
      6    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         219 2-2

-------
                                       CQPPER
                Method 220.1 (Atomic  Absorption, direct aspiration)
                                                          STORET NO. Total  01042
                                                                       Dissolved  01040
                                                                     Suspended  01041
 Optimum Concentration Range:   0 2-5 mg/1 using a wavelength of 324 7 nm
 Sensitivity:     0 1 mg/1"
 Detection Limit:       002 mg/1

 Preparation of Standard Solution
      1    Stock Solution Carefully weigh 1 00 g of electrolyte copper (analytical reagent grade)
           Dissolve in 5 ml redistilled HNO3 and make up to 1 liter with deiomzed distilled water
           Final concentration is 1 mg Cu per ml (1000 mg/1)
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result m the sample to be analyzed either directly or after
           processing

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    The procedures for preparation of the sample  as given in parts 411 thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

 Instrumental Parameters (General)
      1    Copper hollow cathode lamp
      2    Wavelength 324 7 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5     Type of flame Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
Approved for NPDES
Issued 1971
Editorial revision 1974 and 1978

                                        220 1-1

-------
Notes
     1     For levels of copper below 50 ug/1, either the Special Extraction Procedure, given in part
           9 2 of the Atomic Absorption Methods section or the furnace technique, Method 220 2,
           is recommended
     2.    Numerous absorption lines are available for the determination of copper  By selecting a
           suitable absorption wavelength, copper samples may be analyzed over a very wide range
           of concentration The folio wing lines may be used
           327.4 nm Relative Sensitivity 2
           216.5 nm Relative Sensitivity 7
           222.5 nm Relative Sensitivity 20
     3     Data to be entered into STORET must be reported as ug/1
     4     The 2,9-dimethyl-l, 10-phenanthrohne colonmetnc method may also be used (Standard
           Methods, 14th Edition, p 196)

Precision and Accuracy
     1.    An mterlaboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance and Laboratory Evaluation Branch of EMSL  Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples The statistical results for
           copper were as follows
                                                         Standard
 Number        True Values          Mean Value           Deviation           Accuracy as
 of Labs           ug/liter              ug/liter              ug/hter              % Bias
  91              302                  305                   56                    09
  92              332                  324                   56                   -24
  86               60                   64                   23                    70
  84               75                   76                   22                    13
  66               75                  97                  61                 297
  66               120                 139                  97                 155
                                         220 1-2

-------
                                       COPPER

               Method 220.2 (Atomic  Absorption,  furnace  technique)
                                                                STORET NO. 01042
                                                                      Dissolved 01040
                                                                     Suspended 01041
 Optimum Concentration Range:    5-100 ug/1
 Detection Limit:       lug/1
 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3    The calibration standard should be diluted to contain 05% (v/v) HNO3

 Sample Preservation
      1    For sample handling and  preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method"  Sample solutions for analysis
           should contain 05% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp 30sec-125C
      2    Ashing Time and Temp 30sec-'900C
      3    Atomizing Time and Temp 10sec-2700C
      4    Purge Gas Atmosphere Argon
      5    Wavelength 324 7 nm
      6    Other operating  parameters should be set as specified by the particular  instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
      1    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
          2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic

Approved for  NPDES
Issued 1978

                                        220 2-1

-------
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time penods than the
           above recommended settings
     2     Background correction may be required if the sample contains high dissolved solids
     3     Nitrogen may also be used as the purge gas
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5.    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                          220 2-2

-------
                                         GOLD

                Method 231.1 (Atomic Absorption,  direct aspiration)

                                                          STORET NO.  Total  71910

 Optimum Concentration Range:   0 5-20 mg/1 using a wavelength of 242 8 nm
 Sensitivity:     0 25 mg/1
 Detection Limit:      0 1 mg/1

 Preparation of Standard Solution
      1    Stock Solution Dissolve 0 1000 g of gold metal in a minimum volume of aqua regiaf
           Take to near dryness, cool, add 5 ml HC1, and dilute to 100 ml with deionized water
           Store in an amber glass bottle  (1 ml  =  1 mg Au)
      2    A standard AAS solution of chloroaunc acid, HAuCl4, 1000 mg/1 in aqueous matrix is
           available from Alfa Products, Beverly, Massachusetts 01915
           Cat  #88068
      3    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared to contain 05% (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Transfer a representative  aliquot of the well mixed sample to a Griffin beaker and add 3
           ml of cone distilled HNO3 Place the beaker on a steam bath and evaporate to near
           dryness Cool the beaker and cautiously  add a 5 ml portion of aqua regia  (See below for
           preparation of aqua regia  f) Cover the beaker with a watch glass and return to the steam
           bath Continue heating the covered beaker for 30 minutes Remove cover and evaporate
           to near dryness Cool and  add 1 1 distilled HNO3 (1 ml per 100 ml dilution) Wash down
           the beaker walls and watch glass with distilled water and filter the sample to remove
           silicates and other insoluble material that could clog the atomizer Adjust the volume to
           some predetermined value based on the expected metal concentration The sample is now
           ready for analysis
fAqua regia-prepare immediately before use by carefully adding three volumes of
cone HCL to one volume of cone HNO3

Approved for NPDES
Issued  1976
Technical revision 1978
                                         231 1-1

-------
Instrumental Parameters (General)
      1     Gold hollow cathode lamp
      2     Wavelength 242 8 nm
      3     Fuel Acetylene
      4     Oxidant Air
      5.    Type of flame Oxidizing

Analysis Procedure
      1.    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
                             %
Notes
      1     For concentrations  of gold below 100 ug/1, the furnace procedure, Method 231 2, is
           recommended

Precision and Accuracy
      1.    Precision and accuracy data are not available at this time
                                         231 1-2

-------
                                         GOLD

               Method 231.2 (Atomic  Absorption, furnace technique)
                                                                STORET  NO. 71910
 Optimum Concentration Range:   5-100 ug/1
 Detection Limit:                1 ug/1

 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3    The calibration standard should be diluted to contain 0 5% (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain 0 5% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp 30sec-125C
      2    Ashing Time and Temp 30sec-600C
      3    Atomizing Time and Temp 10sec-2700C
      4    Purge Gas Atmosphere Argon
      5    Wavelength 242 8 nm
      6    Other operating parameters should  be  set  as specified by the particular instrument
           manufacturer

 Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of his manual

 Notes
      1    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
          2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
          graphite
Approved for NPDES
Issued 1978

                                        231 2-1

-------
     2     The use of background correction is recommended
     3     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     4     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     5     Data to entered into STORET must be reported as ug/1
                                                                                   ii i<
Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         231 2-2

-------
                                      IRIDIUM
     "                                            i  
               Method 235.1 (Atomic Absorption, direct aspiration)

                                                                STORET NO.  Total*

Optimum Concentration Range:   20-500 mg/1 using a wavelength of 264 0 nm
Sensitivity:      8 mg/1
Detection Limit*      3 mg/1

Preparation of Standard Solution
     1     Stock Solution Dissolve 1 147 g of ammonium chloroindate (NH4)2 IrCl6, in a minimum
           volume of 1 % (v/v) HC1 and dilute to 100 ml with 1 % HC1 (1 ml = 5 mg Ir)
     2     A standard AAS solution of chloroindic acid, H2IrCl6, 1000 mg/1 in aqueous matrix is
           available from Alfa Products, Beverly, Massachusetts 01915
       *   Cat  #88072
     3     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared to contain 05% (v/v) HNO3

Sample Preservation
     1     For  sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     Transfer a representative aliquot of the well mixed sample to a Gnffiu beaker and add 3
           ml of cone  distilled HNO3  Place the beaker on a steam bath and evaporate to near
           dryness Cool the beaker and cautiously add a 5 ml portion of aqua regia (See below for
           preparation of aqua regia f) Cover the beaker with a watch glass and return to the steam
           bath Continue heating the covered beaker for 30 minutes Remove cover and evaporate
           to near dryness  Cool and add 1 1 distilled HNO3 (1 ml per 100 ml dilution) Wash down
           the beaker walls and watch glass with distilled water and filter the sample to remove
           silicates and other insoluble material that could clog the atomizer  Adjust the volume to
           some predetermined value based on the expected metal concentration  The sample is now
           ready for analysis
fAqua regia-prepare immediately before use by carefully adding three volumes
cone HC1 to  one volume of cone  HNO3

*Not Assigned

Approved for NPDES
Issued  1976
Technical revision 1978

                                         235 1-1

-------
Instrumental Parameters (General)
      1.    Indium hollow cathode lamp
      2.    Wavelength 264 Onm
      3     Fuel Acetylene
      4     Oxidant Air
                                                            	             '      MI
      5.    Type of flame Reducing

Analysis Procedure
      1.    For analysis and calculation, see "Direct Aspiration", part 9 1 of the Atomic Absorption
           Methods section of this manual

Notes
      1.     For concentrations of indium below 3 mg/1, the furnace procedure, Method 235 2, is
           recommended

Precision and Accuracy
      1.     Precision and accuracy data are not available at this time
                                        235 1-2

-------
                                      IRIDIUM

              Method 235.2 (Atomic  Absorption, furnace technique)

                                                                  STORET NO. Total*

Optimum Concentration Range:   0 1-1 5mg/l
Detection Limit:      0 03 mg/1

Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calculation standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as descnbed under "direct aspiration  method" Sample solutions for analysis
           should contain 0 5% (v/v) HNO3

Instrument Parameters (General)
      1     Drying Time and Temp  30sec-125C
      2     Ashing Time and Temp  30sec-600C
      3     Atomizing Time and Temp  10sec-2800C
      4     Purge Gas Atmosphere  Argon
      5     Wavelength 264 Onm
      6     Other operating parameters should be set as  specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation,  see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
*Not  Assigned

Approved for NPDES
Issued 1978
                                        235 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite
     2     The use of background correction is recommended
     3     Nitrogen may also be used as the purge gas
     4     The 208 9 nm line is a factor of 3X more sensitive than the 264 0 nm line, but requires a
           very narrow slit to be discriminated from nearby non-absorbing lines
     5     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required  (see  part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     6     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         235 2-2

-------
                                        IRON
               Method 236.1 (Atomic Absorption, direct aspiration)

                                                         STORET NO.  Total  01045
                                                                     Dissolved  01046
                                                                    Suspended  01044

Optimum Concentration Range:   0 3-5 mg/1 using a wavelength of 248 3 nm
Sensitivity:     0 12 mg/1
Detection Limit       0 03 mg/1

Preparation of Standard Solution
      1     Stock Solution Carefully weigh 1 000 g of pure iron wire (analytical reagent grade) and
           dissolve in 5 ml redistilled HNO3, warming if necessary When solution is complete make
           up to 1 liter with deiomzed distilled water 1 ml = 1 mg Fe (1000 mg/1)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1  of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The procedures for preparation of the sample as given in parts 411 thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
      1     Iron hollow cathode lamp
      2     Wavelength 248 3 nm
      3     Fuel Acetylene
      4     Oxidant Air
      5     Type of flame Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct  Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
Approved for NPDES
Issued 1971
Editorial revision 1974 and 1978

                                        236 1-1

-------
Notes
     1     The following lines may also be used
           248 8 nm Relative Sensitivity 2
           271 9 nm Relative Sensitivity 4
           302 1 nm Relative Sensitivity 5
           252 7 nm Relative Sensitivity 6
           372 0 nm Relative Sensitivity 10
     2     Data to be reported into STORET must be reported as ug/1
     3.    The  1,10-phenanthrokne colonmetnc method may also be used (Standard Methods,
           14th Edition, p 208)
     4.    For concentrations of iron below 0 05 mg/1, either the Special Extraction Procedure
           given m part 9 2 of the Atomic Absorption Methods section or the furnace procedure,
           Method 236 2, is recommended

Precision and Accuracy
     1     An mterlaboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance and Laboratory  Evaluation Branch of EMSL Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chrommm, copper, iron,,
           manganese, lead and zinc were added to natural water samples  The statistical results for
           iron were as follows
                                                         Standard
Number        True Values         Mean Value           Deviation           Accuracy as
Of Labs          ug/liter              ug/liter              ug/hter              % Bias

  82             840                  855                  173                    1 8
  85             700                  680                  178                   -28
  78             350                  348                  131                   -Or5
  79             438                  435                  183                   -07
  57              24                   58                   69                  141
  54              10                   48                   69                  382
                                         236 1-2

-------
                                        IRON
              Method 236.2 (Atomic  Absorption,  furnace technique)

                                                        STORET  NO. Total 01045
                                                                     Dissolved 01046
                                                                    Suspended 01044

Optimum Concentration Range:   5-100 ug/1
Detection Limit:       1 ug/1

Preparation of Standard Solution
     1    Stock Solution Prepare as described under "direct aspiration method"
     2,   Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 0 5 % (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as descnbed under "direct aspiration method" Sample  solutions for analysis
          should contain 0 5% (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-1000C
     3    Atomizing Time and Temp  10sec-2700C
     4    Purge Gas Atmosphere Argon
     5    Wavelength 248 3 nm
     6    Other operating parameters should be set as  specified by the particular  instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual

Notes
     1    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
          2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
Approved for NPDES
Issued  1978

                                        236 2-1

-------
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
     2     The use of background correction is recommended
     3     Nitrogen may also be used as the purge gas
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         236 2-2

-------
                                        LEAD
               Method 239.1 (Atomic Absorption, direct  aspiration)

                                                         STORET  NO. Total 01051
                                                                      Dissolved 01049
                                                                     Suspended 01050

Optimum Concentration Range:   1-20 mg/1 using a wavelength of 283 3 nm
Sensitivity:      0 5 mg/1
Detection Limit:      0 1 mg/1

Preparation of Standard Solution
      1     Stock Solution  Carefully weigh 1 599 g of lead nitrate,  Pb(NO3)2 (analytical reagent
           grade), and dissolve in deiomzed distilled water When solution is complete acidify with
           10 ml redistilled HNO3 and dilute to 1 liter with deiomzed distilled water 1 ml =  1 mg
           Pb (1000 mg/1)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The  procedures for preparation of the sample as given in parts 411  thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
      1     Lead hollow cathode lamp
      2     Wavelength 283 3 nm
      3     Fuel  Acetylene
      4     Oxidant  Air
      5     Type of flame Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
Approved for NPDES  and SDWA
Issued 1971
Editorial revision 1974 and  1978

                                         239 1-1

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Notes
     1.    The analysis of this metal is exceptionally sensitive to turbulence and absorption bands in
           the flame Therefore, some care should be taken to position the light beam m the most
           stable, center portion of the flame To do this, first adjust the burner to maximize the
           absorbance reading with a lead standard Then, aspirate a water blank and make minute
           adjustments in the burner alignment to minimize the signal
     2     For levels of lead below 200 ug/1, either the Special Extraction Procedure given in part
           9 2 of the Atomic Absorption Methods section or the furnace technique, Method 239 2,
           is recommended
     3.    The following lines may also be used
           217 0 nm Relative Sensitivity 0 4
           261 4 nm Relative Sensitivity 10
     4     For quality control  requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
     5     Data to be entered into STORET must be reported as ug/1
Precision and Accuracy
      1     An Intel-laboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance and Laboratory Evaluation Branch of EMSL Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples The statistical results for
           lead were as follows
                                                         Standard
Number        True Values         Mean Value           Deviation           Accuracy as
of Labs          ug/hter              ug/liter              ug/liter              % Bias

   74              367                 377                  128                   29
   74              334                 340                  111                   18
   64              101                 101                  46                  -O2
   64               84                  85                  40                   11
   61               37                  41                  25                   96
   60               25                  31                  22                  257
                                         239 1-2

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                                       LEAD
             Method  239.2 (Atomic Absorption, furnace technique)

                                                        STORET  NO. Total 01051
                                                                    Dissolved 01049
                                                                   Suspended 01050

Optimum Concentration Range:   5-100 ug/1
Detection Limit:      1 ug/1

Preparation of Standard Solution
     1    Stock solution Prepare as descnbed under "direct aspiration method"
     2    Lanthanum Nitrate Solution Dissolve 58 64 g of ACS reagent grade La2O3 in 100 ml
          cone HNO3 and dilute to 1000 ml with deiomzed distilled water 1 ml = 50 mg La
     3    Working Lead Solution  Prepare  dilutions of the  stock lead solution to be used  as
          calibration standards at the time of analysis  Each calibration standard should contain
          05% (v/v) HNO3  To each 100 ml of diluted standard add 10 ml of the lanthanum
          nitrate solution

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section qf this manual

Sample Preparation
     1    Prepare as descnbed under "direct aspiration method" Sample solutions for analysis
          should contain 05% (v/v) HNO3
     2    To each 100 ml of prepared sample solution add 10 ml of the lanthanum nitrate solution

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-500C
     3    Atomizing Time and Temp  10sec-2700C
     4    Purge Gas Atmosphere Argon
     5    Wavelength 283 3 nm
     6    Other  operating parameters should be  set as specified by the  particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure in the calculation see "Furnace Procedure", part 9 3  of the
          Atomic Absorption Methods section of this manual
Approved for NPDES and SDWA
Issued 1978

                                        239 2-1

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Notes
     1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 u\ injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings   '
     2     The use of background correction is recommended
     3     Greater sensitivity can be achieved using  the  2170 nm line, but  the  optimum
           concentration range is reduced The use of a lead electrodeless discharge lamp at this
           lower wavelength has  been  found  to be advantageous  Also a lower atomization
           temperature (2400C) may be preferred
     4     To suppress sulfate interference (up  to 1500 ppm) lanthanum is added as the nitrate to
           both samples and calibration standards (Atomic Absorption Newsletter Vol 15, No 3,
           p 71, May-June 1976)
     5     Since glassware contamination is a severe problem in lead analysis, all glassware should
           be cleaned immediately prior to use, and once cleaned, should  not be open to the
           atmosphere except when necessary
     6     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     7     For quality control requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
     8     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     9     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
           of 25, 50, and  100 ug Pb/1, the  standard deviations were  \ 3, 1 6,  and 37,
           respectively Recoveries at these levels were 88%, 92%, and 95% respectively
                                         239 2-2

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                                   MAGNESIUM
               Method 242.1 (Atomic  Absorption, direct  aspiration)

                                                         STORET NO. Total 00927
                                                                      Dissolved 00925
                                                                     Suspended 00926

Optimum Concentration Range:   0 02-0 5 mg/1 using a wavelength of 285 2 nm
Sensitivity:      0 007 mg/1
Detection Limit:      0 001 mg/1

Preparation of Standard Solution
     1     Stock Solution Dissolve 0 829 g of magnesium oxide, MgO (analytical reagent grade), in
           10 ml of redistilled HNO3 and dilute to 1 liter with deiomzed distilled water 1 ml = 0 50
           mgMg (500 mg/1)
     2     Lanthanum chloride solution Dissolve 29 g of La2O3, slowly and in small portions in 250
           ml cone HC1, (Caution Reaction is violent), and dilute to 500 ml with deiomzed distilled
           water
     3     Prepare dilutions of the stock magnesium solution to be used as calibration standards at
           the time of analysis To each 10 ml volume of calibration standard and sample alike add
           1 0 ml of the lanthanum chloride solution, i e , 20 ml of standard or sample +2 ml LaCl3
           = 22 ml

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     For the analysis of total magnesium in domestic and industrial effluents, the procedures
           for the determination of total metals as given in parts 413 and 4 1 4 of the Atomic
           Absorption Methods section of this manual have been found to be satisfactory
     2     For ambient waters, a representative aliquot of a well-mixed sample may be used directly
           for analysis  If suspended solids are present m sufficient amounts to clog the nebulizer,
           the sample may be allowed to settle and the supernatant liquid analyzed directly
     3     Samples should be preserved with (11) nitric acid to a pH of 2 at the time of collection

Instrumental Parameters (General)
     1     Magnesium hollow cathode lamp
     2     Wavelength 285 2 nm
Approved for NPDES
Issued 1971
Editorial revision 1974 and  1978

                                         242 1-1

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     3.    Fuel Acetylene
     4.    Oxidant Air
     5     Type of flame Oxidizing

Notes
     1.    The interference caused by aluminum at concentrations greater than 2 mg/1 is masked
           by addition of lanthanum Sodium, potassium and calcium cause no interference at
           concentrations less than 400 mg/1
     2.    The following line may also be used
           202 5 nm Relative Sensitivity 25
     3     To cover the range of magnesium values normally observed in surface waters (0 1-20
           mg/1), it is suggested that either the 202 5 nm line be used or the burner head be rotated
           A 90' rotation of the  burner head will produce approximately one-eighth the normal
           sensitivity
     4     Data to be entered into STORET must be reported as mg/1
     5     The gravimetric method may also be used (Standard Methods, 14th Edition, p 221)

Precision and Accuracy
     1     In a single laboratory (EMSL), using distilled water spiked at concentrations of 2 1 and
           8 2 mg Mg/1 the standard deviations were 0 1 and 0 2, respectively Recoveries at
           both of these levels were 100%
                                         242 1-2

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                                   MANGANESE
              Method 243.1  (Atomic Absorption,  direct aspiration)

                                                         STORET NO.  Total  01055
                                                                     Dissolved  01056
                                                                    Suspended  01054
                                                                                       %
Optimum Concentration Range:   0 1-3 mg/1 using a wavelength of 279 5 nm
Sensitivity:     0 05 mg/1
Detection Limit:      001 mg/1

Preparation of Standard Solution
     1     Stock Solution  Carefully weigh 1 000 g of manganese metal (analytical reagent grade)
           and dissolve in  10 ml of redistilled HNO3 When solution is complete,  dilute to 1 liter
           withl%(V/V)HCl 1ml =  ImgMn (1000 mg/1)
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The procedures for preparation of the sample as given in parts 411 thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1     Manganese hollow cathode lamp
     2     Wavelength 279 5 nm
     3     Fuel Acetylene
     4     Oxidant Air
     5     Type of flame Oxidizing

Analysis Procedure
     1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual
Approved for NPDES
Issued 1971
Editorial revision 1974 and 1978

                                         243 1-1

-------
Notes
      1     For levels of manganese below 25 ug/1, either the furnace procedure, Method 243 2, or
           the Special Extraction Procedure given in part 9 2 of the Atomic Absorption Methods
           section is recommended The extraction is earned out at a pH of 4 5 to 5 The manganese
           chelate is very unstable and the analysis must be made without  delay to prevent its re-
           solution in the aqueous phase
      2     The following line may also be used
           403.1 nm Relative Sensitivity 10
      3     Data to be entered into STORET must be reported as ug/1
      4     The persulfate colonmetnc method may also be used (Standard Methods, 14th Edition,
           p225)

Precision and Accuracy
      1     An mterlaboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance and Laboratory Evaluation Branch  of EMSL  Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples The statistical results for
           manganese were as follows
                                                         Standard
Number        True Values          Mean Value           Deviation            Accuracy as
of Labs          ug/liter              ug/liter              ug/hter              % Bias

  77             426                 432                  70                    1 5
  78             469                 474                  97                    12
  71               84                  86                  26                    21
  70             106                 104                  31                  -21
  55              11                  21                  27                  93
  55              17                  21                  20                  22
                                         243 1-2

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                                   MANGANESE
              Method 243.2 (Atomic  Absorption,  furnace technique)

                                                        STORET  NO. Total 01055
                                                                     Dissolved 01056
                                                                    Suspended 01054

Optimum Concentration Range    1-30 ug/1
Detection Limit:       0 2 ug/1

Preparation of Standard Solution
     1     Stock solution  Prepare as described under "direct aspiration method"
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
     3     The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     Prepare as  described under "direct aspiration method"  Sample  solutions for analysis
           should contain 05% (v/v) HNO3

Instrument Parameters (General)
     1     Drying Time and Temp 30sec-125C
     2     Ashing Time and Temp 30sec-1000C
     3     Atomizing Time and Temp  10sec-2700C
     4     Purge Gas Atmosphere Argon
     5     Wavelength 279 5 nm
     6     Other operating parameters should  be set as specified by the particular instrument
           manufacturer

Analysis Procedure
     1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
     1     The above concentration values and instrument conditions are for a Perkin-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
Approved for NPDES
Issued  1978

                                        243 2-1

-------
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
      2    The use of background correction is recommended
      3    Nitrogen may also be used as the purge gas
      4    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      6.    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                        243 2-2

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                                     MERCURY
                  Method 245.1 (Manual Cold Vapor Technique)

                                                         STORET  NO. Total 71900
                                                                      Dissolved 71890
                                                                     Suspended 71895

     Scope and Application
     1 1  This method is applicable to drinking, surface, and saline waters, domestic and industrial
          wastes
     12  In addition to inorganic forms of mercury, organic mercurials may also be present These
          organo-mercury compounds will not respond to the cold vapor atomic absorption
          technique unless they are first broken down and converted to mercuric ions  Potassium
          permanganate oxidizes many of these compounds, but recent studies have shown that a
          number of organic mercurials, including phenyl mercuric acetate and methyl mercuric
          chloride, are only partially oxidized by this reagent Potasssmm persulfate has been
          found  to  give approximately 100% recovery  when  used  as the oxidant with these
          compounds Therefore, a persulfate oxidation  step following the addition  of  the
          permanganate has been included to insure that organo-mercury compounds, if present,
          will be oxidized to the mercuric ion before measurement A heat step is required for
          methyl mercuric chloride when present m or spiked to a natural system For distilled
          water the heat step is not necessary
     1 3  The range of the method may be varied through instrument and/or recorder expansion
          Using a 100 ml sample, a detection limit of 0 2 ug Hg/1 can be achieved, concentrations
          below this level should be reported as <  0 2 (see Appendix 112)
     Summary of Method
     2 1  The flameless A A procedure is a physical method based on the absorption of radiation at
          253 7 nm by mercury vapor The mercury is reduced to the elemental state and aerated
          from solution in a closed system The mercmy vapor passes through a cell positioned in
          the light path of an atomic absorption spectrophotometer  Absorbance (peak height) is
          measured as a function of mercury concentration and recorded in the usual manner
     Sample Handling and Preservation
     3 1  Until more conclusive data are obtained, samples should be preserved by acidification
          with nitric acid  to a pH of 2 or lower immediately at the time of collection If only
          dissolved mercury is to be determined, the sample should be filtered through an all glass
          apparatus before the acid is added  For total mercury the filtration is omitted
     Interference
     4 1  Possible interference from  sulfide is   eliminated by  the addition of  potassium
          permanganate Concentrations as high as 20 mg/1 of sulfide as sodium sulfide do not
          interfere with the recovery of added inorganic mercury from distilled water
Approved for NPDES  and SDWA
Issued 1974

                                         245 1-1

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     4 2   Copper has also been reported to interfere, however, copper concentrations as high as 10
           mg/1 had no effect on recovery of mercury from spiked samples
     43   Sea waters,  brines  and  industrial  effluents  high in  chlorides require additional
           permanganate (as much as 25 ml)  During the oxidation step, chlorides are converted to
           free chlorine which will also absorb radiation of 253 nm  Care must be taken to assure
           that free chlorine is absent before the mercury  is reduced and swept into the cell This
           may be accomplished by using an excess of hydroxylamme sulfate reagent (25 ml) In
           addition, the dead air space in the BOD bottle must be purged before the addition of
           stannous sulfate Both inorganic and organic mercury spikes have been quantitatively
           recovered from sea water using this technique
     4 4   Interference from certain volatile organic materials which will absorb at this wavelength
           is also possible  A preliminary run without reagents should determine if this type of
           interference is present (see Appendix 111)
5.    Apparatus
     5 1   Atomic Absorption Spectrophotometer (See Note 1) Any atomic absorption unit having
           an open sample presentation area in which to mount the absorption cell is suitable
           Instrument settings recommended by the particular manufacturer should be followed
           Note 1  Instruments designed specifically for the measurement of mercury using the cold
           vapor technique are commercially available and may be substituted for the atomic
           absorption Spectrophotometer
     5.2   Mercury Hollow Cathode Lamp  Westinghouse WL-22847, argon filled, or equivalent
     5 3   Recorder  Any multi-range variable speed recorder that is  compatible with the UV
           detection system is suitable
     54   Absorption Cell Standard  Spectrophotometer cells 10  cm  long, having quartz end
           windows may be used Suitable cells may be constructed from plexiglass tubing, 1" O D
           X  4-1/2" The ends are ground perpendicular to the  longitudinal  axis and  quartz
           windows (1" diameter X 1/16" thickness) are cemented in place  The cell is strapped to a
           burner for support and aligned in the light beam by use of two 2" by 2" cards One inch
           diameter holes are cut in the middle of each card, the cards are then placed over each end
           of the cell  The cell is then positioned and adjusted vertically and horizontally to give the
           maximum transmittance
     5.5   Air Pump Any peristaltic pump capable of delivering 1  liter of air per minute may be
           used A Masterflex pump with electronic speed control has been found to be satisfactory
     5 6   Flowmeter Capable of measuring an air flow of 1 liter per minute
     5 7   Aeration Tubing A straight glass frit having a coarse porosity Tygon tubing is used for
           passage of the mercury vapor from the sample bottle to the absorption cell and return
     5 8   Drying Tube  6" X 3/4" diameter tube  containing 20 g of magnesium perchlorate (see
           Note 2) The apparatus is assembled as shown in Figure 1
           NOTE 2: In place of the magnesium perchlorate drying tube, a small reading lamp with
           60W bulb may be used to prevent condensation of moisture inside the cell  The lamp is
           positioned to shine on the absorption cell maintaining the air  temperature in the cell
           about 10C above ambient
                                          245 1-2

-------
Reagents
6 1  Sulfunc Acid, Cone  Reagent grade
    611 Sulfunc acid, 0 5 N Dilute 14 0 ml of cone sulfunc acid to 1 0 liter
6 2  Nitric Acid, Cone Reagent grade of low mercury content (See Note 3)
    NOTE 3: If a high reagent blank is obtained, it may be necessary to distill the nitric acid
6 3  Stannous Sulfate  Add 25 g stannous sulfate to 250 ml of 0 5  N sulfunc acid This
    mixture is a suspension and should be stirred continuously during use (Stannous
    chloride may be used in place of stannous sulfate )
6 4  Sodium Chlonde-Hydroxylamme Sulfate Solution Dissolve 12 g of sodium chloride and
    12 g of hydroxylamme sulfate in distilled water and dilute to 100 ml  (Hydroxylamme
    hydrochlonde may be used in place of hydroxylamme sulfate )
6 5  Potassium Permanganate  5% solution, w/v Dissolve 5 g of potassium permanganate in
    100 ml of distilled water
6 6  Potassium Persulfate 5% solution, w/v Dissolve 5 g of potassium persulfate m 100 ml
    of distilled water
6 7  Stock Mercury Solution Dissolve 0 1354 g of mercuric chloride in 75 ml of distilled
    water Add 10 ml of cone nitric acid and adjust the volume to 100 0 ml 1 ml  = 1 mg
    Hg
             BUBBLER
SAMPLE  SOLUTION
IN  BOD  BOTTLE
ABSORPTION
    CELL
SCRUBBER
CONTAINING
A MERCURY
ABSORBING
MEDIA
     FIGURE 1. APPARATUS FOR  FLAMELESS
                    MERCURY  DETERMINATION
                              245 1-3

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     6 8   Working Mercury Solution Make successive dilutions of the stock mercury solution to
           obtain a working standard containing 0 1 ug per ml This working standard and the
           dilutions of the stock mercury solution should be prepared fresh daily Acidity of the
           working standard should be maintained at 0 15% nitric acid  This acid should be added
           to the flask as needed before the addition of the ahquot
7.   Calibration
     7 1   Transfer 0, 0 5, 1 0, 2 0,  5 0 and  10 0 ml aliquots of the working mercury solution
           containing 0 to 1 0 ug of mercury to a series of 300 ml BOD bottles Add enough distilled
           water to each bottle to make a total volume of 100 ml Mix thoroughly and add 5 ml of
           cone sulfunc acid (6 1) and 2 5 ml of cone nitric acid (6 2) to each bottle Add 15 ml of
           KMnO4 (6 5) solution to each bottle and allow to stand at least 15 minutes Add 8 ml of
           potassium persulfate (6 6) to each bottle and heat for 2 hours in a water bath maintmed at
           95"C Cool and add 6 ml of sodium chloride-hydroxylamine sulfate solution (6 4) to
           reduce  the  excess permanganate  When the solution has been  decolorized wait 30
           seconds, add 5 ml of the stannous sulfate solution (6 3) and immediately attach the bottle
           to the aeration apparatus forming a closed system At this point the sample is allowed to
           stand quietly without manual agitation The circulating pump,  which has previously
           been adjusted to a rate of 1 liter per minute, is allowed to run continuously (See Note 4)
           The absorbance will increase and reach maximum within 30 seconds As soon as the
           recorder pen levels off, approximately 1 minute, open the bypass valve and continue the
           aeration until the absorbance returns to its minimum value (see Note 5)  Close the bypass
           valve, remove the stopper and  frit from the BOD bottle and continue the aeration
           Proceed with the standards and construct a standard curve by plotting peak height
           versus micrograms of mercury
           NOTE 4: An open system where the mercury vapor is passed through the absorption cell
           only once may be used instead of the closed system
           NOTE 5: Because of the toxic nature of mercury vapor precaution must be taken to avoid
           its inhalation Therefore, a bypass  has been included in the system to either vent the
           mercury vapor into an exhaust hood or pass the vapor through some absorbing media,
           such as
                a)    equal volumes of 0 1 M KMnO4 and 10% H2SO4
                b)    0 25 % iodine in a 3 % KI solution
           A specially treated charcoal that  will adsorb mercury vapor is also available from
           Barnebey and Cheney, E 8th Ave andN CassidySt, Columbus, Ohio 43219,
           Cat  #580-13 or #580-22
8    Procedure
     8 1   Transfer 100 ml, or an aliquot diluted to 100 ml, containing not more than  1 0 ug of
           mercury, to a 300 ml BOD bottle  Add 5 ml of sulfunc acid (6 1) and 2 5 ml of cone
           nitnc acid  (6 2) mixing after each addition  Add 15 ml of potassium permanganate
           solution (6 5) to each sample bottle  For sewage samples additional permanganate may
           be required  Shake and add additional portions of potassium permanganate solution, if
           necessary, until the purple color persists for at least 15 minutes Add 8  ml of potassium
           persulfate (6 6) to each bottle and heat for 2 hours in a water bath at 95C Cool and add 6
                                         245 1-4

-------
           ml of sodium chlonde-hydroxylamme sulfate (6 4) to reduce the excess permanganate
           After a delay of at least 30 seconds add 5 ml of stannous sulfate (6 3) and immediately
           attach the bottle to the aeration apparatus Continue as described under Calibration
      Calculation
      9 1   Determine the peak height of the unknown from the chart and read the mercury value
           from the standard curve
      9 2   Calculate the mercury concentration in the sample by the formula
           neHR/l=  ("ZHZm\  I         l$        \
            5  e      ^ aliquot I  \  volume of aliquot in ml  I
      9 3   Report mercury concentrations as follows Below 02 ug/1, <02, between 1 and  10
           ug/1, one decimal, above 10 ug/1, whole numbers
10    Precision and Accuracy
      10 1  In a single laboratory  (EMSL),  using an  Ohio  River composite sample  with a
           background mercury concentration of 0 35 ug/1, spiked with concentrations of 1 0, 3 0
           and 4 0 ug/1, the  standard deviations  were 0 14, 0 10 and  0 08, respectively
           Standard deviation at the 0 35  level was 0 16  Percent recoveries at the three levels
           were 89, 87, and 87%, respectively
      10 2  In a joint EPA/ASTM interlaboratory study of the cold vapor technique for total
           mercury in water,  increments of organic and inorganic mercury were added to natural
           waters  Recoveries were determined by difference A statistical summary of this study
           follows
                                                         Standard
Number        True Values         Mean Value           Deviation           Accuracy as
of Labs           Hg/liter              ug/liter              ug/hter              % Bias

  76               021                0349                0276               66
  80               027                0414                0279               53
  82               051                0674                0541               32
  77               060                0709                0390               18
  82               34                 341                 149                 034
  79               41                 3 81                 1 12                -71
  79               88                 877                 369                -04
  78               96                 910                 357                -52
11   Appendix
     111 While the possibility of absorption from certain organic substances actually being present
          in the sample does exist, EMSL has not encountered such samples  This is mentioned
          only to caution the analyst of the possibility A simple correction that may be used is as
          follows  If an interference has been found to be present (4 4), the sample should be
          analyzed both by using the regular procedure and again under oxidizing conditions only,
                                         245 1-5

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           that is without the reducing reagents  The true mercury value can then be obtained by
           subtracting the two values
      112  If additional sensitivity is required, a 200 ml sample with recorder expansion may be used
           provided the instrument does not produce undue noise Using a Coleman MAS-50 with a
           drying tube of magnesium perchlorate and a variable recorder, 2 mv was set to read full
           scale. With these  conditions, and distilled water solutions of mercuric chloride at
           concentrations of  015,  0 10,  0 05  and  0 025  ug/1  the standard  deviations
           were 0 027,  0 006, 0 01 and 0 004  Percent recoveries at these levels were 107,
           83, 84 and 96%, respectively
      113  Directions for the disposal of mercury-containing wastes are given m ASTM Standards,
           Part 31, "Water", p 349, Method D3223 (1976)

                                      Bibliography

1     Kopp, J  F, Longbottom, M C and Lobnng, L B ,  "Cold Vapor Method for Determining
      Mercury", AWWA, vol 64, p 20, Jan, 1972
2     Annual Book of ASTM Standards, Part 31, "Water", Standard D3223-73, p 343 (1976)
3.     Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 156 (1975)
                                         245 1-6

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                                      MERCURY

                 Method  245.2  (Automated Cold Vapor Technique)

                                                          STORET  NO.  Total 71900
                                                                       Dissolved 71890
                                                                      Suspended 71895

 1    Scope and Application
      1 1   This method is applicable to surface waters It may be applicable to saline waters,
           wastewaters, effluents, and domestic sewages providing potential interferences are not
           present (See Interference 4)
      1 2   The working range is 0 2 to 20 0 ug Hg/1
 2    Summary of Method
      2 1   The flameless A A procedure is a physical method based on the absorption of radiation at
           253 7 nm by mercury vapor The mercury is reduced to the elemental state and aerated
           from solution The mercury vapor passes through a cell positioned in the light path of an
           atomic absorption spectrophotometer  Absorbance (peak height) is measured as a
           function of mercury concentration and recorded in the usual manner
      22   In addition to inorganic forms of mercury, organic mercurials may also be present These
           organo-mercury  compounds will not  respond to the  flameless  atomic  absorption
           technique unless they are first broken down and converted to mercunc ions Potassium
           permanganate oxidizes many of these compounds but  recent studies have shown that a
           number of organic mercurials, including phenyl mercunc acetate and methyl mercunc
           chloride, are only partially oxidized by this reagent Potassium persulfate has been found
           to give approximately 100% recovery when used as the oxidant with these compounds
           Therefore, an automated persulfate oxidation step following the automated addition of
           the  permanganate has been included to insure that  organo-mercury compounds, if
           present, will be oxidized to the mercunc ion before measurement
 3     Sample Handling and Preservation
      3  1   Until more conclusive data are  obtained, samples should be preserved by acidification
           with nitric acid to a pH of 2 or lower immediately at the time of collection(1) If only
           dissolved mercury is to be determined, the sample should be filtered before the acid is
           added For total mercury the filtration is omitted
 4     Interference (See NOTE 1)
      4 1   Some sea waters and waste-waters high in chlorides have shown a positive interference,
           probably due to the formation of free chlorine
      4 2   Interference from certain volatile organic materials which will absorb at this wavelength
           is also possible A preliminary run under oxidizing conditions, without stannous sulfate,
           would determine if this type of interference is present


Approved  for NPDES and SDWA
Issued 1974

                                         245 2-1

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     4 3   Formation of a heavy precipitate, in some wastewaters and effluents, has been reported
           upon addition of concentrated sulfunc acid If this is encountered, the problem sample
           cannot be analyzed by this method
     4 4   Samples containing solids must be blended and then mixed while being sampled if total
           mercury vlaues are to be reported
           NOTE 1: All the above interferences can be overcome by use of the Manual Mercury
           method in this manual
5.   Apparatus
     5 1   Techmcon Auto Analyzer consisting of
           511 Sampler II with provision for sample mixing
           5 1 2 Manifold
           5.13 Proportioning Pump II or III
           514 High  temperature heating  bath with  two distillation  coils (Techmcon Part
                #116-0163) in series
     5 2   Vapor-liquid separator (Figure 1)
     5 3   Absorption cell, 100 mm long, 10 mm diameter with quartz windows
     5 4   Atomic Absorption Spectrophotometer (See Note 2)  Any atomic absorption unit having
           an  open sample presentation area in which to mount the absorption cell is suitable
           Instrument settings recommended by the particular manufacturer should be followed
           NOTE 2: Instruments designed specifically for the measurement of mercury using the
           cold vapor technique are commercially available and may be substituted for the atomic
           absorption Spectrophotometer
     5 5   Mercury Hollow Cathode  Lamp Westinghouse WL-22847, argon  filled, or equivalent
     5.6   Recorder Any multi-range variable  speed recorder that is  compatible with the UV
           detection system is suitable
     5 7   Source of cooling water for jacketed mixing coil and connector A-7
     5 8   Heat lamp A small reading lamp with 60W bulb may be used to prevent condensation of
           moisture inside the cell  The  lamp is  positioned to shine on  the absorption cell
           maintaining the air temperature in the cell about 10C above ambient
6.   Reagents
     6 1   Sulfunc Acid, Cone Reagent grade
           611 Sulfunc acid, 2 N Dilute 56 ml of cone sulfunc acid to 1 liter with distilled water
           612 Sulfunc acid, 10% Dilute 100 ml cone sulfunc acid to 1 liter with distilled water
     6 2   Nitnc acid, Cone Reagent grade of low mercury content
           621 Nitnc Acid, 05% Wash Solution Dilute 5 ml of cone mtnc acid to 1 liter with
                distilled water
     6 3   Stannous Sulfate Add 50 g stannous sulfate to 500 ml of 2 N sulfunc acid (6 1 1) This
           mixture is a suspension and should be stirred continuously during use

           NOTE 3: Stannous chlonde may be used in place of stannous sulfate

     6 4   Sodium Chlonde-Hydroxylamme  Sulfate Solution  Dissolve 30 g of sodium chloride
           and 30 g of hydroxylamme sulfate in distilled water to 1 liter
                                         245 2-2

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      NOTE 4: Hydroxylamme hydrochlonde may be used m place of hydroxylamme sulfate

 6 5   Potassium Permanganate 0 5% solution, w/v Dissolve 5 g of potassium permanganate
      in 1 liter of distilled water
 6 6   Potassium Permanganate, 0 1 N Dissolve 3 16 g of potassium permanganate in distilled
      water and dilute to 1 liter
 6 7   Potassium Persulfate 05% solution, w/v Dissolve 5 g potassium persulfate in 1 liter of
      distilled water
 6 8   Stock Mercury Solution Dissolve 0 1354 g of mercuric chloride in 75 ml of distilled
      water Add 10  ml of cone nitric acid and adjust the volume to 100 0 ml  1 0 ml =  10
      mgHg
 6 9   Working Mercury Solution Make successive dilutions of the stock mercury solution
      (6 8) to obtain a working standard containing 0 1 ug per ml This working standard and
      the dilutions of the stock mercury solution should be prepared fresh daily  Acidity of the
      working standard should be maintained at 0 15% nitric acid This acid should be added
      to the flask as needed before the addition of the  aliquot From this solution prepare
      standards containing 0 2,0 5,1 0,2 0, 5 0,  10 0, 15 0 and 20 0 ug Hg/1
 6 10  Air Scrubber Solution Mix equal volumes of 0 1 N potassium permanganate (6 6) and
      10% sulfunc acid (6 1 2)
 Procedure
 7 1   Set up manifold as shown in Figure 2
 7 2   Feeding all the reagents through the system with acid wash solution (6 2 1) through the
      sample line, adjust heating bath to 105C
 7 3   Turn  on  atomic  absorption  spectrophotometer,  adjust  instrument  settings  as
      recommended by the manufacturer, align absorption cell in light path for maximum
      transmittance and place heat lamp directly over absorption cell
 7 4   Arrange working mercury standards from 0 2 to  20 0 ug Hg/1 in  sampler and  start
      sampling  Complete loading of sample tray with unknown samples
 7 5   Prepare  standard curve by plotting peak height  of processed  standards against
      concentration values  Determine concentration of  samples by comparing sample  peak
      height with standard curve
      NOTE 5: Because of the toxic nature of mercury  vapor, precaution must be taken to
      avoid its inhalation  Venting the mercury vapor into an exhaust hood or passing the
      vapor through some absorbing media such as
      a)    equal volumes of 0 1 N KMnO4 (6 6) and 10% H2SO4 (6 1 2)
      b)    0 25% iodine in a 3% KI solution, is recommended
      A specially treated charcoal that will adsorb mercury vapor is also available from
      Barnebey and Cheney, E 8th Ave and North Cassidy St, Columbus, Ohio 43219,
      Cat #580-13 or #580-22
7 6   After the analysis is complete put all lines except the H2SO4 line in distilled water to wash
      out system After flushing,  wash out the  H2SO4 line Also flush the coils in the high
      temperature heating bath by pumping stannous sulfate (6 3) through the sample lines
     followed by distilled water This will prevent build-up of oxides of manganese
                                    245 2-3

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8.    Precision and Accuracy
     81  In a single laboratory (SEWL), using distilled water standards at concentrations of 0 5,
          10,    20,   50,    100   and   200   ug   Hg/1,   the   standard   deviations
          were  004, 007,  009, 020, 040 and 0 84 ug/1, respectively
     82  In a single laboratory (SEWL), using surface water samples spiked with ten organic
          mercurials at the 10 ug/1 level, recoveries ranged from 87 to 117% Recovenes of the
          same ten organic mercurials m distilled water at the 10 ug/1 level, ranged from 92% to
          125%

                                      Bibliography

1    Wallace, R A, Fulkerson, W , Shults, W D , and Lyon, W S , "Mercury in the Environment-
     The Human Element", Oak Ridge National Laboratory, ORNL-NSF-EP-1, p 31, (January,
     1971)
2    Hatch, W R and Ott, W L, "Determination of Sub-Microgram Quantities of Mercury by
     Atomic Absorption Spectrophotometry", Anal Chem 40,2085(1968)
3    Brandenberger, H and Bader, H ,  "The Determination of Nanogram Levels of Mercury in
     Solution by  a Flameless Atomic Absorption Technique", Atomic Absorption Newsletter 6^
     101 (1967)
4    Brandenberger, H and Bader, H, "The Determination of Mercury by Flameless Atomic
     Absorption II, A Static Vapor Method", Atomic Absorption Newsletter 7^53 (1968)
5.    Goulden, P  D  and Afghan, B  K, "An Automated Method for Determining Mercury in
     Water", Techmcon, Adv  in Auto Anal  2,_p 317 (1970)
                                         245 2-4

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                                     AIR
                                     OUT
AIR  AND
SOLUTION
IN
             04 cm ID
                        7/25
07cm ID
                      l4cm
                                       SOLUTION
                                        OUT
     FIGURE 1.  VAPOR  LIQUID  SEPARATOR
                       245 2-5

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245 2-6

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                            MERCURY IN SEDIMENT

                  Method 245.5 (Manual Cold Vapor Technique)

      Scope and Application
      1 1   This procedure"' measures total mercury (organic f inorganic) in soils, sediments,
           bottom deposits and sludge type materials
      1 2   The range of the method is 0 2 to 5 ug/g The range may be extended above or below the
           normal range by increasing or decreasing sample size or through instrument and
           recorder control
      Summary of Method
      21   A weighed portion of the sample is digested in aqua regia for 2 minutes at 95C, followed
           by oxidation with potassium permanganate  Mercury m the digested sample is then
           measured by the conventional cold vapor technique
      22   An alternate digestion"' involving the use of an autoclave is described in (8 2)
      Sample Handling and Preservation
      3 1   Because of the extreme sensitivity of the analytical procedure and the omnipresence of
           mercury, care must be taken to avoid extraneous contamination Sampling devices and
           sample containers should be ascertained to be free of mercury, the sample should not be
           exposed to any  condition in the laboratory that may result in contact or air-borne
           mercury contamination
      3 2   While the sample may be analyzed without drying, it has been found to  be more
           convenient to analyze a dry sample Moisture may be driven off in a drying oven at a
           temperature of 60C No mercury losses have been observed by using this drying step
           The dry sample should be pulverized and thoroughly mixed before  the aliquot is
           weighed
      Interferences
      4 1   The same types of interferences that may occur in water samples are  also possible with
           sediments, i e , sulfides, high copper, high chlorides, etc
      4 2   Volatile materials which absorb at 253 7 nm will cause a positive interference In order to
           remove any interfering volatile materials, the dead air space in the BOD bottle should be
           purged before the addition of stannous sulfate
      Apparatus
      5 1   Atomic Absorption  Spectrophotometer (See Note 1)   Any atomic absorption unit
           having an  open sample presentation area in  which to mount the absorption  cell is
           suitable Instrument settings recommended by the particular manufacturer should be
           followed
           NOTE 1  Instruments designed specifically for the measurement of mercury using the
           cold vapor technique are commercially available and may be substituted for the atomic
           absorption Spectrophotometer
Issued 1974

                                         245 5-1

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5 2   Mercury Hollow Cathode Lamp Westmghouse WL-22847, argon filled, or equivalent
5 3   Recorder- Any multi-range variable speed recorder that is compatible with the UV
      detection system is suitable
5.4   Absorption  Cell  Standard spectrophotometer cells 10 cm long, having quartz end
      windows may be used Suitable cells may be constructed from plexiglass tubing, 1" O D
      X 4-1/2"  The ends are ground perpendicular to the longitudinal axis and quartz
      windows (1" diameter X 1/16" thickness) are cemented in place Gas inlet and outlet
      ports (also of plexiglass but  1/4" O D ) are attached approximately 1/2" from each end
      The cell is strapped to a burner for support and aligned in the light beam to give the
      maximum transmittance
      NOTE 2: Two 2" X 2" cards with one inch diameter holes may be placed over each end
      of the cell to assist in positioning the cell for maximum transmittance
5.5   Air Pump Any peristaltic pump capable of delivering 1 liter of air per minute may be
      used  A Masterflex pump with electronic speed control has been found to be satisfactory
      (Regulated compressed air can be used in an open one-pass system )
5 6   Flowmeter Capable of measuring an air flow of 1 liter per minute
5.7   Aeration Tubing Tygon tubing is used for passage of the mercury vapor from the sample
      bottle to the absorption cell and return Straight glass tubing terminating in a coarse
      porous frit is used for sparging air into the sample
5 8   Drying Tube 6" X 3/4" diameter tube containing 20 g of magnesium perchlorate (See
      Note 3) The apparatus is assembled as shown in the accompanying diagram
      NOTE 3: In place of the magnesium perchlorate drying tube, a small reading lamp with
      60W bulb may be used to prevent condensation of moisture inside the cell  The lamp is
      positioned to shine on the absorption cell maintaining the  air temperature in the cell
      about 10C above ambient
Reagents
6 1   Aqua Regia Prepare immediately before use by carefully adding three volumes of cone
      HC1 to one volume of cone HNO3
6 2   Sulfunc Acid, 0 5 N Dilute  14 0 ml of cone sulfunc acid to 1 liter
6 3   Stannous Sulfate Add 25 g  stannous sulfate to 250 ml of 0 5 N sulfunc acid (6 2) This
      mixture is a suspension and should be stirred continuously during use
6,4   Sodium Chlonde-Hydroxylamme Sulfate Solution   Dissolve 12 g of sodium chloride
      and 12 g of hydroxylamme sulfate in distilled water and dilute to 100 ml
      NOTE 4: A 10% solution of stannous  chloride may be substituted for (6 3) and
      hydroxylamme hydrochlonde may be used in place of hydroxylamme sulfate in (6 4)
65   Potassium Permanganate 5% solution, w/v Dissolves g of potassium permanganate in
      100 ml of distilled water
6 6   Stock Mercury Solution  Dissolve 0 1354  g of mercuric chloride in  75 ml of distilled
      water Add 10 ml of cone nitric acid and adjust the volume to 100 0 ml  1 0 ml = 10
      mgHg
6 7   Working Mercury Solution  Make successive dilutions of the stock  mercury solution
      (6 6) to obtain a working standard containing 0 1 ug/ml This working standard and the
      dilution of the stock mercury solutions should be prepared fresh daily Acidity of the
                                    245 5-2

-------
      working standard should be maintained at 0 15% nitric acid This acid should be added
      to the flask as needed before the addition of the aliquot
 Calibration
 7 1   Transfer 0, 0 5, 1 0, 2 0, 5 0 and 10 ml ahquots of the working mercury solution (6 7)
      containing 0 to 1 0 ug of mercury to a series of 300 ml BOD bottles Add enough distilled
      water to each bottle to make a total volume of 10 ml Add 5 ml of aqua regia (6 1) and
      heat 2 minutes in a water bath at 95C Allow the sample to cool and add 50 ml distilled
      water and 15 ml of KMnO4 solution (6 5) to each bottle and return to the water bath for
      30 minutes Cool and add 6 ml of sodium chlonde-hydroxylamme sulfate solution (6 4)
      to reduce the excess permanganate  Add 50 ml of distilled water Treating each bottle
      individually,  add 5 ml of stannous sulfate solution (6 3) and immediately attach the
      bottle to the aeration apparatus At this point, the sample is allowed to stand quietly
      without manual agitation The circulating pump, which has previously been adjusted to
      rate of 1 liter per minute, is allowed to run continuously  The absorbance,  as exhibited
      either on the spectrophotometer or the recorder, will increase and reach maximum
      within 30 seconds As soon as the recorder pen levels off, approximately 1 minute, open
      the bypass value and continue the aeration until the absorbance returns to its minimum
      value (See Note 5) Close the bypass value, remove the fritted tubing from  the BOD
      bottle and continue the aeration Proceed with the standards and construct a standard
      curve by plotting peak height versus microgiams of mercury
      NOTE 5: Because of the toxic nature of mercury vapor precaution must be taken to avoid
      its inhalation Therefore, a bypass  has been included in the system to either vent the
      mercury vapor into an exhaust hood or pass the vapor through some absorbing media,
      such as
      a)    equal volumes of 0 1 N KMnO4 and 10% H2SO4
      b)    0 25% iodine in a 3% KI solution
      A specially treated charcoal  that  will absorb  mercury vapor  is also available from
      Barnebey and Cheney, E 8th Ave , and North Cassidy St, Columbus, Ohio 43219,
      Cat  #580-13 or #580-22
Procedure
8 1    Weigh triplicate 0 2 g portions of dry sample and place in bottom of a BOD bottle Add 5
      ml of distilled water and 5 ml of aqua regia (6 1)  Heat 2 minutes in a water bath at 95C
      Cool, add 50 ml distilled water and 15 ml potassium permanganate solution (6 5) to each
      sample bottle Mix thoroughly and place in the water bath for 30 minutes at 95C Cool
      and  add 6 ml  of sodium chloride-hydroxylamme sulfate (6 4)  to  reduce the excess
      permanganate Add 55 ml of distilled water Treating each bottle individually, add 5 ml
      of stannous sulfate (6 3) and immediately attach the bottle to the aeration apparatus
      Continue as described under (71)
8 2    An alternate  digestion procedure employing an autoclave may  also be used In this
      method 5 ml of cone  H2SO4 and 2 ml of cone HNO3 are added to the 0 2 g of sample  5
      ml of saturated KMnO4 solution is added and the bottle covered with a piece  of
      aluminum foil The samples are autoclaved at 121C and  15 Ibs  for 15 minutes  Cool,
     make up to a volume of 100 ml with distilled water and add 6 ml of sodium  chlonde-
                                    245 5-3

-------
          hydroxylamme sulfate solution (6 4) to reduce the excess permanganate Purge the dead
          air space and continue as described under (7 1)

9.    Calculation
     9 1  Measure the peak height of the unknown from the chart and read the mercury value from
          the standard curve
     9 2  Calculate the mercury concentration in the sample by the formula
          .,_/_ _   ugHgm the aliquot
          ugng/g - wt of the aliquot in gr
                             aliquot in gms

     9 3  Report mercury concentrations as follows  Below 0 1 ug/gm, <0 1, between 0 1 and 1
          ug/gm,  to the nearest 001 ug, between 1  and 10 ug/gm, to nearest 0 1  ug, above 10
          ug/gm, to nearest ug
10   Precision and Accuracy
     10.1 The following standard deviations on replicate sediment samples were recorded at the
          indicated levels, 0 29 ug/g 0 02 and 0 82 ug/g 0 03 Recovery of mercury at these
          levels, added as methyl mercuric chloride, was 97% and 94%, respectively

                                      Bibliography

1.    Bishop, J N, "Mercury in Sediments", Ontano Water Resources Comm, Toronto, Ontario,
     Canada, 1971
2    Salma, M , private communication, EPA Cal/Nev Basin Office, Almeda, California
                                        245 5-4

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                                  MOLYBDENUM

               Method 246.1  (Atomic Absorption,  direct aspiration)

                                                         STORET No. Total 01062
                                                                     Dissolved 01060
                                                                    Suspended 01061

Optimum Concentration Range:   1-40 mg/1 using a wavelength of 313 3 nm
Sensitivity:     0 4 mg/1
Detection Limit:      0 1 mg/1

Preparation of Standard Solution
     1     Stock Solution  Dissolve  1 840 g of ammonium molybdate (NH4)6Mo7O244H2O
           (analytical reagent grade) in deiomzed distilled water and dilute to 1 liter 1 ml = 1 mg
           Mo (1000 mg/1)
     2     Aluminum nitrate solution Dissolve 139 g aluminum nitrate, A1(NO3)39H2O, in 150 ml
           of deiomzed distilled water, heat to effect solution Allow to cool and make up to 200 ml
     3     Prepare dilutions of the stock molybdenum solution to be used as calibration standards
           at the time of analysis The calibration standards should be prepared using the same type
           of acid and at the same concentration as will result in the sample to be analyzed either
           directly or after processing  To each 100 ml of standard and sample alike, add 2 ml of the
           aluminum nitrate solution

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The  procedures for preparation of the sample  as given in parts 411  thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1     Molybdenum hollow cathode lamp
     2     Wavelength 3133nm
     3     Fuel Acetylene
     4     Oxidant Nitrous Oxide
     5     Type of flame Fuelnch
Approved for NPDES
Issued  1974
Editorial revision  1978

                                        246 1-1

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Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual

Interferences
      1     With the recommended nitrous oxide-acetylene flame, interferences of calcium and other
           ions may be controlled by adding 1000 mg/1 of a refractory metal such as aluminum
           [Anal  Chem Acta 44, 437 (1969)] This should be done to both samples and standards
           alike

Notes
      1     Data to be entered into STORET must be reported as ug/1
     2     For concentrations  of molybdenum below 0 2 mg/1,  the furnace procedure, Method
           246 2, is recommended

Precision and Accuracy
      1     In a single laboratory (EMSL), using a mixed  industrial-domestic waste effluent at
           concentrations of 0 30, 15 and 7 5 mg Mo/1, the standard deviations were 0 007,
           0 02 and  0 07, respectively Recoveries at these levels were 100%, 96% and 95%,
           respectively
                                         246 1-2

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                                 MOLYBDENUM

              Method 246.2  (Atomic Absorption, furnace technique)

                                                        STORET  No.  Total 01062
                                                                    Dissolved 01060
                                                                   Suspended 01061

Optimum Concentration Range:   3-60 ug/1
Detection Limit:      1 ug/1

Preparation of Standard Solution
     1    Stock solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as described under "direct aspiration method" Sample solutions for analysis
          should contain 05% (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-1400C
     3    Atomizing Time and Temp 15sec-2800C
     4    Purge Gas Atmosphere Argon
     5    Wavelength  313 3 nm
     6    Other operating parameters should be set as  specified by the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure", part 9 3 of the
          Atomic Absorption Methods section of this manual
Approved for NPDES
Issued 1978
                                        246 2-1

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Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite
      2     Background correction may be required if the sample contains high dissolved solids
      3     The use of nitrogen as a purge gas is not recommended
      4.    For every sample matrix analyzed, verfication is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         246 2-2

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                                      NICKEL
              Method 249.1  (Atomic Absorption,  direct aspiration)

                                                        STORET NO.  Total 01067
                                                                     Dissolved 01065
                                                                    Suspended 01066

Optimum Concentration Range:   0 3-5 mg/1 using a wavelength of 232 0 nm
Sensitivity.     015 mg/1
Detection Limit:      0 04 mg/1

Preparation of Standard Solution
     1    Stock Solution Dissolve 4 953 g of nickel nitrate, Ni(NO3)26H2O (analytical reagent
          grade) in deiomzed distilled water  Add 10 ml of cone  nitric acid and dilute to 1 liter
          with deiomzed distilled water  1 ml  =  1 mgNi( 1000 mg/1)
     1    Prepare dilutions of the stock nickel solution to be used as calibration standards at the
          time of analysis The calibration standards should be prepared using the same type of
          acid and at the same concentration as will result in the sample to be analyzed either
          directly or after processing

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    The procedures for preparation of the sample as given  in parts 411 thru 4 1 4 of the
          Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1    Nickel hollow cathode lamp
     2    Wavelength 232 0 nm
     3,    Fuel Acetylene
     4    Oxidant Air
     5    Type of Flame Oxidizing

Analysis Procedure
     1    For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
          Absorption Methods section of this manual
Approved for  NPDES
Issued 1974
Editonal revision 1978

                                        249 1-1

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Interferences
      1     The 352 4 nm wavelength is less susceptible to spectral interference and may be used
           The calibration curve is more linear at this wavelength, however, there is some loss of
           sensitivity

Notes
      1     For levels of nickel below 100 ug/1, either the Special Extraction Procedure, given in
           part 9 2 of the Atomic Absorption Methods section or the furnace technique, Method
           249 2, is recommended
      2     Data to be entered into STORET must be reported as ug/1
      3     The heptoxime method may also be used (Standard Methods, 14th Edition, p 232)

Precision and Accuracy
      1     In a  single laboratory (EMSL), using a  mixed industrial-domestic waste effluent at
           concentrations of 0 20,1 0 and 5 0 mg Ni/1, the standard deviations were 0011, 0 02
           and 004, respectively  Recoveries at  these levels  were 100%, 97%  and 93%,
           respectively
                                         249 1-2

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                                      NICKEL
              Method 249.2  (Atomic Absorption, furnace technique)

                                                        STORET NO. Total  01067
                                                                     Dissolved  01065
                                                                    Suspended  01066

Optimum Concentration Range:    5-50 ug/1
Detection Limit:      1 ug/1

Preparation of Standard Solution
     1    Stock solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to used for "standard additions"
    1 3    The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as described under "direct aspiration method" Sample solutions for analysis
          should contain 05% (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30 sec-800C
     3    Atomizing Time and Temp  10sec-2700C
     4    Purge Gas Atmosphere Argon
     5    Wavelength  232 0 nm
     6    Other  operating parameters should be  set as  specified by the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual

Notes
     1    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
          2100, based  on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
Approved for NPDES
Issued  1978

                                        249 2-1

-------
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
     2    The use of background correction is recommended
     3    Nitrogen may also be used as the purge gas
     4    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1    Precision and accuracy data are not available at this time
                                         249 2-2

-------
                                      OSMIUM
              Method  252.1  (Atomic Absorption,  direct aspiration)

                                                               STORET NO.  Total*

Optimum Concentration Range:   2-100 mg/1 using a wavelength of 290 9 nm
Sensitivity:      1 mg/1
Detection Limit:      0 3 mg/1

Preparation of Standard Solution
     1    Stock Solution  A standard AAS solution of osmium tetroxide, OsO4, 1000 mg/1 m
          aqueous matrix is available from Alfa Products, Beverly, Massachusetts 01915
          Cat #88084
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis The calibration standards should be prepared to contain \% (v/v) HNO3 and
          l%(v/v)H2SO4

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Transfer a representative 100 ml aliquot of the well mixed sample to a Griffin beaker and
          add 1 ml of cone distilled HNO3 Place the beaker on a steam bath or hot plate and warm
          for 15 minutes  Cool the beaker and filter to remove insoluble material that could clog
          the atomizer Add 1 ml of cone  H2SO4 and adjust the volume back to 100 ml The sample
          is now ready for analysis

Instrumental Parameters (General)
     1    Osmium hollow cathode lamp
     2    Wavelength 290 9 nm
     3    Fuel  Acetylene
     4    Oxidant  Nitrous oxide
     5    Type of flame Fuel rich

Analysis Procedure
     1    For the analysis procedure and calculation, see "Direct Aspiration", part 9 1 of  the
          Atomic Absorption Methods section of this manual

*Not Assigned

Approved for NPDES
Issued  1976
Technical revision 1978

                                        252 1-1

-------
Notes
     1     Osmium tetroxide, the usual commercial form, is very volatile and highly toxic Care
           should be exercised when working with this compound
     2     For concentrations of osmium below 0 5 mg/1 the furnace procedure, Method 252 2, is
           recommended

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                        252 1-2

-------
                                     OSMIUM
              Method 252.2  (Atomic Absorption,  furnace  technique)

                                                                  STORET NO Total*

Optimum Concentration Range.    50-500 ug/1
Dectection Limit     20 ug/1

Preparation of Standard Solution
     1    Stock solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 1 % (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as described under "direct aspiration method",  except omit the addition of
          H2SO4 on the final volume adjustment  Sample solutions for analysis should contain 1%
          (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-105C
     2    Ashing Time and Temp See NOTE 3 below
     3    Atomizing Time and Temp 10 sec-2700C
     4    Purge Gas Atmosphere Argon
     5    Wavelength 290 9 nm
     6    Other operating parameters  should be set as specified by  the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual

Notes
     1    Osmium tetroxide, the usual commercial form, is very volatile and highly toxic Care
          should be exercised when working with this compound

*Not Assigned

Approved for NPDES
Issued 1978

                                        252 2-1

-------
     2.    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite
     3     Since OSO4 volatilizes near 150C, the allowable ashing temperature must be verified m
           the sample matrix being analyzed
     4.    The use of background correction is recommended
     5     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption  Methods
           section of this manual)
     6     If method of standard addition is required, follow the procedure given earlier m part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         252 2-2

-------
                                    PALLADIUM
               Method  253.1  (Atomic Absorption,  direct aspiration)

                                                         STORET NO.  Total  01210

Optimum Concentration Range:    05-15 mg/1 using a wavelength of 247 6 nm
Sensitivity.      0 25 mg/1
Detection Limit:      0 1 mg/1

Preparation of Standard Solution
      1     Stock Solution  Dissolve 0 1000 g of palladium wire m a minimum volume of aqua regia
           and evaporate just to dryness Add 5 ml cone HC1 and 25 ml deiomzed water and warm
           until dissolution is complete Dilute to 100 ml with deiomzed water (1 ml = 1 mg Pd)
      2     A standard A AS solution of palladous chloride, PdCl2, 1000 mg/1 in aqueous matrix is
           available from Alfa Products, Beverly, Massachusetts 01915
           Cat #88085
      3     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared to contain 05% (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Transfer a representative aliquot of the well mixed sample to a Griffin beaker and add 3
           ml of cone  distilled HNO3 Place the beaker on a steam bath and evaporate to near
           dryness Cool the beaker and cautiously add a 5 ml portion of aqua regia (See below for
           preparation of aqua regia f) Cover the beaker with a watch glass and return to the steam
          bath Continue heating the covered beaker for 30 minutes Remove cover and evaporate
           to near dryness Cool and add 1 1 redistilled HNO3 (1 ml per 100 ml dilution) Wash
           down the beaker walls and watch glass with distilled water and filter the sample to
           remove silicates and other insoluble material that could clog the atomizer Adjust the
          volume to some predetermined value based on the  expected metal concentration The
          sample is now ready for analysis
fAqua regia-prepare immediately before use by carefully adding three volume of
cone HC1 to one volume of cone  HNO3

Approved for NPDES
Issued  1976
Technical revision  1978

                                        253 1-1

-------
Instrumental Parameters (General)
      1     Palladium hollow cathode lamp
      2     Wavelength 247 6 nm
      3.    Fuel Acetylene
      4     Oxidant Air
      5     Type of flame Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual

Notes
      1     For concentrations of palladium below 0 25 mg/1, the furnace procedure, Method 253 2,
           is recommended

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                        253 1-2

-------
                                    PALLADIUM
              Method  253.2 (Atomic Absorption, furnace technique)

                                                         STORET NO. Total  01210

Optimum Concentration Range:   20-400 ug/1
Detection Limit:      5 ug/1

Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as described under "direct aspiration method" Sample solution for analysis
           should contain 0 5%(v/v) HNO3

Instrument Parameters (General)
      1     Drying Time and Temp  30sec-125C
      2     Ashing Time and Temp  30sec-1000C
      3     Atomizing Time and Temp 10sec-2800C
      4     Purge Gas Atmosphere  Argon
      5     Wavelength 247 6 nm
      6     Other  operating parameters should be set as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use  of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atonuzation can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings

Approved for NPDES
Issued 1978
                                        253 2-1

-------
     2     The use of background correction is recommended
     3     Nitrogen may also be used as the purge gas
     4.    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
                                                                                     i

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                          253 2-2

-------
                                     PLATINUM
               Method 255.1 (Atomic  Absorption, direct aspiration)

                                                               STORET  NO. Total*

Optimum Concentration Range:   5-75 mg/1 using a wavelength of 265 9 nm
Sensitivity:      2 mg/1
Detection Limit:      0 2 mg/1

Preparation of Standard Solution
      1     Stock Solution Dissolve 0 1000 g of platinum metal in a minimum volume of aqua regia
           and evaporate just to dryness Add 5 ml HC1 and 0 1 g NaCl and again evaporate just to
           dryness Dissolve the residue in 20 ml of (1 1) HCl and dilute to 100 ml with deiomzed
           water (1 ml = ImgPt)
      2     A standard AAS solution of chloroplatimc acid, H2PtCl6) 1000 mg/1 in aqueous matrix
           is available from Alfa Products, Beverly, Massachusetts 01915
           Cat  #88086
      3     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared to contain 0 5%(v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Transfer a representative aliquot of the well mixed sample to a Griffin beaker and add 3
           ml of cone  distilled HNO3  Place the beaker on a steam  bath and evaporate to near
           dryness Cool the beaker and cautiously add a 5 ml portion  of aqua regia  (See below for
           preparation of aqua regia f)  Cover the beaker with a watch  glass and return to the steam
           bath  Continue heating the covered beaker for 30 minutes Remove cover and evaporate
           to near dryness Cool and add 1 1 distilled HNO3 (1 ml per 100 ml dilution)  Wash down
           the beaker walls  and watch glass  with distilled water and  filter the sample to remove
           silicates and other insoluble material that could clog the atomizer Adjust the volume to
           some predetermined value based on the expected metal concentration The sample is now
           ready for analysis
fAqua regia-prepare immediately before use by carefully adding three volumes of cone HCl
to one volume of cone  HNO3

*Not Assigned

Approved for NPDES
Issued  1976
Technical revision 1978

                                        255 1-1

-------
Instrumental Parameters (General)
      1     Platinum hollow cathode lamp
      2     Wavelength 265 9 nm
      3     Fuel Acetylene
      4     Oxidant Air
      5     Type of flame Oxidizing

Analysis Procedure
      1     For analysis procedure and calculation, see "Direct Aspiration", part 9 1 of the Atomic
           Absorption Methods section of this manual

Notes                        ,
      1     For concentrations of platinum below 1.0 mg/1, the furnace procedure, Method 255 2, is
           recommended

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                        255 1-2

-------
                                     PLATINUM
              Method  255.2  (Atomic Absorption,  furnace  technique)

                                                               STORET NO. Total*

 Optimum Concentration Range:   01-2 mg/1
 Detection Limit:      0 02 mg/1

 Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calibration standard should be diluted to contain 0 5% (v/v) HNO3

 Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain 0 5% (v/v)HNO3

 Instrument Parameters (General)
      1     Drying Time and Temp 30sec-125C
      2     Ashing Time and Temp 30sec-1300C
      3     Atomizing Time and Temp 10sec-2800C
      4     Purge Gas Atmosphere Argon
      5     Wavelength  265 9 nm
      6     Other operating parameters should be set as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based  on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can

*Not  Assigned

Approved for NPDES
Issued 1978

                                        255 2-1

-------
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
      2    The use of background correction is recommended
      3    Nitrogen may also be used as the purge gas
      4,    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         255 2-2

-------
                                     POTASSIUM
               Method  258.1  (Atomic Absorption, direct aspiration)

                                                          STORET NO.  Total  00937
                                                                      Dissolved  00935
                                                                     Suspended  00936

 Optimum Concentration Range:    01-2 mg/1 using a wavelength of 766 5 nm
 Sensitivity:      0 04 mg/1
 Detection Limit:      0 01 mg/1

 Preparation of Standard Solution
      1     Stock Solution Dissolve 0 1907 g of KC1 (analytical reagent grade), dried at 110C, in
           deiomzed distilled water and make up to 1 liter 1 ml  = 0 10 mg K (100 mg/1)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

 Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     For the analysis of total potassium in domestic and industrial effluents, the procedures
           for the determination of total metals as given in parts 413 and 4 1 4 of the Atomic
           Absorption Methods section of this manual have been found to be satisfactory
      2     For ambient waters, a representative aliquot of a well  mixed sample may also be used
           directly for analysis If suspended solids are present in sufficient amounts to clog the
           nebulizer, the sample may be allowed to settle and the supernatant liquid analyzed
           directly

 Instrumental Parameters (General)
      1     Potassium hollow cathode lamp
      2    Wavelength 766 5 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Slightly oxidizing
Approved for  NPDES
Issued 1971
Editorial revision 1974

                                         258 1-1

-------
Analysis Procedure
      1     For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods section of this manual

Notes
      1     In air-acetylene or other high temperature flames ( > 2800C), potassium can experience
           partial  lomzation which indirectly affects absorption sensitivity The presence of other
           alkali salts in the sample can reduce this lomzation and thereby enhance analytical
           results  The lomzation suppressive effect of sodium is small if the ratio of Na to K is
           under 10 Any enhancement due to sodium can be stabilized by adding  excess sodium
           (1000 ug/ml) to both sample  and standard solutions  If more  stringent  control  of
           lomzation is required, the addition of cesium should be considered  Reagent blanks
           should be analyzed to correct for potassium impurities m the buffer stock
     2     The 404 4 nm line may also be used This line has a relative sensitivity of 500
     3     To cover the range of potassium values normally observed in  surface waters (0 1-20
           mg/1), it is suggested that the burner head be rotated A 90 rotation of the burner head
           provides approximately one-eighth the normal sensitivity
     4.    The flame photometric or colonmetnc methods may also be used (Standard Methods,
           14th Edition, p 234 & 235)
     5     Data to be entered into STORET must be reported as mg/1

Precision and Accuracy
      1     In a single laboratory (EMSL), using distilled water samples spiked at concentrations of
           1 6  and  6 3 mg K/l  The standard  deviations were  0 2 and 0 5, respectively
           Recoveries at these levels were 103% and 102%, respectively
                                          258 1-2

-------
                                      RHENIUM
               Method  264.1  (Atomic Absorption,  direct aspiration)
                                                          * *     ,           i
                                                                STORET NO. Total*

 Optimum Concentration Range:   50-1000 mg/1 using a wavelength of 346 0 nm
 Sensitivity:     15 mg/1
 Detection Limit:      5 mg/1

 Preparation of Standard Solution
      1    Stock solution  Dissolve 1 554 g of potassium perrhenate, KReO4, in 200 ml deiomzed
           water Dilute to 1 liter with 1% (v/v) H2SO4 (1 ml =  1 mg Re)
      2    A standard AAS solution of ammonium perrhenate, NH4ReO4, 1000 mg/1 in aqueous
           matrix is available from Alfa Products, Beverly, Massachussetts.01915
           Cat #88089
      3    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using 1 % (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see p'art 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Transfer a representative 100 ml aliquot of the well mixed sample to a Griffin beaker and
           add 1 ml of cone distilled HNO3 Place the beaker on a steam bath or hot plate and warm
           for 15 minutes Cool and filter to remove insoluble material that could clog the atomizer
           Adjust the volume back to 100 ml  The sample is now ready for analysis

 Instrumental Parameters (General)
      1    Rhenium hollow cathode lamp
      2    Wavelength 346 Onm
      3    Fuel Acetylene
      4    Oxidant Nitrous Oxide
      5    Type of flame Fuel rich

 Analysis Procedure
      1    For the analysis procedure and the calculation, see "direct aspiration" part 9,1 of the
           Atomic Absorption Methods section of this manual

 *Not Assigned
Issued 1976
Technical revision  1978

                                        264 1-1

-------
Notes
     1    For concentrations of rhenium below 10 mg/1, the furnace procedure, Method 264 2, is
          recommended
Precision and Accuracy
     1    Precision and accuracy data are not available at this time
                                         264 1-2

-------
                                      RHENIUM
               Method 264.2  (Atomic Absorption,  furnace  technique)

                                                                   STORET NO. Total*

 Optimum Concentration Range   0 5-5 mg/1

 Detection Limit      0 2 mg/1

 Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calibration standards should be diluted to contain 1 % (v/v) HNO3

 Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain l%(v/v) HNO3

 Instrument Parameters (General)
      1     Drying Time and Temp 30sec-125C
      2     Ashing Time and Temp 30sec-300C
      3     Atomizing Time and Temp 10 sec-2800C
      4     Purge Gas Atmosphere Argon
      5     Wavelength  346 Onm
      6     Other operating parameters should be set as specified by the particular instrument
           manufacturer

 Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
*Not  Assigned


Issued 1978

                                        264 2-1

-------
Notes
     1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite
     2     Background correction may be required if the sample contains high dissolved solids
     3     Since many rhenium compounds volatilize near 300C, the allowable ashing temperature
           should be verified in the sample matrix being analyzed
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         264 2-2

-------
                                      RHODIUM
               Method 265.1 (Atomic  Absorption, direct aspiration)

                                                                STORET  NO. Total*

 Optimum Concentration Range:   1-30 mg/1 using a wavelength of 343 5 nm
 Sensitivity:     0 3 mg/1
 Detection Limit:      0 05 mg/1

 Preparation of Standard Solution
      1    Stock Solution Dissolve 0 3768 g of ammonium chlororhodite, (NH4)3RhCl6H2O, in a
           minimum volume of 10% (v/v) HC1 and dilute to 100 ml with 10% HC1 (1 ml = Img
           Rh)
      2    A standard AAS solution of rhodium trichloride, RhCl3, 1000 mg/1 in aqueous matrix is
           available from Alfa Products, Beverly, Massachusetts 01915
           Cat #88090
      3    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared to contain 05% (v/v) HNO3

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Transfer a representative aliquot of the well mixed sample to a Griffin beaker and add 3
           ml of cone  distilled HNO3 Place the beaker on a steam bath and evaporate to near
           dryness  Cool the beaker and cautiously add a 5 ml portion of aqua regia  (See below for
           preparation of aqua regia f) Cover the beaker with a watch glass and return to the steam
           bath Continue heating the covered beaker for 30 minutes Remove cover and evaporate
           to near dryness Cool and add  1 1 distilled HNO3 (1 ml per 100 ml dilution) Wash down
           the beaker walls and watch glass with distilled water and filter the sample to remove
           silicates and other insoluble material that could clog the atomizer Adjust the volume to
           some predetermined value based on the expected metal concentration  The sample is now
           ready for analysis
fAqua regia-prepare immediately before use by carefully adding three volumes
of cone HC1 to one volume of cone  HNO3

*Not Assigned

Approved for NPDES
Issued 1976
Technical revision 1978
                                         265 1-1

-------
Instrumental Parameters (General)
      1     Rhodium hollow cathode lamp
      2     Wavelength 343 5 nm
      3     Fuel Acetylene
      4     Oxidant Air
      5.    Type of flame Oxidizing

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods section of this manual

Notes
      1     For concentrations of rhodium below 0 2 mg/1, the furnace procedure, Method 265 2, is
           recommended

Precision and Accuracy
      1.     Precision and accuracy data are not available at this time
                                        265 1-2

-------
                                      RHODIUM
               Method 265.2 (Atomic Absorption,  furnace  technique)
                                                               STORET NO. Total*
 Optimum Concentration Range:    20-400 ug/1
 Detection Limit:      5 ug/1

 Preparation of Standard Solution
      1    Stock solution Prepare as described under "direct aspiration method"
     , 2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3    The calibration standard should be diluted to contain 05% (v/v) HNO3

 Sample Preservation
      1    For sample handling  and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Prepare as described  under "direct aspiration method"  Sample solutions for analysis
           should contain 05% (v/v) HNO3

 Instrument Parameters (General)
      1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-1200C
     3    Atomizing Time and Temp 10sec-2800C
     4    Purge Gas Atmosphere Argon
     5    Wavelength 343 5 nm
     6    Other operating parameters  should be set as specified by the particular instrument
           manufacturer

 Analysis Procedure
     1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
*Not  Assigned

Approved for NPDES
Issued 1978
                                        265 2-1

-------
Notes
      1.    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite
     2.    Background correction may be required if the sample contains high dissolved solids
     3     The use of nitrogen as a purge gas is not recommended
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
     1,    Precision and accuracy data are not available at this time
                                         265 2-2

-------
                                    RUTHENIUM
                            >          "                                  *
               Method 267.1  (Atomic Absorption,  direct aspiration)

                                                                STORET  NO.  Total*
                                    >     ,
 Optimum Concentration Range:   1-50 mg/1 using a wavelength of 349 9 nm
^Sensitivity:     0 5 mg/1
 Detection Limit:      0 2 mg/1

 Preparation of Standard Solution
      1    Stock Solution Dissolve 0 2052 g of ruthenium chloride, RuCl3, in a minimum volume of
           20% (v/v) HC1 and dilute to 100 ml with 20% HC1 (1 ml =  1 mg Ru)
      2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using 1 % (v/v) HC1

 Sample Preservation
      1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1    Transfer a representative  100 ml aliquot of the well mixed sample to a Griffin beaker and
           add 2 ml of distilled (11) HC1 Place the beaker on a steam bath or hot plate and warm at
           95C for 15 minutes Cool the beaker and filter the sample to remove insoluble material
           that could clog the atomizer Adjust the volume back to 100 ml The sample is now ready
           for analysis

 Instrumental Parameters (General)
      1    Ruthenium hollow cathode lamp
      2    Wavelength 349 9 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Oxidizing

 Analysis Procedure
      1    For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods section of this manual
 *Not Assigned

 Approved for NPDES
 Issued 1976
 Technical revision 1978

                                         267 1-1

-------
Notes
     1     For concentrations of ruthenium below 0 5 mg/1, the furnace procedure, Method 267 2,
           is recommended

Precision and Accuracy
     1.    Precision and accuracy data are not available at this time
                                        267 1-2

-------
                                   RUTHENIUM
              Method 267.2 (Atomic  Absorption, furnace technique)
                                                               STORET NO.  Total*
Optimum Concentration Range* 0 1-2 mg/1
Detection Limit.      0 02 mg/1

Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     Using distilled (11) HC1, the calibration standards should be diluted to contain 1 % (v/v)
           HC1

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as described under "direct aspiration method" Sample solutions for  analysis
           should contain 1% (v/v) HC1

Instrument Parameters (General)
      1     Drying Time and Temp  30sec-125C
      2     Ashing Time and Temp  30sec-^00C
      3     Atomizing Time and Temp  10sec-2800C
      4     Purge Gas Atmosphere  Argon
      5     Wavelength 349 9 nm
      6     Other operating parameters should be set as specified by  the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
*Not  Assigned

Approved for NPDES
Issued 1978
                                        267 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite
      2     Background correction may be required if the sample contains high dissolved solids
      3.    Nitrogen may also be used as the purge gas
      4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption  Methods
           section of this manual)
      5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         267 2-2

-------
                                     SELENIUM

              Method  270.2  (Atomic Absorption,  furnace  technique)
                                                         STORET NO. Total 01147
                                                                      Dissolved 01145
                                                                     Suspended 01146

Optimum Concentration Range:   5-100 ug/1
Detection Limit:      2 ug/1

Preparation of Standard Solution
      1     Stock Selenium Solution Dissolve 0 3453 g of selenous acid (actual assay 94 6% H2SeO3)
           in deiomzed distilled water and make up to 200 ml 1 ml    1 mg Se (1000 mg/1)
      2     Nickel Nitrate Solution, 5% Dissolve 24 780 g of ACS reagent grade Ni(NO3)26H2O in
           deiomzed distilled water and make up to 100 ml
      3     Nickel Nitrate Solution,  1%  Dilute 20 ml of the  5%  nickel nitrate to 100 ml with
           deiomzed distilled water
      4     Working Selenium Solution Prepare dilutions of the  stock solution to be used as
           calibration standards at the time of analysis Withdraw appropriate aliquots of the stock
           solution, add 1 ml of cone HNO3, 2 ml of 30% H2O2 and 2 ml of the 5%  nickel nitrate
           solution Dilute to 100 ml with deiomzed distilled water

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Transfer 100 ml of well-mixed sample to a 250 ml Griffin beaker, add 2 ml of 30% H2O2
           and sufficient cone  HNO3 to result in an acid concentration of 1 %(v/v) Heat for  1 hour
           at 95C or until the volume is slightly less than 50 ml
      2     Cool and bring back to 50 ml with deiomzed distilled water
      3     Pipet 5 ml of this digested solution into a 10-ml volumetric flask, add 1 ml of the 1%
           nickel nitrate solution and dilute to 10 ml with deiomzed distilled water The sample is
           now ready for injection into the furnace NOTE If solubihzation or digestion  is not
           required adjust the HNO3 concentration of the sample to  1% (v/v) and add 2 ml of 30%
           H2O2 and 2 ml of 5% nickel nitrate to each 100 ml of sample  The volume  of the
           calibration standard should be adjusted with deiomzed distilled water to  match the
           volume change of the sample
Approved for NPDES and SDWA
Issued 1978

                                        270 2-1

-------
Instrument Parameters
      1    Drying time and temperature 30 sec 125C
      2    Charring time and temperature  30 see 1200C
      3.    Atomizing time and temperature 10 sec @ 2700C
      4    Purge Gas Atmosphere Argon                                            ,   , > '
      5    Wavelength  196 Onm
      6    Other operating parameters should be set as specified by  the particular instrument
           manufacturer                                                         '

Analysis Procedure
      1    For the analysis procedure and the calculation see "Furnace  Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual

Notes
      1.    The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, purge gas interrupt and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time  periods than the
           above recommended settings
      2.    The use of background correction is recommended
      3    Selenium analysis suffers interference from chlorides (> 800 mg/1) and sulfate (> 200
           mg/1) For the analysis of industrial effluents and samples with concentrations of sulfate
           from 200 to 2000 mg/1, both samples and standards should be prepared to contain 1%
           nickel
      4    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5  2 1 of the Atomic Absorption Methods
           section of this manual)
      5    For quality control requirements and optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
      6    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      7    Data to entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Using a sewage treatment  plant  effluent containing <2  ug/1  and spiked with a
           concentration of 20 ug/1, a recovery of 99% was obtained
      2    Using a series of industrial waste effluents spiked at a 50 ug/1 level, recoveries ranged
           from 94 to 112%
      3    Using a 0 1% nickel nitrate solution as a synthetic matrix with selenium concentrations
           of 5,  10, 20, 40, 50, and 100 ug/1, relative standard deviations of 14 2,  11 6, 9 3, 7 2, 6 4
           and 41%, respectively, were obtained at the 95% confidence level
                                         270 2-2

-------
     4     In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
           of  5,  10,  and 20 ug  Se/1,  the  standard deviations were 06, 04,  and 05,
           respectively Recoveries at these levels were 92%, 98%, and 100%, respectively

Reference:
     "Determining Selenium in Water, Wastewater, Sediment and Sludge By Flameless Atomic
     Absorption Spectroscopy", Martin, T D , Kopp, J F and Ediger, R D Atomic Absorption
     Newsletter 14,109 (1975)
                                         270 2-3

-------
                                    SELENIUM

              Method  270.3 (Atomic Absorption, gaseous hydride)

                                                        STORET NO.  Total  01147
                                                                    Dissolved  01145
                                                                   Suspended  01146

     Scope and Application
     1 1   The  gaseous  hydride method  determines  inorganic  selenium  when present  in
          concentrations at or above 2 ug/1 The method is applicable to drinking water and most
          fresh and saline waters, in the absence of high concentrations of chromium, cobalt,
          copper, mercury, molybdenum, nickel and silver
     Summary of Method
     2 1   Selenium in the sample is reduced from the + 6 oxidation state to the +4 oxidation state
          by the addition of SnCl2 Zinc is added to the acidified sample, producing hydrogen and
          converting the selenium to the hydride, SeH2 The gaseous selenium hydride is swept into
          an argon-hydrogen flame of an  atomic absorption spectrophotometer The working
          range of the method is 2-20 ug/1 using the 196 0 nm wavelength
     Comments
     31   In analyzing drinking water and most surface and ground waters, interferences are rarely
          encountered  Industrial  waste samples should be  spiked with a  known amount of
          selenium to establish adequate recovery
     3 2   Organic forms of selenium must be converted  to an inorganic form  and organic matter
          must be oxidized before beginning the analysis  The oxidation procedure given in method
          206 5 (Standard Methods, 14th Ed 404B, p 285, Procedure 4 1) should be used
     3 3   For sample handling and  preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual
     3 4   For quality control requirements and optional recommendations  for use in drinking
          water analyses,  see part 10 of the Atomic Absorption Methods section of this manual
     35   Data to be entered into STORET must be reported as ug/1
     Precision and Accuracy
     4 1   Ten replicate solutions of selenium oxide at the 5, 10 and 15 ug/1 level were analyzed by
          a single laboratory  Standard deviations at these levels were  06,  11 and  2 9 with
          recoveries of 100, 100 and 101%  (Caldwell, J   S , Lishka, R   J, and McFarren, E F ,
          "Evaluation of a Low-Cost Arsenic and Selenium Determination at Microgram per Liter
          Levels", JAWWA,vol 65, p 731,Nov  1973)
Approved for NPDES and SDWA
Issued  1974
                                        270 3-1

-------
5.   References
     5.1   Except for the perchloric acid step, the procedure to be used for this determination is
           found in
           Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 159,
           Method 301A(VII), (1975)
                                        270 3-2

-------
                                       SILVER

              Method 272.1  (Atomic Absorption, direct aspiration)

                                                         STORET NO.  Total 01077
                                                                      Dissolved 01075
                                                                     Suspended 01076

Optimum Concentration Range:   0 1-4 mg/1 using a wavelength of 328 1 nm
Sensitivity:     0 06 mg/1
Detection Limit:       001 mg/1

Preparation of Standard Solution
     1     Stock Solution Dissolve 1  575 g of AgNO3 (analytical reagent grade) in deiomzed
           distilled water, add 10 ml cone HNO3 and make up to 1 liter  1 ml =  1 mg Ag (1000
           mg/1)
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using nitric acid and at the same
           concentration as  will result in the sample to be analyzed either directly or after
           processing
     3     Iodine Solution, 1 N  Dissolve 20 grams of potassium iodide, KI (analytical reagent
           grade) in  50  ml of deiomzed distilled water, add 127 grams of iodine, I2 (analytical
           reagent grade) and dilute to 100 ml Store in a brown bottle
     4     Cyanogen Iodide (CNI) Solution To 50 ml of deiomzed distilled water add 4 0 ml cone
           NH4OH, 6 5 grams KCN, and 5 0 ml of 1 0 NI2 solution Mix and dilute to 100 ml with
           deiomzed distilled water Fresh solution should be prepared every two weeks a)

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The procedures for preparation of the sample as given in parts 411 thru 4 1 3 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory,
           however, the residue must be taken up in dilute nitric acid rather than hydrochloric to
           prevent precipitation of AgCl
Approved for  NPDES and SDWA
Issued 1971
Editorial revision 1974
Technical revision 1978
                                         272 1-1

-------
 Instrumental Parameters (General)
      1.    Silver hollow cathode lamp
      2.    Wavelength 328 1 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Oxidizing

 Analysis Procedure
      1    For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods section of this manual

 Notes
      1    For levels of silver below 30 ug/1, either the Special Extraction Procedure, given in part
           9 2 of the Atomic Absorption Methods section or the furnace procedure, Method 272 2,
           is recommended
      2    Silver nitrate standards are light sensitive Dilutions of the stock should be discarded
           after use as concentrations below 10 mg/1 are not stable over long periods of time
      3    If absorption to container walls or the formation of AgCl is suspected, make the sample
           basic using cone NH4OH and add 1 ml of (CNI) solution per 100 ml of sample  Mix the
           sample and allow to stand for 1 hour before proceeding with the analysis (1)
      4    The 338 2 nm wavelength may also be used This has a relative sensitivity of 2
      5    Data to be entered into STORET must be reported as ug/1
Precision and Accuracy
     1    In a round-robin study reported by Standard Methods, a synthetic sample containing 50
          ug Ag/1 was analyzed by 50 laboratories with a reported standard deviation of 8 8 and
          a relative error 10 6%

References
     1.   "The Use of Cyanogen Iodide (CNI) as a Stabilizing Agent for Silver in Photographic
          Processing Effluent Sample", Owerbach, Daniel, Photographic Technology Division,
          Eastman Kodak Company, Rochester, N Y 14650
     2    Standard Methods for Examination of Water and Wastewater, 14th Edition, p 148,
          Method 301A
                                         272 1-2

-------
                                      SILVER

              Method 272.2  (Atomic Absorption, furnace technique)

                                                        STORET NO.  Total 01077
                                                                    Dissolved 01075
                                                                   Suspended 01076

Optimum Concentration Range:    1-25 ug/1
Detection Limit:      0 2 ug/1

Preparation of Standard Solution
     1    Stock Solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as described under "direct aspiration method" Sample solutions for analysis
          should contain 0 5% (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-400C
     3    Atomizing Time and Temp 10sec-2700C
     4    Purge Gas Atmosphere Argon
     5    Wavelength  328 1 nm
     6    Other operating parameters  should be set as specified by the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual
Approved  for NPDES and SDWA
Issued  1978
                                        272 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
      2     Background correction may be required if the sample contains high dissolved solids
      3     The use of hahde acids should be avoided
      4     If adsorption to container walls or formation of AgCl is suspected, see NOTE 3 under the
           Direct Aspiration Method 272  1
      5     For every sample matrix analyzed,  verification is necessary to determine that method of
           standard addition is not required  (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      6     For quality control requirements and  optional recommendations for use in drinking
           water analyses, see part 10 of the Atomic Absorption Methods section of this manual
      7     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods  section of this manual
      8     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy:
      1.     In a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked at concentrations
           of 25, 50, and 75 ug  Ag/1, the standard deviations were 04,  07, and +09,
           respectively  Recoveries at these levels were 94%, 100% and 104%, respectively
                                        272 2-2

-------
                                       SODIUM

               Method 273.1 (Atomic Absorption, direct  aspiration)

                                                         STORET  NO. Total 00929
                                                                      Dissolved 00930
                                                                     Suspended 00928

Optimum Concentration Range   0 03-1 mg/1 using a wavelength of 589 6 nm
Sensitivity       0015 mg/1
Detection Limit       0 002 mg/1

Preparation of Standard Solutions
     1     Stock Solution  Dissolve 2 542  g of NaCl (analytical reagent grade), dried at 140C, in
           deiomzed distilled water and make up to 1 liter 1 ml =  1  mg Na (1000 mg/1)
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
     1     For sample handling  and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     For the analysis of total sodium in domestic and industrial effluents, the procedures for
           the determination  of total metals  as given in parts 413  and 4 1 4 of the Atomic
           Absorption Methods section of this manual have been found to be satisfactory
     2     For ambient waters, a representative aliquot of a well-mixed sample may be used directly
           for analysis If suspended solids are present in sufficient amounts to clog the nebulizer,
           the sample may be allowed to settle and the supernatant liquid analyzed directly

Instrumental Parameters (General)
     1     Sodium hollow cathode lamp
     2     Wavelength 589 6 nm
     3     Fuel Acetylene
     4     Oxidant  Air
     5     Type of flame Oxidizing
Approved for  NPDES
Issued  1971
Editorial revision 1974

                                        273 1-1

-------
Analysis Procedure
      1     For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods, section of this manual

Notes
      1     The 330 2 nm resonance line of sodium, which has a relative sensitivity of 185, provides a
           convenient way to avoid the need to dilute more concentrated solutions of sodium
     2     Low-temperature flames increase sensitivity by reducing the extent of lomzation of this
           easily ionized metal lomzation may also be controlled by adding potassium (1000 mg/1)
           to both standards and samples
     3     Data to be entered into STORET must be reported as mg/1
     4     The flame photometric method  may also be used (Standard Methods,  14th Edition, p
           250)

Precision and Accuracy
     1     In a single laboratory (EMSL), using distilled water samples spiked at levels of 8 2 and 52
           mgNa/1, the standard deviations were  0 1 and  0 8, respectively Recoveries at these
           levels were 102% and 100%
                                         273 1-2

-------
                                 United States
                                 Environmental Protection
                                 Agency
                                 Environmental Monitoring and
                                 Support Laboratory
                                 Cincinnati OH 45268
                                 Research and Development
vvEPA
Test  Method
                                 Sodium  (Atomic
                                 Absorption, furnace
                                 technique)Method  273.2
                                Optimum Concentration Range  1-30
                                /"9/L
                                Detection Limit 0 2 /yg/L
                                Preparation of Standard Solution
                                  1 Stock solution Prepare as
                                    described under direct
                                    aspiration method
                                  2 Prepare dilutions of the stock
                                    solution to be used as calibration
                                    standards at the time of analysis
                                    These solutions are also to be
                                    used for  standard additions
                                  3 The calibration standard should
                                    be diluted to contain 0 5% (v/v)
                                    HNO3

                                Sample Preservation
                                  1 For sample handling and preser-
                                    vation  see part 4 1  of the Atomic
                                    Absorption Methods section of
                                    this manual
                                Sample Preparation
                                  1 Prepare as described under  di-
                                    rect aspiration method  Sample
                                    solutions for analysis should
                                    contain 0 5% (v/v) HNO3

                                Instrument Parameters (General)
                                  1 Drying Time and Temp 30 sec @
                                    125C
                                  2 Ashing Time and Temp 30 sec @
                                    250C
                                  3 Atomizing Time and Temp  10 sec
                                    @ 2000C
                                  4 Purge Gas atmosphere Argon
                                  5 Wavelength 589 6  nm
                                  6 Other operating parameters
                                    should be set as specified by the
                                    particular instrument
                                    manufacturer

                                Analysis Procedure
                                  1  For the analysis procedure and
                                    the calculation, see  Furnace
                                    Procedure  9 3 of the Atomic
                                    Absorption method section of
                                    this manual
                                Notes
                                  1  The above concentration values
                                    and instrument conditions are
                                    for a Perkm-Elmer HGA-2100
                                    based on the use of a 20 fjL
                                    injection continuous flow purge
                                    gas and non-pyrolytic graphite
                                    Smaller size furnace devices or
                                    those employing faster rates of
                                    atomization can be operated
                                    using lower atomization
                                    temperatures for shorter time
                                    periods than the above
                                    recommended settings
                                  2  Samples containing
                                    concentrations higher than those
                                    given in the optimum range
                                    should be analyzed by either the
                                    direct aspiration method (Method
                                    273 1) or the flame photometric
                                    method (Std Methods 14th
                                    Edition p 250)
                                  3  Nitrogen  may also be used as
                                    the purge gas
                                  4  For every sample matrix
                                    analyzed, verification is
                                    necessary to determine that
                                    method of standard addition is
                                    not required (see 5 2 1 of
                                    the Atomic Absorption method
                                    section of this manual)
                                  5  If method of standard addition  is
                                    required  follow the procedure
                                    given earlier in 8 5 of the
                                    Atomic Absorption methos
                                    section of this manual
                                2732 1
                                                       Dec 1982

-------
  6  Data to be entered into STORE!
     must be reported as //g/L

Precision and Accuracy
  1  Precision and accuracy data are
     not available at this time
                                    Dec  1982                     2732-2

-------
                                     THALLIUM

               Method  279.1  (Atomic Absorption,  direct aspiration)

                                                         STORET NO.  Total 01059
                                                                      Dissolved 01057
                                                                     Suspended 01058

 Optimum Concentration Range.    1-20 mg/1 using a wavelength of 276 8 nm
 Sensitivity      0 5 mg/1
 Detection Limit.      0 1 mg/1

 Preparation of Standai d Solution
      1     Stock Solution  Dissolve 1 303 g of thallium nitrate, T1NO3 (analytical reagent grade) m
           deiomzed distilled water Add  10 ml  of cone  nitric  acid and dilute  to 1 liter  with
           deiomzed distilled water 1ml  = 1 mgTl( 1000 mg/1)
      2     Prepare dilutions of the stock thallium solution to be used as calibration standards at the
           time of analysis The calibration standards should be prepared using nitric acid and at the
           same concentration as will result in the sample to be analyzed either directly or  after
           processing

 Sample Preservation
      1     For sample handling and preservation,  see part 4 1 of the Atomic Absorption Methods
           section of this manual

 Sample Preparation
      1     The procedures for preparation  of the  sample as given in parts 4 1 1  thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory if
           HC1 is omitted

 Instrumental Parameters (General)
      1    Thallium hollow cathode lamp
      2    Wavelength 276 8 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Oxidizing
Approved for  NPDES
Issued  1974
Technical revision  1978
                                         279 1-1

-------
Analysis Procedure
      1     For the analysis procedure and the'calculation, see "Direct Aspiration", part 9 1 of the
           Atomic Absorption Methods section of this manual
              "                  i     t  i      J     '            l
Notes
      1     For concentrations of thallium below 0 2 mg/1, the furnace procedure, Method 279 2, is
           recommended
     2     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     In  a single laboratory  (EMSL), using a mixed  industrial-domestic  waste  effluent at
           concentrations of 0 60, 3 0 and 15 mg Tl/1, the standard deviations were 0 018, 6 05
           and 02,  respectively  Recoveries  at these levels  were 100%,  98% and 98%,
           respectively
                                         279 1-2

-------
                                    THALLIUM

              Method 279.2 (Atomic Absorption,  furnace  technique)

                                                        STORET NO. Total  01059
                                                                     Dissolved  01057
                                                                    Suspended  01058

Optimum Concentration Range:   5-100 ug/1
Detection Limit:      1 ug/1

Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as described under "direct aspiration method" Sample solutions for analysis
           should contain 05% (v/v) HNO3

Instrument Parameters (General)
      1     Drying Time and Temp 30 sec 125C
      2     Ashing Time and Temp 30 sec @ 400C
      3     Atomizing Time and Temp  10 sec @ 2400C
      4     Purge Gas Atmosphere Argon
      5     Wavelength 276 8 nm
      6     Other operating parameters should be  set  as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued  1978
                                        279 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a, Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time  periods than the
           above recommended settings
      2     The use of background correction is recommended
      3     Nitrogen may also be used as the purge gas
      4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         279 2-2

-------
                                          TIN

               Method 282.1 (Atomic Absorption, direct  aspiration)

                                                         STORET NO. Total 01102
                                                                      Dissolved 01100
                                                                    Suspended 01101

Optimum Concentration Range:   10-300 mg/1 using a wavelength of 286 3 nm
Sensitivity.      4mg/l
Detection Limit       0 8 mg/1

Preparation of Standard Solution
      1     Stock Solution Dissolve 1 000 g of tin metal (analytical reagent grade) in 100 ml of cone
           HC1 and dilute to 1 liter with deiomzed distilled water 1 ml =  1 mg Sn (1000 mg/1)
      2     Prepare dilutions of the stock tin solution to be used as calibration standards at the time
           of analysis  The calibration standards should be prepared using the same type of acid and
           at the same concentration as will result in the sample to be analyzed either directly or
           after processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The  procedures for preparation of the sample as given in parts 411 thru 4 1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
      1     Tin hollow cathode lamp
      2     Wavelength 286 3 nm
      3     Fuel  Acetylene
      4     Oxidant Nitrous Oxide
      5     Type of flame Fuel rich

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Direct Aspiration", part 9 1  of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued 1974
Editorial revision 1978

                                        282 1-1

-------
Notes
     1    For concentrations of tin below 2 mg/1, the furnace procedure, Method 282 2, is
          recommended
     2    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1    In a single laboratory (EMSL), using a mixed industrial-domestic waste effluent spiked
          at concentrations of 4 0, 20 and 60 mg Sn/1, the standard deviations were 0 25, 0 5
          and 05, respectively Recoveries at these levels were  96%,  101%,  and 101%,
          respectively
                                         282 1-2

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                                          TIN
              Method 282.2  (Atomic Absorption,  furnace  technique)
                                                         STORET NO. Total 01102
                                                                      Dissolved 01100
                                                                     Suspended 01101
Optimum Concentration Range:
Detection Limit:       5 ug/1
                               20-300 ug/1
Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
      3     The calibration standard should be diluted to contain 2% (v/v) HNO3

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     The procedures for preparation of the sample as given in parts 4 1  1 thru 4 1 3 of the
           Atomic Absorption Methods section of this manual  should be followed including the
           addition  of sufficient  1 1  HC1 to dissolve the digested residue for the analysis of
           suspended or total tin  The sample solutions used for  analysis should contain 2% (v/v)
           HNO3

Instrument Parameters (General)
      1     Drying Time and Temp 30sec-125C
      2     Ashing Time and Temp 30sec-600C
      3     Atomizing Time and Temp 10sec-2700C
      4     Purge Gas Atmospere  Argon
      5     Wavelength 224 6 nm
      6     Other operating parameters should be set as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued 1978
                                        282 2-1

-------
Notes
     1     The above concentration values and instrument conditions are for a Perkin-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
     2     The use of background correction is recommended
     3     Nitrogen may also be used as the purge gas
     4     Tin analysis is sensitive to chloride concentration  If chloride concentration presents a
           matrix problem or causes a loss previous to atomization, add an excess of 5 mg of
           ammonium nitrate to the  furnace and ash using a ramp necessary or with incremental
           steps until the recommended ashing temperature is reached Extended ashing times have
           been reported to improve precision
     5.    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     6     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     7     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         282 2-2

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                                     TITANIUM

               Method 283.1 (Atomic Absorption, direct  aspiration)

                                                         STORET  NO. Total 01152
                                                                      Dissolved 01150
                                                                     Suspended 01151

Optimum Concentration Range:   5-100 mg/1 using a wavelength of 365 3 nm
Sensitivity:      2 mg/1
Detection Limit:      0 4 mg/1

Preparation of Standard Solution
      1     Stock solution Dissolve 1 000 g of titanium metal (powder or small pieces) in 200 ml
           6N HC1 Heat to near 100olC|to effect dissolution  Cool and dilute to 1 liter with
           deiomzed distilled water  (1 ml = 1 mg Ti (1000 mg/1)
     2     Potassium chloride solution  Dissolve 95 g potassium chloride, KC1, in distilled water
           and make up to 1 liter
     3     Prepare dilutions of the stock titanium solution to be used as calibration standards at the
           time of analysis  The calibration standards should  be prepared using the same type of
           acid and at the same concentration as will result m the sample to be analyzed either
           directly or after processing To each 100 ml of standard and sample alike, add 2 ml of
           potassium chloride solution

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The procedures for preparation of the sample as given in parts 411 thru 4 1 3 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory
           with  the following  modification  For  processing total and  suspended titanium,
           concentrated H2SO4 (2 ml per 100 ml of final dilution) must be added m addition to the
           nitric  acid  Reflux  the  sample  adding  additional nitric  acid  as needed  When
           solubilization  is  complete, heat  until  the appearance of SO3 fumes Cool  and add
           sufficient distilled nitric acid so that the final dilution contains 05% (v/v) HNO3

Instrumental Parameters (General)
     1     Titanium hollow cathode lamp
     2     Wavelength 365 3 nm
     3     Fuel  Acetylene


Approved for NPDES
Issued  1974

                                         283 1-1

-------
     4    Oxidant Nitrous Oxide
     5    Type of flame Fuel rich
              (                                i         f       \
Analysis Procedure
     1.   For the analysis procedure and the calculation, see "Direct Aspiration" part 9 1 of the
          Atomic Absorption Methods section of this manual

Interferences
     1    A number of elements increase the sensitivity of titanium  To control this problem,
          potassium  (1000  mg/1)  must be  added to standards  and samples alike   [Atomic
          Absorption Newsletter 6,_p 86 (1967)]

Notes
     1    For concentrations of titanium below 1 0 mg/1, the furnace procedure, Method 283 2, is
          recommended
     2.   Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1    In a single laboratory (EMSL), using a mixed industrial-domestic waste effluent spiked
          at concentrations of 2 0, 10 and 50 mg Ti/1, the standard deviations were  0 07, 0 1
          and 0 4, respectively Recovenes at these levels were 97%, 91% and 88%, respectively
                                        283 1-2

-------
                                     TITANIUM

              Method  283.2 (Atomic Absorption, furnace technique)

                                                        STORET  NO. Total 01152
                                                                     Dissolved 01150
                                                                    Suspended 01151

Optimum Concentration Range:   50-500 ug/1
Detection Limit:      10 ug/1

Preparation of Standard Solution
      1     Stock solution Prepare as described under "direct aspiration method"
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis
      3     The calibration standards should be prepared using the same type of acid and at the same
           concentration  as will result in the  sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1     Prepare as described  under "direct aspiration method" Sample solutions for analysis
           should contain 05% (v/v) HNO3

Instrument Parameters (General)
      1     Drying Time and Temp  30sec-125C
      2     Ashing Time and Temp  30sec-1400C
      3     Atomizing Time and Temp  15 sec-2800C
      4     Purge Gas Atmosphere Argon
      5     Wavelength 365 4 nm
      6     Other operating parameters should be set as specified by the particular instrument
           manufacturer

Analysis Procedure
      1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued  1978

                                       283 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow  purge gas and pyrolytic
           graphite
      2     Background correction may be required if the sample contains high dissolved solids
      3     Because of possible chemical interactions, nitrogen should not be used as the purge gas
      4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
      5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      6.    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                          283 2-2

-------
                                    VANADIUM
                                                                         f ^

               Method 286.1 (Atomic Absorption, direct aspiration)

                                                         STORET NO. Total  01087
                                                                     Dissolved  01085
                                                                    Suspended  01086

Optimum Concentration Range:   2-100 mg/1 using a wavelength of 318 4 nm
Sensitivity:     0 8 mg/1
Detection Limit*      0 2 mg/1

Preparation of Standard Solution
     1     Stock Solution Dissolve  1 7854 g of vanadium pentoxide, V2O5 (analytical  reagent
           grade) in 10 ml of cone nitric acid and dilute to 1 liter with deiomzed distilled water 1
           ml =  ImgV (1000 mg/1)
     2     Aluminum nitrate solution Dissolve 139 g aluminum nitrate, A1(NO3)39H2O, in 150 ml
           of deiomzed distilled water, heat to effect solution Allow to cool and make up to  200 ml
     3     Prepare dilutions of the stock vanadium solution to be used as calibration standards at
           the time of analysis The calibration standards should be prepared using the same type of
           acid and at the same concentration as will result in the sample to be analyzed either
           directly or after processing To each 100 ml of standard and sample alike, add 2 ml of the
           aluminum, nitrate solution

Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     The procedures for preparation of the sample as given in parts 411 thru 4  1 4 of the
           Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters (General)
     1     Vanadium hollow cathode lamp
     2     Wavelength 3184nm
     3     Fuel Acetylene
     4     Oxidant Nitrous oxide
     5     Type of flame Fuel rich
Approved for NPDES
Issued  1974
                                        286 1-1

-------
Analysis Procedure
      1     For the analysis procedure and the calculation, see "Direct Aspiration" part 9 1 of the
           Atomic Absorption Methods section of this manual

Interferences
      1     It has been reported that  high concentrations of aluminum and titanium increase the
           sensitivity of vanadium This interference can be controlled by adding excess aluminum
           (1000 ppm) to both samples and standards  [Talanta^S, 871 (1968)]

Notes
      1     For concentrations of vanadium below 0 5 mg/1, the furnace procedure, Method 286 2,
           is recommended
      2     The gallic acid colonmetnc method may also be used (Standard Methods, 14th Edition,
           p260)
      3     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     In a single laboratory (EMSL), using a mixed industrial-domestic waste effluent spiked
           at concentrations of 2 0, 10 and 50 mg V/l, the standard deviations were  0 10,  0 1
           and 02,  respectively  Recoveries at  these levels  were 100%,  95% and  97%,
           respectively
                                         286 1-2

-------
                                                I       i
                      VANADIUM

    '                              j
Method 286.2 (Atonic  Absorption,  furnace  technique)
                                                        STORET NO. Total 01087
                                                   '                  Dissolved 01085
                                                                    Suspended 01086

Optimum Concentration Range:   10-200 ug/l
Detection Limit:      4 ug/l
     '                 i               f
Preparation of Standard Solution
     1     Stock solution  Prepare as described under "direct aspiration method"
     2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis These solutions are also to be used for "standard additions"
     3     The calibration standard should be, diluted to contain 05% (v/v) HNO3
                                                                     ?
Sample Preservation
     1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
     1     Prepare as described under  "direct aspiration method"  Sample solution for analysis
           should contain 05% (v/v) HNO3

Instrument Parameters (General)
     1     Drying Time and Temp 30sec-125C
     2     Ashing Time and Temp 30sec-1400C
     3     Atomizing Time and Temp  15sec-2800C
     4     Purge Gas Atmosphere Argon
     5     Wavelength  318 4 nm
     6     Other operating parameters should be set as specified by the particular  instrument
           manufacturer

Analysis Procedure
     1     For the analysis procedure and the calculation, see "Furnace Procedure" part 9 3 of the
           Atomic Absorption Methods section of this manual
Approved for NPDES
Issued  1978
                                        286 2-1

-------
Notes
      1     The above concentration values and instrument conditions are for a Perkm-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atomization can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
     2     Background correction may be required if the sample contains high dissolved solids
     3     Because of possible chemical interaction, nitrogen should not be used as the purge gas
     4     For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required (see part 5 2 1 of the Atomic Absorption Methods
           section of this manual)
     5     If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
     6     Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
     1     Precision and accuracy data are not available at this time
                                         286 2-2

-------
                                         ZINC

               Method 289.1 (Atomic Absorption, direct  aspiration)

                                                         STORET NO. Total 01092
                                                                      Dissolved 01090
                                                                     Suspended 01091

Optimum Concentration Range:   0 05-1 mg/1 using a wavelength of 213 9 nm
Sensitivity:      0 02 mg/1
Detection Limit:      0 005 mg/1

Preparation of Standard Solution
      1     Stock Solution Carefully weigh 1 00 g of zinc metal (analytical reagent grade) and
           dissolve cautiously in 10 ml HNO3  When solution is complete make up to 1 liter with
           deiomzed distilled water 1 ml = 1 mg Zn (1000 mg/1)
      2     Prepare dilutions of the stock solution to be used as calibration standards at the time of
           analysis The calibration standards should be prepared using the same type of acid and at
           the same concentration as will result in the sample to be analyzed either directly or after
           processing

Sample Preservation
      1     For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
           section of this manual

Sample Preparation
      1    The  procedures for preparation of the sample as given in parts 4 1 1 thru 4 1 4 of the
          Atomic Absorption Methods section of this manual have been found to be satisfactory

Instrumental Parameters
      1    Zinc hollow cathode lamp
      2    Wavelength 213 9 nm
      3    Fuel Acetylene
      4    Oxidant Air
      5    Type of flame Oxidizing

Analysis Procedure
      1    For the analysis procedure and the calculation, see "direct aspiration" part 9 1  of the
          Atomic Absorption Methods section of this manual


Approved for NPDES
Issued 1971
Editorial  revision 1974

                                         289 1-1

-------
Notes
     1     High levels of silicon may interfere
     2     The air-acetylene flame absorbs about 25% of the energy at the 2139 nm line
     3     The sensitivity may be increased by the use of low-temperature flames
     4     Some sample container cap liners can be a source of zinc contamination To circumvent
           or avoid this problem, the use of polypropylene caps is recommended
     5     The dithizone colonmetnc method may also be used (Standard Methods, 14th Edition, p
           265)
     6     For concentrations of zinc below 001 mg/1, either the Special Extraction Procedure
           given in part 9 2 of the Atomic Absorption Methods section or the furnace procedure,
           Method 289 2, is recommended
     7     Data to entered into Storet must be reported as ug/1

Precision and Accuracy
     1.    An mterlaboratory study on trace metal analyses by atomic absorption was conducted by
           the Quality Assurance  and  Laboratory Evaluation Branch of EMSL  Six synthetic
           concentrates containing varying levels of aluminum, cadmium, chromium, copper, iron,
           manganese, lead and zinc were added to natural water samples The statistical results for
           zinc were as follows
Number
of Labs

  86
  89
  82
  81
  62
  61
True Values
  ug/hter

  281
  310
   56
   70
    7
   11
Mean Value
  ug/hter

  284
  308
   62
   75'
   22
   17
Standard
Deviation
 ug/hter

  97
 114
  28
  28
  26
  18
Accuracy as
  % Bias

    12
  -07
   113
    66
  206
  566
                                        289 1-2

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                                        ZINC

              Method 289.2  (Atomic Absorption, furnace technique)

                                                        STORET NO. Total 01092
                                                                    Dissolved 01090
                                                                   Suspended 01091

Optimum Concentration Range:   0 2-4 ug/1
Detection Limit:      0 05 ug/1

Preparation of Standard Solution
     1    Stock Solution Prepare as described under "direct aspiration method"
     2    Prepare dilutions of the stock solution to be used as calibration standards at the time of
          analysis These solutions are also to be used for "standard additions"
     3    The calibration standard should be diluted to contain 05% (v/v) HNO3

Sample Preservation
     1    For sample handling and preservation, see part 4 1 of the Atomic Absorption Methods
          section of this manual

Sample Preparation
     1    Prepare as described  under "direct aspiration method"  Sample solution for analysis
          should contain 05% (v/v) HNO3

Instrument Parameters (General)
     1    Drying Time and Temp 30sec-125C
     2    Ashing Time and Temp 30sec-400C
     3    Atomizing Time and Temp 10sec-2500C
     4    Purge Gas Atmosphere Argon
     5    Wavelength 2139 nm
     6    Other operating  parameters should be set as specified by the particular instrument
          manufacturer

Analysis Procedure
     1    For the analysis procedure and the calculation, see  "Furnace Procedure" part 9 3 of the
          Atomic Absorption Methods section of this manual
Approved for NPDES
Issued 1978
                                        289 2-1

-------
 Notes
      1    The above concentration values and instrument conditions are for a Perkin-Elmer HGA-
           2100, based on the use of a 20 ul injection, continuous flow purge gas and non-pyrolytic
           graphite Smaller size furnace devices or those employing faster rates of atonuzation can
           be operated using lower atomization temperatures for shorter time periods than the
           above recommended settings
      2    The use of background correction is recommended
      3    Nitrogen may also be used as the purge gas
      4.    The analysis of zinc by the graphite furnace is extremely sensitive and very subject to
           contamination from the work area, reagents, and pipet tips Since all these factors affect
           the precision and accuracy, zinc should be analyzed by the direct aspiration procedure
           whenever possible
      5.    For every sample matrix analyzed, verification is necessary to determine that method of
           standard addition is not required  (see part  5 2 1 of the Atomic Absorption Methods
           section of this manual)
      6    If method of standard addition is required, follow the procedure given earlier in part 8 5
           of the Atomic Absorption Methods section of this manual
      7    Data to be entered into STORET must be reported as ug/1

Precision and Accuracy
      1     Precision and accuracy data are not available at this time
                                         289 2-2

-------
                                      ACIDITY

                             Method 305.1 (Titrimetric)

                                                                STORET  NO. 70508

     Scope and Application
     1 1  This method is applicable to surface waters, sewages and industrial wastes, particularly
          mine drainage and receiving streams, and other waters containing ferrous iron or other
          polyvalent cations in a reduced state
     1 2  The method covers the range from approximately 10 mg/1 acidity to approximately
          1000 mg/1 as CaCO3, using a 50 ml sample
     Summary of Method
     2 1  The pH of the sample is determined and a measured amount of standard acid is added, as
          needed, to lower the pH to 4 or less Hydrogen peroxide is added, the solution boiled for
          several minutes, cooled, and titrated electrometncally with standard alkali to pH 8 2
     Definitions
     3 1  This method measures the mineral acidity of a sample plus the acidity resulting from
          oxidation and hydrolysis of polyvalent cations, including salts of iron and aluminum
     Interferences
     4 1  Suspended matter present in the sample,  or precipitates formed during the titration may
          cause a sluggish electrode response This  may be offset by allowing a 15-20 second pause
          between additions of titrant or by slow drop wise addition of titrant as the endpomt pH is
          approached
     Apparatus
     5 1  pH meter, suitable for electrometric titrations
     Reagents
     6 1  Hydrogen peroxide (H2O2, 30% solution)
     6 2  Standard sodium hydroxide, 0 02 N
     6 3  Standard sulfunc acid, 0 02 N
     Procedure
     7 1  Pipet 50 ml of the sample into a 250 ml beaker
     7 2  Measure the pH of the sample If the pH is above 4 0, add standard sulfunc acid (6 3) in
          5 0 ml increments to lower the pH to 4 0 or less If the initial pH of the sample is less than
          4 0, the incremental addition of sulfunc acid is not required
     7 3  Add 5 drops of hydrogen peroxide (61)
     7 4  Heat the sample to boiling and continue boiling for 2 to 4 minutes In some instances, the
          concentration of ferrous iron in a sample is such that an additional amount of hydrogen
          peroxide and a slightly longer boiling time may be required
Approved for  NPDES
Issued 1971
Technical revision 1974

                                         305 1-1

-------
      7 5   Cool the sample to room temperature and titrate electrometncally with standard sodium
            hydroxide (6 2) to pH 8 2
 8,    Calculations
      81   Acidity, as mg/1 CaCO, =   [(A x B) -  (C x D)] x 50,000
                                              ml of sample
           where
           A = vol  of standard sodium hydroxide used in titration
           B == normality of standard sodium hydroxide
           C = volume of standard sulfunc acid used to reduce pH to 4 or less
           D = normality of standard sulfunc acid
      82  If it is desired to report acidity in millequivalents per liter, the reported values as CaCO3
           are divided by 50, as follows
                          Acidity as  meq/1 =  mg/1 CaCO3
9,    Precision
      91   On a round robin conducted by ASTM on 4 acid mine waters, including concentrations
           up to 2000 mg/1, the precision was found to be   10 mg/1

                                       Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", p 116, D  1067, Method E(1976)
2    Standard Methods for the  Examination of Water  and Wastewater, 14th Edition, p 277
     Method 402(4d) (1975)
                                        305 1-2

-------
                                  United States
                                  Environmental Protection
                                  Agency
                                  Environmental Monitoring and
                                  Support Laboratory
                                  Cincinnati OH 45268
                                  Research and Development
vvEPA
Test  Method
                                  Acidity  (Titrimetric)-
                                  Method  305.2
                                  1   Scope and Application

                                  1 1 This method is applicable to
                                  ram, surface and other waters of pH
                                  less than 8 3

                                  1 2 This method is a measure of the
                                  concentration of strong and weak
                                  acids that react with hydroxyl ions
                                  This includes the dissolved gases that
                                  are present

                                  1 3 The range of this method
                                  depends on the volume of sample
                                  titrated and upon the precision that
                                  the increments of titrant can be
                                  measured If only 10 mL of sample is
                                  available for analysis  it is necessary
                                  to use a 50 fiL syringe for dispensing
                                  the titrant in order to achieve a
                                  precision of less than  10 /ueq/L

                                  2  Summary of Method

                                  2 1  Samples are titrated with 0 02 N
                                  carbonate free NaOH solution The
                                  end point is determined with a pH
                                  meter Results are reported as
                                  microequivalents (/ueq) per liter

                                  3  Sampling Handling and
                                  Storage

                                  3 1  The sample container must be
                                  filled completely, sealed and stored at
                                  4C Care must be taken to minimize
                                  exposure of the sample to the
                                  atmosphere Open the sample
                                  container immediately before analysis

                                  3 2  Analysis should be performed as
                                  soon as possible after collection

                                  4  Comments

                                  4 1  Samples with an initial pH
                                  between 4 3 and 8  3 are subject to
                                  error due to the loss or gam of
                                  dissolved gases during sampling
                                  storage and analyses

                                  5   Apparatus

                                  51  pH meter and electrode(s), see
                                  Method 150 1 or 150 2

                                  5 2  Micro buret or micro syrings

                                  5 3  Teflon or glass magnetic stirring
                                  bar

                                  5 4  Magnetic stirrer

                                  5 5  Beakers or flasks

                                   6   Reagents

                                   6 1  Standard sodium hydroxide
                                   solution, 1 N  Dissolve 40g NaOH in
                                   250 mL distilled water Cool and dilute
                                   to 1  liter with C02 free distilled water
                                   Store in a polyolefin bottle and fitted
                                   with a soda lime tube or tight cap to
                                   protect from atmospheric C02

                                   6 2  Standard sodium hydroxide
                                   titrant, 0 02 N Dilute 20 0 mL of 1 N
                                   NaOH with CO2-free distilled water to
                                   1 liter  Store in rubber stoppered
                                   bottle  Protect from atmospheric COa
                                   by using a soda  lime tube
                                   Standardize against an 0 02 N
                                   potassium acid phthalate solution
                                   prepared by dissolving 4 085  g of
                                   anhydrous KHCaH4O4 in COa free
                                   distilled water and diluted to  1 1

                                   7  Procedure

                                   7 1   Pipet an appropriate aliquot of
                                   sample into beaker of flask containing
                                   a small teflon on glass stirring bar
                                   Use extreme care to minimize the
                                   sample surface disturbance
                                   3052 1
                                                           Dec 1982

-------
7.2 Immerse pH electrode(s) into
sample and stir at a rate that does not
cause sample surface disturbance

7.3 Titrate with 0 02 N NaOH (6 2)
to pH 8 3 Titration should be made as
quickly as possible to prevent
absorption of atmospheric CO2
Record volume of titrant

8.  Calculation
8 1  Acidity. //eq/L =TIx NB x 1 05
                  mLs

            fjeq/L = microequivalents
                   per liter

            mLa = mL of NaOH titrant

              mLs = mL of sample

            NB = normality of titrant

9.   Precision and Accuracy

9 1  Precision and accuracy data are
not available

References
1 ,   Seymour, M D . Schubert, S A ,
    Clayton, J W and Fernando, Q ,
    Variation in the Acid Content of
    Rain Water in the Course of a
    Single Precipitation, Water, Air
    and Soil Pollution 10{2) 147-161,
    Aug 1978
2   Peden, M E and Skowron, Ionic
    Stability of Precipitation Samples,
    Atmospheric Environment, Vol
    12, pp 2343-2349 1978
3   USGS, Methods for Collection and
    Analysis of Water Samples for
    Dissolved Minerals and Gases, p
    39, (1970)
4   Annual Book of ASTM Standards,
    part 31, "Water, ' p  107, D1067,
    (1978)
5   Standard Methods for the
    Examination of Water and
    Wastewater, 14th Edition, p 273,
    Met hod 402 (1975)
                                   Dec 1982                    3052-2

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                                    ALKALINITY

                        Method  310.1  (Titrimetric, pH  4.5)

                                                                STORET NO.  00410

     Scope and Application
     1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
          wastes
     1 2   The method is suitable for all concentration ranges of alkalinity, however, appropriate
          aliquots should be used to avoid a titration volume greater than 50 ml
     1 3   Automated titnmetric analysis is equivalent
     Summary of Method
     2 1   An unaltered sample is titrated to an electrometncally determined end point of pH 4 5
          The sample must not be filtered, diluted, concentrated, or altered in any way
     Comments
     3 1   The sample should be refrigerated at 4C and run as soon as practical  Do not open
          sample bottle before analysis
     3 2   Substances, such as salts of weak organic and inorganic acids present in large amounts,
          may cause interference in the electrometnc pH measurements
     3 3   For samples  having high  concentrations of mineral acids, such as mine wastes and
          associated receiving waters, titrate to an electrometnc endpomt of pH 3 9, using the
          procedure in
          Annual Book of ASTM Standards, Part 31, "Water", p 115, D-1067, Method D, (1976)
     3 4   Oil and grease, by coating the  pH  electrode,  may also interfere, causing sluggish
          response
     Apparatus
     4 1   pH meter or electrically operated titrator that uses a glass electrode and can be read to
          0 05 pH units  Standardize and calibrate according to manufacturer's instructions  If
          automatic temperature compensation is not provided, make titration at 25 2 C
     4 2   Use an appropriate sized vessel to keep the air space above the solution at a minimum
          Use a rubber stopper fitted with holes for the glass electrode, reference electrode (or
          combination electrode) and buret
     4 3   Magnetic stirrer, pipets, flasks and other standard laboratory equipment
     4 4   Burets, Pyrex 50,25 and 10 ml
     Reagents
     5 1   Sodium carbonate solution, approximately 0 05 N  Place 25 0 2 g (to nearest mg)
          Na2CO3 (dned at 250C for 4 hours and cooled in desiccator) into a 1  liter volumetric
          flask and dilute to the mark
Approved for NPDES
Issued 1971
Editorial revision 1978

                                         310 1-1

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       5.2   Standard acid (sulfunc or hydrochloric), 0 1 N Dilute 3 0 ml cone H2SO4 or 8 3 ml cone
            HC1 to 1 liter with distilled water Standardize versus 40 0 ml of 0 05 N Na2CO3 solution
            with about 60 ml distilled water by titrating potentiometncally to pH of about 5  Lift
            electrode and rinse into beaker Boil solution gently for 3-5 minutes under a watch glass
            cover Cool to room temperature Rinse cover glass into beaker Continue titration to the
            pH inflection point Calculate normality using
            N=    A x B
                   5300 x C

                                                    '  '
                 where
                 A = g Na2CO3 weighed into 1 liter
                 B = ml Na2CO3 solution
                 C t= ml acid used to inflection point
                                  ,',-"'        '    .   '      '
      5 3  Standard acid (sulfunc or hydrochloric), 0 02 N  Dilute 200 0 ml of 0 1000 N standard
           acid to 1 liter with distilled water  Standardize by potentiometnc titration of 15 0 ml 0 05
           N Na2CO3 solution as above
 6    Procedure
      6.1  Sample size                           '                               '
           6 1  1  Use a sufficiently large volume of titrant (> 20 ml in a 50 ml buret) to obtain good
                 precision while keeping volume low enough to permit sharp end point
           6 1  2  For  < 1000 mg CaCO3/l use 0 02 N titrant
           6 1  3  For  > 1000 mg CaCO3/l use 0 1 N titrant  ,
           6 1  4  A preliminary titration is helpful
      6 2  Potentiometnc titration
           6.2  1  Place sample in flask by pipetting with pipet tip near bottom of flask
           622  Measure pH of sample
           623 Add standard acid (5 2 or 5 3), being careful to stir thoroughly but gently to allow
                needle to obtain equilibnum
           624 Titrate to pH4 5. Record volume pf titrant
      6 3   Potentiometnc titration of low alkalinity
           63  1 For  alkalinity of <20 mg/1  titrate 100-200 ml as above (62) using a  10 ml
                microburet and 0 02 N acid solution (5 3)
           632 Stop titration at pH  in range of  4 3-4 7,  record volume and  exact pH Very
             * carefully add titrant to lower pH exactly 0 3 pH units and record volume
7.    Calculations
      71   Potentiometnc titration to pH 4 5                   -  >


           Alkalinity, mg/1 CaC03=   A x  N x 50,000
                                       ml  of sample
                                         310 1-2

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          where
          A = ml standard acid
          N = normality standard acid
     7 2  Potentiometnc titration of low alkalinity
          TotaUlkahmty.mg/iCaCO, = (2B
          where
          B = ml titrant to first recorded pH
          C = total ml titrant to reach pH 0 3 units lower
          N = normality of acid
     Precision and Accuracy
     8 1   Forty analysts in seventeen laboratories analyzed synthetic water samples containing
          increments of bicarbonate, with the following results
      Increment as
       Alkalinity
    mg/liter, CaCO3
            8
            9
          113
          119
   Precision as
Standard Deviation
rag/liter, CaCO3
         Accuracy as
Bias,                  Bias,
                  mg/1,  CaCO3
127
1 14
528
536
+ 10.61
+22,29
- 8J9
- 7.42
+085
+ 20
-93
-88
(FWPCA Method Study 1, Mineral and Physical Analyses)

     82  In a single laboratory (EMSL) using surface water samples at an average concentration
          of 122 mg CaCO3/l, the standard deviation was 3

                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater,  14th  Edition,  p 278,
     Method 403, (1975)
2    Annual Book of ASTM Standards, Part 31, "Watei", p 113, D-1067, Method B, (1976)
                                        310 1-3

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                                    ALKALINITY

            Method 310.2 (Colorimetric, Automated,  Methyl Orange)

                                                                STORET NO. 00410

1    Scope and Application
     1 1  This automated method is applicable to drinking, surface, and saline waters, domestic
          and industrial wastes  The applicable range is 10 to 200 mg/1 as CaCO3
     1 2  This method is not  an approved NPDES method  as  cited in the  Federal Register
          December 1,1976 for samples containing tuibidity or color
2    Summary of Method
     2 1  Methyl orange is used as the indicator in this method because its pH range is in the same
          range as the equivalence point for total alkalinity, and it has a distinct color change that
          can be easily measured The methyl orange is dissolved in a weak buffer at a pH of 3 1,
          just below the equivalence point, so that any addition of alkalinity causes a loss of color
          directly proportional to the amount of alkalinity
3    Sample Handling and Preservation
     3 1  Sample should be refrigerated at 4C and run as soon as practical  Do not open sample
          bottle before analysis
4    Interferences
     4 1  Sample turbidity and color may interfere with this method  Turbidity must be removed
          by  filtration prior to analysis  If sample is filtered, this method is not approved for
          NPDES monitoring  Sample color that absorbs in the photometric range used will also
          interfere
5    Apparatus
     5 1  Techmcon AutoAnalyzer  consisting of
          5 1 1  Sampler I
          5 1 2  Manifold
          513  Proportioning pump
          514  Colorimeter equipped with 15 mm tubular flow cell and 550 nm filters
          515  Recorder equipped with range expander
6    Reagents
     6 1  Methyl Orange Dissolve 0 125 g of methyl orange in 1 liter of distilled water
     6 2  pH 3  1 Buffer  Dissolve 5  1047 g of potassium acid phthalate in  distilled water and add
          87  6 ml 0 1 N HC1 and dilute to 1 liter Stable for one week
     6 3  Methyl Orange-Buffered Indicator Add 1 liter of pH 3 1 buffer  (6 2) to 200 ml methyl
          orange solution (6 1) and mix well Stable for 24 hours
     6 4  Stock Solution Dissolve 1 060 g of anhydrous sodium carbonate (oven-dried at 250C for
          4 hours) in distilled water and dilute to 1000 ml 1 0 ml = 1 00 mg CaCO3

Approved for  NPDES
Issued 1971
Editorial revision 1974

                                         3102-1

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            641 Prepare a series of standards by diluting suitable volumes of stock solution to 100 0
                 ml with distilled water The following dilutions are suggested

                       ml  of Stock
                        Solution                               Cone, mg/1 as CaCO3

                        10                                            10
                        20                                            20
                        40                                            40
                        60                                            60
                        80                                            80
                        100                                           100
                        180                                           180
                        200                                           200

 7.    Procedure
      7 1   No advance sample preparation is required Set up manifold as shown in Figure 1
      7 2   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
           reagents, feeding distilled water through the sample line  Adjust dark current and
           operative opening on colorimeter to obtain stable baseline
      7 3   Place distilled water wash tubes in alternate openings on sampler and set sample timing
           at 2 0 minutes
      7 4   Place working standards  in sampler in order of decreasing concentration Complete
           filling of sampler tray with unknown samples
      7 5   Switch sample line from distilled water to sampler and begin analysis
 8.    Calculation
      8.1   Prepare standard curve by plotting peak heights of processed standards against known
           concentrations Compute concentration of samples by comparing sample peak heights
           with standard curve
 9     Precision and Accuracy
      91   In a single laboratory (EMSL), using surface water samples at concentrations of 15, 57,
           154, and 193 mg/1 as CaCO3 the standard deviation was 0 5
      9.2   In a single laboratory (EMSL), using surface water samples at concentrations of 31 and
           149 mg/1 as CaCO3 recoveries were 100% and 99%, respectively

                                      Bibliography

 1     Techmcon Auto Analyzer Methodology, Bulletin 1261, Techmcon Controls, Inc, Chauncey,
      NY (1961)
2.     Standard Methods  for the Examination  of Water and Wastewater, 14th Edition, p  278,
      Method 403 (1975)
                                         3102-2

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310 2-3

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                                      BROMIDE

                              Method 320.1 (Titrimetric)

                                                                 STORET  NO.  71870

      Scope and Application
      1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
           waste effluents
      1 2   The concentration range for this method is 2-20 mg bromide/1
      Summary of Method
      2 1   After pretreatment to remove interferences, the sample is divided into two ahquots One
           aliquot is analyzed for iodide by converting the iodide to lodate with bromine water and
           titrating lodometncally with phenylarsine oxide (PAO) or sodium thiosulfate The other
           aliquot is analyzed for iodide plus bromide by converting these hahdes to lodate and
           bromate with calcium hypochlonte and titrating lodometncally  with PAO or sodium
           thiosulfate Bromide is then calculated by difference
      Sample Handling and Preservation
      3 1   Store at 4C and analyze as soon as possible
      Interferences
      4 1   Iron, manganese  and organic  matter  can  interfere,  however, the calcium oxide
           pretreatment removes or reduces these to insignificant concentrations
      4 2   Color interferes with the observation of indicator and bromine-water color changes This
           interference is eliminated by the use of a pH meter instead of a pH indicator and the use
           of standardized amounts of oxidant and oxidant-quencher
      Reagents
      5 1   Acetic Acid Solution (1 8) Mix 100 ml of glacial acetic acid with 800 ml of distilled
           water
      5 2   Bromine Water In a fume hood, add 0 2 ml bromine to 500 ml distilled water Stir with a
           magnetic sttrrer and a Teflon-coated stirring bar for several hours or until the bromine
           dissolves Store in a glass-stoppered, colored bottle
      5 3   Calcium Carbonate (CaCO3) Powdered
      5 4   Calcium Hypochlonte Solution (Ca(OCl)2), Add 35 g of Ca(OCl)2 to approximately 800
           ml of distilled water m a 1  liter  volumetric flask Stir  on a magnetic stirrer for
           approximately 30 minutes  Dilute to 1 liter and filter  Store in a glass-stoppered, colored
           flask
      5 5   Calcium Oxide (CaO) Anhydrous, powdered
      5 6   Hydrochloric  Acid Solution (1 4)  Mix  100 ml of HC1 (sp  gr  1 19) with 400 ml of
           distilled water
Approved for NPDES
Issued 1974

                                         320 1-1

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 5 7   Potassium Iodide (KI) Crystals, ACS Reagent Grade
 5 8   Sodium Acetate  Solution  (275  g/1)  Dissolve 275  g  sodium  acetate tnhydrate
      (NaC2H3O23H2O) in distilled water Dilute to 1 liter and filter
 5 9   Sodium Chloride (NaCl) Crystals, ACS Reagent Grade
 5.10  Sodium Formate Solution (500 g/1) Dissolve 50 g sodium formate (NaCHO2) in hot
      distilled water and dilute to 100 ml
 5 11  Sodium Molybdate Solution (10 g/1) Dissolve 1 g sodium molybdate (Na2MoO42H2O)
      in distilled water and dilute to 100 ml
 5 12  Sulfunc Acid Solution (1 4)  Slowly add 200 ml H2SO4 (sp gr 1 84) to 800 ml of distilled
      water
 513  Phenylarsme Oxide  (0 0375N) Hach Chemical Co, or equivalent  Standardize  with
      0 0375 N potassium buodate (5 19, 5 23)
 5 14  Phenylarsme Oxide Working Standard (0 0075 N) Transfer 100 ml  of commercially
      available 0 0375 N phenylarsme oxide (5 13) to a 500 ml volumetric flask and dilute to
      the mark with distilled water This solution should be prepared fresh daily
 5 15  Commercially available starch indicator such as thyodene or equivalent may be used
 5 16  Sodium Thiosulfate, Stock Solution, (0 75 N)  Dissolve 186 14 g Na2S2O35H2O in boiled
      and cooled distilled water and dilute to 1 liter  Preserve by adding 5 ml chloroform
 5 17  Sodium Thiosulfate Standard Titrant, (0 0375 N)  Prepare by diluting 50 0 ml of stock
      solution (5 16) to  10 liter  Preserve by adding 5 ml  of chloroform Standardize  with
      0 0375 N potassium buodate (5 19, 5 23)
 5.18  Sodium Thiosulfate Working  Standard  (00075 N)  Transfer 100  ml of sodium
      thiosulfate standard titrant (5 17) to a 500 ml volumetric flask and dilute to the mark
      with distilled water This solution should be prepared fresh daily
 5 19  Potassium Bnodate  Standard, (0 0375 N)  Dissolve  4 873 g potassium  buodate,
      previously dried 2 hours at 103C, in distilled water and dilute to 1 0 liter Dilute 250 ml
      to 1 0 liter for 0 0375 N buodate solution
 5 20  Starch Solution  Prepare an emulsion of 10 g of soluble starch in a mortar or beaker  with
      a small quantity of distilled water  Pour this emulsion into 1 liter of boiling water, allow
      to boil a few minutes, and let settle overnight  Use the clear supernate This solution  may
      be preserved by the addition of 5 ml per liter of chloroform and storage in a  10C
      refrigerator Commercially available dry, powdered starch indicators may be used in
      place of starch solution
521   Nitrogen Gas Cylinder
5 22   Potassium Fluoride (KF2H2O) ACS Reagent Grade
5 23   Standardization of 0 0375 N Phenylarsme Oxide and 0 0375 N Sodium Thiosulfate
      Dissolve approximately 2 g (  1 0 g) KI (5 7) in 100 to 150 ml distilled water, add 10 ml
      H2SO4 solution (5  12) followed by 20 ml standard potassium buodate solution (5  19)
      Place in dark for 5 minutes, dilute to 300 ml and titrate with the phenylarsme oxide
      (5 13) or sodium thiosulfate (5 17) to a pale straw color Add a small scoop of indicator
      (5 15)  Wait until homogeneous blue color develops and continue the titration drop by
      drop until the color disappears Run in duplicate  Duplicate determinations should agree
      within 005 ml
                                    320 1-2

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Procedure
6 1   Pretreatment
     611  Add a visible excess of CaO (5 5) to 400 ml of sample  Stir or shake vigorously for
           approximately 5 minutes Filter through a dry, moderately retentive filter paper,
           discarding the first 75 ml
6 2   Iodine Determination
     621  Place 100 ml of pretreated sample (6 1) or a fraction thereof diluted to that volume,
           into a 150 ml beaker Add a Teflon-coated stirring bar and place on a magnetic
           stirrer Insert a pH electrode and adjust the pH to approximately 7 or slightly less
           by the dropwise addition of H2SO4 solution (5 12)
     622  Transfer the sample to  a 250 ml widemouthed conical flask Wash beaker with
           small amounts of distilled water and add washings to the flask A 250 ml iodine
           flask would increase accuracy and precision by preventing possible loss of the
           iodine generated upon addition of potassium iodide and sulfunc acid (641)
     623  Add 15 ml sodium acetate solution (5 8) and 5 ml acetic acid solution (5  1) Mix
           well Add 40 ml bromine water solution (5 2), mix well Wait 5 minutes
     624  Add 2 ml sodium formate solution (5 10), mix well Wait 5 minutes
     625  Purge space above sample with gentle stream of nitrogen (521) for approximately
           30 seconds to remove bromine fumes
     626  If a precipitate forms (iron), add 0 5 g KF2H2O (5 22)
     6 2 7  A distilled water blank must be run with each set of samples because of iodide in
           reagents If the blank is consistently shown to be zero for a particular "lot" of
           chemicals, it can be ignored
     628  Titrate as described in 6 4
6 3   Bromide Plus Iodide Determination
     631  Place 100 ml of pretreated sample (6 1) or a fraction thereof diluted to that volume,
           in a 150 ml beaker  Add 5 g NaCl and stir to dissolve  Neutralize by dropwise
           addition of HC1 solution (5 6) as in (6 2 1)  Transfer as in (6 2 2)
     632  Add 20 ml of calcium hypochlonte solution (5 4)  Add 1 ml of HC1 solution (5 6)
           and add approximately 0 2 g calcium carbonate (5 3)
     633  Heat to boiling on a hot plate, maintain boiling for 8 minutes
     634  Remove from hot plate and carefully add 4 ml sodium formate solution (5 10)
           Caution  TOO RAPID  ADDITION MAY CAUSE FOAMING   Wash down
           sides with distilled water
     635  Return to hot plate and maintain boiling conditions for an additional  8 minutes
           Occasionally wash down sides with distilled water if residue is deposited  from
           boiling action
     636  Remove from hot plate Wash down sides and allow to cool
     6 3 7  If a precipitate forms (iron), add 0 5 g KF2H2O (5 22)
     638  Add 3 drops sodium molybdate solution (5 11)
     6 3 9  A distilled water blank  must be  run with each set of samples because of iodide,
           lodate, bromide, and/or bromate in reagents
     6310 Titrate as described in 6 4
                                    320 1-3

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      6 4  Titration
           6 4 1 Dissolve approximately 1 g potassium iodide (5 7) in sample from (6 2 8 or 6 3 10)
                Add 10 ml of fr2SO4 solution (5 12) and place in dark for 5 minutes
           642 Titrate with standardized phenylarsine pxide working standard (5 14) or sodium
                thiosulfate working standard (5 18), adding indicator (5 15 or 5 20) a&end point is
                approached (light straw color) Titrate to colorless solution Disregard returning
                blue color
7     Calculations
      7 1   Principle Iodide is determined by the titration of the sample as  oxidized in (6 2)
           bromide plus iodide is determined by the titration of the sample as oxidized in (6 3) The
           amount of bromide is then determined by difference The number of equivalents of iodine
           produced a constant of 13,320 as shown in the equation in (7 2) Experimental data is
           entered in the appropriate place and the equation is solved for mg/1 bromide
      7 2   Equation
           Br(mg/l) = 13,320
                where
                A = the number of ml of PAO needed to titrate the sample for bromide plus iodide
                     (with the number of ml of PAO needed to titrate the blank subtracted)
                B = the normality of the PAO needed to titrate the sample for bromide plus
                     iodide
                C = the volume of sample taken (100 ml or a fraction thereof) to be titrated for
                     bromide plus iodide
                D = the number of ml of PAO needed to titrate the sample for iodide (with the
                     number of ml of PAO needed to titrate the blank subtracted) The blank for
                     the iodide titration is often zero
                E = the normality of the PAO used to titrate the sample for iodide
                F = the volume of sample taken (100 ml or a fraction thereof) to be titrated for
                     iodide
8.    Precision and Accuracy
     81   In a single laboratory (EMSL), using a mixed domestic and industrial waste effluent, at
           concentrations of 0 3, 2 8, 5 3, 10 3 and 20 3 mg/1 of bromide, the standard deviations
           were 013,  037, 038, 044 and  042mg/l,"respectively
     82   In a single laboratory (EMSL), using a mixed domestic and industrial waste effluent, at
           concentrations of 2 8, 5 3, 10 3  and 20 3 mg/1 of bromide, recoveries were 96, 83, 97 and
           99%, respectively
                                         320 1-4

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                                      Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D1246-68, Method C, p 328
     (1976)
2    Bender, D F ,  "Modification of the lodimetnc Titration Methods for the Determination of
     Bromide  and  its  application to  Mixed  Domestic-Industrial Waste Effluents", Analyst
     (London), 100.  p 400-404 (June 1975)
                                       320 1-5

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                                      CHLORIDE

            Method  325.1  (Colorimetric,  Automated  Ferricyanide  AAI)

                                                                 STORET NO.  00940

      Scope and Application
      1 1   This automated method is applicable to drinking, surface, and saline waters, domestic
           and industrial wastes The applicable range is  1 to 250 mg Cl/1  Approximately 15
           samples per hour can be analyzed
      Summary of Method
      2 1   Thiocyanate ion (SCN) is liberated from mercuric thiocyanate'through sequestration of
           mercury by chloride ion to form un-iomzed mercuric chloride  In the presence of ferric
           ion,  the  liberated  SCN forms highly  colored ferric  thiocyanate in concentration
           proportional to the original chloride concentration
      Sample Handling and Preservation
      3 1   No special requirements
      Interferences
      4 1   No significant interferences
      Apparatus
      5 1   Techmcon Auto Analyzer consisting of
           5 1 1 Sampler I
           512 Continuous filter
           5 1 3 Manifold
           514 Proportioning pump
           5 1 5 Colorimeter equipped with 15 mm tubular flow cell and 480 nm filters
           516 Recorder
      Reagents
      6 1   Ferric Ammonium Sulfate  Dissolve 60 g of FeNH4(SO4)212H2O in approximately 500
           ml distilled  water Add 355 ml of cone  HNO3 and dilute to 1 liter with distilled water
           Filter
      6 2   Saturated Mercunc Thiocyanate Dissolve 5 g of Hg(SCN)2 in  1 liter of distilled water
           Decant and filter a portion of the saturated supernatant liquid to use as the reagent and
           refill the bottle with distilled water
      6 3   Stock Solution (0 0141 N NaCl) Dissolve 0 8241 g of pre-dried (140C) NaCl in distilled
           water Dilute to 1 liter in a volumetric flask 1 nil = 0 5 mg Cl
           631 Prepare a series of standards by diluting suitable volumes of stock solution to 100 0
                ml with distilled water The following dilutions are suggested
Approved for NPDES
Issued 1971
                                         325 1-1

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                      ml of Stock
                        Solution                                    Cone, mg/1

                        10                                           50
                        20                                          100
                        40                                          200
                        80                                          400
                       15 0                                          75 0
                       20 0                                         100 0
                       30 0                                         150 0
                       40 0                                         200 0
                       50 0                                         250 0
7    Procedure
     7.1   No advance sample preparation is required  Set up manifold as shown in Figure 1  For
           water samples known to be consistently low in chloride content, it is advisable to use only
           one distilled water intake line
     7 2   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
           reagents,  feeding distilled water through the sample line  Adjust dark current  and
           operative opening on colorimeter to obtain stable baseline
     7 3   Place distilled water wash tubes in alternate openings in sampler and set sample timing at
           2 0 minutes
     7 4   Place working standards in sampler in order of decreasing concentrations Complete
           filling of sampler tray with unknown samples
     7 5   Switch sample line from distilled water to sampler and begin analysis
8    Calculation
     8 1   Prepare standard curve by plotting peak heights of processed standards against known
           concentrations Compute concentration of samples by comparing sample peak heights
           with standard curve
9    Precision and Accuracy
     91   In a single laboratory (EMSL), using surface water samples at concentrations of 1,  100,
           and 250 mg Cl/1, the standard deviation was 0 3
     92   In a single laboratory (EMSL), using surface water samples at concentrations of 10 and
           100 mg Cl/1, recoveries were 97% and 104%, respectively

                                       Bibliography

1    J E O'Brien, "Automatic Analysis of Chlorides m Sewage", Waste Engr , 33, 670-672 (Dec
     1962)
2    Standard  Methods  for the Examination of Water and Wastewater,  14th Edition, p 613,
     Method 602 (1975)
                                         325 1-2

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325 1-3

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                                      CHLORIDE

            Method 325.2 (Colorimetric, Automated Ferricyanide AAII)

                                                                 STORET  NO.  00940

      Scope and Application
      1 1   This automated method is applicable to drinking, surface, and saline waters, domestic
           and mdustral wastes The applicable range is 1  to 200 mg Cl/1  This range may be
           extended by sample dilution Approximately 30 samples per hour can be analyzed
      Summary of Method
      2 1   Thiocyanate ion (SCN) is liberated from mercuric thiocyanate through sequestration of
           mercury by chloride ion to form un-ionized mercuric chloride In the presence of feme
           ion, the liberated SCN  forms highly colored  feme  thiocyanate in concentration
           proportional to the original chloride concentration
      Sample Handling and Preservation
      3 1   No special requirements
      Interferences
      4 1   No significant interferences
      Apparatus
      5 1   Techmcon AutoAnalyzer consisting of
           511 Sampler
           512 Continuous filter (optional)
           513 Analytical cartridge
           514 Proportioning pump
           5 1  5 Colorimeter equipped with 15 mm tubular flow cell and 480 nm filters
           516 Recorder
           5 1 7 Digital printer (optional)
      Reagents
      6 1   Mercuric thiocyanate solution Dissolve 4 17 gm of Hg(SCN)2 in 500 ml of methanol
           Dilute to 1 liter with methanol, mix and filter through filter paper
      6 2   Ferric nitrate solution, 20 2% Dissolve 202 gm of Fe(NO3)39 H2O in 500 ml of distilled
           water Add 31 5 ml cone nitric acid, mix and dilute to 1 liter with distilled water
      6 3   Color reagent Add 150 ml of mercuric thiocyanate solution (6 1) to 150 ml of feme
           nitrate solution (6 2), mix, and dilute to 1 liter with distilled water
      6 4   Stock Solution (0 0141 N NaCl) Dissolve 0 8241 g of pre-dried (140C) NaCl in distilled
           water Dilute to 1 liter in a volumetric flask 1 ml = 0 5 mg Cl
           641 Prepare a series of standards by diluting suitable volumes of stock solution to 100 0
                ml with distilled water The following dilutions are suggested
Approved for NPDES
Issued 1978

                                         325 2-1

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                      ml of Stock                                  Cone, mg/1
                       Solution

                        10                                           50
                        20                                           100
                        40                                           200
                        80                                           400
                       150                                           750
                       20 0                                          100 0
                       300                                          1500
                       400                                          2000
7    Procedure
     7 1  Where  participate  matter is  present, the  sample must be filtered prior to the
          determination This can be accomplished by having the Techmcon continuous filter as an
          integral part of the system The sample may be centnfuged in place of filtration
     7 2  Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
          reagents, feeding distilled water through the sample line
     7.3  Place working standards in sampler in order of decreasing concentrations  Complete
          filling of sampler tray with unknown samples
     7,4  When a stable baseline has been obtained, start the sampler
8    Calculation
     8 1  Prepare standard curve by plotting peak heights of processed standards against known
          concentrations Compute concentration of samples by comparing sample peak heights
          with standard curve
9.    Precision and Accuracy
     9 1  Precision and accuracy data are not available at this time

                                      Bibliography

1.    J E, O'Brien, "Automatic Analysis of Chlorides in Sewage", Waste Engr, 33, 670-672 (Dec
     1962)
2.    Techmcon AutoAnalyzer II, Industrial Method No 99-70W, Techmcon Industrial Systems,
     Tarrytown, N Y, 10591 (Sept 1973)
                                         325 2-2

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           CC
           LU
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                                    325 2-3

-------
                                      CHLORIDE

                   Method 325.3 (Titrimetric, Mercuric  Nitrate)

                                                                 STORET  NO.  00940

 1     Scope and Application
      1 1   This method is applicable to drinking, surface, and saline waters, domestic and industrial
           wastes
      1 2   The method is suitable for all concentration ranges of chloride content, however, m order
           to avoid large titration volume, a sample aliquot containing not more than 10 to 20 mg Cl
           per 50 ml is used
      1 3   Automated titration may be used
2     Summary of Method
      2 1   An acidified  sample is titrated with mercuric  nitrate m the presence of  mixed
           diphenylcarbazone-bromophenol blue indicator  The end point of the titration is the
           formation of the blue-violet mercury diphenylcarbazone complex
3     Comments
      3 1   Amons and cations at concentrations normally found m surface waters  do not interfere
      3 2   Sulfite interference can be eliminated by oxidizing the 50 ml of sample solution with 0 5
           tolmlofH2O2
4     Apparatus
      4 1   Standard laboratory titnmetnc equipment including a 1 ml or 5 ml microburet with 001
           ml graduations
5     Reagents
      5 1   Standard sodium chloride, 0 025 N Dissolve! 4613 g0 0002 g sodium chloride (dried
           at 600 C for 1 hour) in chloride-free water m a 1 liter volumetric flask and dilute to the
           mark 1 ml = 886 5 fjg Cl
      5 2   Nitric acid, HNO3 solution (3 + 997)
      5 3   Sodium hydroxide solution, NaOH, (10 g/1)
      5 4   Hydrogen peroxide (30%), H2O2
      5 5   Hydroqumone solution (10 g/hter) Dissolve  1 g of purified hydroqumone m water m a
           100 ml volumetric and dilute to the mark
      5 6   Mercuric nitrate titrant (0 141 N) Dissolve 25 g  Hg(NO3)2H2O m 900 ml of distilled
           water acidified with 5 0 ml cone HNO3 m a 1 liter volumetric flask and dilute to the
           mark with distilled water  Filter if necessary Standardize against standard sodium
           chloride solution (5 1) using procedure 6 Adjust to exactly 0 141 N and check Store in a
           dark bottle A 1 00 ml aliquot is equivalent to 5 00 mg of chloride
      5 7   Mercuric nitrate titrant (0 025 N) Dissolve 4 2830 g Hg(NO3)2H2O m 50 ml of distilled
           water acidified with 0 5 ml cone HNO3 (sp  gr 1 42) m a 1 liter volumetric flask and
           dilute to the mark with distilled water  Filter if necessary Standardize against standard

Approved for NPDES
Issued 1971
Editorial revision 1978 and 1982

                                         325 3-1

-------
           sodmm chloride solution (5 1) using procedure 6 Adjust to exactly 0 025 N and check
           Store m a dark bottle
     5 8   Mercuric nitrate titrant (0 0141 N) Dissolve 2 4200 g Hg(NO3)2H2O m  25 ml of
           distilled water acidified with 0 25 ml of cone HNO3 (sp  gr  1 42) m a 1 liter volumetric
           flask and dilute to the mark with distilled water Filter if necessary Standardize against
           standard sodium chloride solution (5 1) using procedure 6  Adjust to exactly 0 0141 N
           and check Store m a dark bottle A 1 ml aliquot is equivalent to 500 ug of chloride
     5 9   Mixed  indicator reagent Dissolve 0 5  g crystalline diphenylcarbazone  and 0 05  g
           bromophenol blue powder m 75 ml 95%  ethanol in a 100 m' volumetric flask and dilute
           to the mark with 95% ethanol Store m brown bottle and discard after 6 months
     5 10  XylenecyanoleFF solution  Dissolve 0 005 g of xylene cyanole FF dye in 95% ethanol or
           isopropanol in a 100 ml volumetric and dilute to the mark with 95% ethanol or
           isopropanol
6.    Procedure
      6.1   Use 50 ml of sample or an aliquot of sample diluted to 50 ml with distilled water, so that
           the concentration of chloride does not exceed 20 mg/ahquot If the sample or aliquot
           contains more than 2 5  mg of chloride, use 0 025N mercuric nitrate titrant (5 7) in step
           6.6 If the sample or aliquot contains less than 2 5 mg of chloride, use 0 0141N mercuric
           nitrate titrant (5 8) in step 6 6  Determine an indicator blank on 50 ml chloride-free
           water using step 6 6 If the sample contains less than 0 1 mg/1 of chloride concentrate an
           appropriate volume to  50 ml
      6 2   Add 5 drops of mixed indicator reagent (5 9), shake or swirl solution
     6.3   If a blue-violet or red color appears add HNO3 solution (5 2) dropwise  until the color
           changes to yellow
     64   If a yellow  or orange color forms immediately on addition of the mixed indicator, add
           NaOH solution (5,3) dropwise until the color changes to blue-violet, then add HNO3
           solution (5 2) dropwise until the color changes to yellow
     6 5   Add 1 ml excess HNO3 solution (5 2)
     6 6   Titrate with 0 025 N mercuric nitrate titrant (5 7) until a blue-violet color persists
           throughout the solution  See 6 1  for choice  of titrant normality  (Xyjene cyanollFF
           solution (5  10) may be added with the indicator to sharpen the end point This will
           change color shades Practice runs should be made
     6.7   Additional steps to eliminate particular interferences
           6 7 1 If chromate is present and iron is not present the end point may be difficult to
                detect
                be an olive-purple color
           6 7 2 If chromate is present at > 100 mg/1 and iron is not present,  add 2 ml of fresh
                hydroqumone solution (5 5)
           673 If ferric ion is present use volume containing no more than 2 5 mg  of ferric ion or
                ferric ion plus chromate ion Add 2 ml fresh hydroqumone solution (5 5)
           674 If sulfite ion is present, add 0 5 ml of H2O2 solution (5 4) to 50 ml sample and mix
                for 1 minute
                                         325 3-2

-------
       Calculation
                     =  (A
             where
             A = ml titrant for sample
             B  = ml titrant for blank
             N = normality mercuric nitrate titrant

       mg NaCl/1 = mg chloride/1 x  1 65

       Precision and Accuracy
       8 1   Forty two analysts in eighteen laboratories analyzed synthetic water samples containing
            exact increments of chloride, with the following results
      Increment as
        Chloride
        mg/hter
   Precision as
Standard Deviation
     mg/hter
 Bias,
  %
          Accuracy as
 Bias,
mg/hter
            17
            18
            91
            97
           382
           398
       154
       132
       292
       316
      1170
      1180
+ 2 16
+ 350
+011
 -051
 -061
 -1 19
 +04
 +06
 +01
  -05
  -23
  -47
(FWPCA Method Study 1, Mineral and Physical Analyses)

     8,2   In a single laboratory (EMSL), using surface water samples at an average concentration
           of 34 mg Cl/1, the standard deviation was  10
     83   A synthetic unknown sample containing 241 mg/1 chloride, 108 mg/1 Ca, 82 mg/1 Mg,
           3  1 mg/1 K, 19 9 mg/1 Na, 1 1 mg/1 nitrate N, 0 25 mg/1 nitrite N, 259 mg/1 sulfate
           and 42 5 mg/1 total alkalinity (contributed by NaHCO3) in distilled water was analyzed
           in 10 laboratories by the mercunmetnc method, with a relative standard deviation of
           33% and a relative error of 2 9%

                                       Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D512-67, Method A, p 270
     (1976)
                                          325 3-3

-------
                        CHLORINE, TOTAL RESIDUAL

                     Method 330.1 (Titrimetric,  Amperometric)

                                                                 STORET NO. 50060

1    Scope and Application
     1 1  The amperometnc titration method is applicable to all types of waters and wastes that do
          not contain a substantial amount of organic matter
2    Summary of Method
     2 1  Chlorine  (hypochlonte ion, hypochlorous acid) and chlorammes stoichiometncally
          liberate iodine from potassium iodide at pH 4 or less
     2 2  The iodine is titrated  with standard  reducing  agent such as sodium thiosulfate or
          phenylarsine oxide using an amperometer to determine the end point
     2 3  The results are calculated as mg/1 Cl even though the actual measurement is of total
          oxidizing power because chlorine is the dominant oxidizing agent present
3    Interferences
     3 1  Manganese, nitrite and iron do not interfere
     3 2  Stirring can lower chlonne values by volatilization
     33  If dilution is necessary, it must be done with distilled water which is free of chlonne,
          chlorine-demand and ammonia
     3 4  Copper and silver poison the electrode
4    Apparatus
     4 1  An amperometer consisting of a microammeter with necessary electrical accessories,  a
          cell unit with a salt bridge, reference electrode and an agitator Commercially available
          If the entire system (including titrant delivery system) is to be used, make sure that the
          volume read off the pipet  or buret is really being delivered to the sample cell Reservoir-
          type system sometimes back up, producing false readings
     42  A microburet, 0-2 ml or 0-10 ml, depending on required precision, accuracy and range
5    Reagents
     5 1  Phenylarsine oxide solution (0 00564N), commercially available, Wallace and Tiernan or
          equivalent Standardize with potassium bnodate (5 8, 5 9)
     5 2  Potassium Iodide, KI, crystals
     5 3  Potassium Iodide Solution Dissolve 50 g KI in freshly boiled and cooled distilled water
          and dilute to 1 liter Store  in colored, glass-stoppered bottle in refrigerator Discard when
          yellow color develops
     5 4  Commercially available starch indicators such as thyodene or equivalent may be used
     5 5  Acetate  buffer  solution  (pH  4)  Dissolve 146g  anhydrous  NaC2H3O2  or 243g
          NaC2H3O23H2O in 400 ml distilled water, add 480g cone acetic acid and dilute to 1 liter
          with distilled water

Approved for NPDES
Issued  1974
Editorial revision 1978

                                          330 1-1

-------
 5 6  Sulfunc Acid (1 4) Slowly add 200 ml H2SO4 (sp gr 1 84) to 800 ml of distilled water
 5 7  Potassium buodate (0 IN) Dissolve 3 249g potassium buodate, previously dried 2 hours
      at 103C, in distilled water and dilute to 1 0 liters Store in a glass stoppered bottle
 5 8  Potassium buodate (0 005N)  Dilute 50 ml of 0 IN potassium buodate (5 7) to 1-hter in a
      volumetric flask Store in a glass stoppered bottle
 5 9  Standardization of 000564N phenylarsine oxide Dissolve approximately 2g (lg) KI
      (5 2) in 100 to 150 ml distilled water, add 10 ml H2SO4 solution (5 6) followed by 20 ml
      0 005N potassium buodate solution (5 8) Place in dark for 5 minutes, dilute to 300 ml
      and titrate with 0 00564N phenylarsine oxide solution (5 1) to a pale straw color Add a
      small scoop of indicator (5 4) Wait until homogeneous blue color develops and continue
      the titration drop by drop until the color disappears  Run  in duplicate  Duplicate
      determinations should agree within 0 05 ml


      NPAO= 20 x  5
                 ml PAO


      Adjust PAO solution if necessary and recheck
Procedure
6  1   Place 200 ml of sample in the sample container This volume is convenient because the
      buret reading m millihters is equivalent to mg/1 Cl Up to 2 mg/1 is reliably titrated this
      way Smaller sample ahquots diluted to 200 ml are used for concentrations greater than 2
      mg/1  The construction of the cell and electrode component usually require 200 ml of
      sample
6 2   Place on electrode assembly
6 3   Add 1 0 ml KI solution (5 3)
6 4   Add 1 ml acetate buffer (5 5)
6 5   Titrate with 0 00564N PAO (5 1)
66   As each increment is added the needle deflects toward rest  When the needle no longer
      deflects subtract the last drop added from the buret reading to obtain the mg/1 Cl Less
      and/or slower deflection signals that the end point is near
Calculations
7.1   For 0 00564N PAO and a 200 ml sample there are no calculations The buret reading is
      in mg/1 The  last  increment, when the needle does not deflect toward  rest, must be
      subtracted
Precision and Accuracy
8 1   More than 20 laboratories analyzed prepared samples of 0 64 and 1 "83 mg/1 total Cl
      The relative standard deviations were 24 8% and 12 5% respectively and the relative
      errors were 85% and 88% respectively
                                    330 1-2

-------
     In a single operator, single laboratory situation the following results were obtained

                                                          Rel  Stand  Dev
Sample
Matrix
Distilled Water

Drinking Water
River Water
Domestic Sewage
Average
mg/1
038
350
097
057
041
Stand Dev
mg/1
002
001
003
002
003
                                                                 61
                                                                 02
                                                                 26
                                                                 30
                                                                 69

     For these samples the results were compared to the lodometnc titration as a means of obtaining a relative
     accuracy

                      lodometnc       Amperometnc
                                                            % Recovery

                                                               1032
                                                               1018
                                                                820
                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p  322,
     Method 409C (1975)
2    Annual Book of ASTM Standards, Part 31, "Water", Standard D 1253-76, p 277, Method A
     (1976)
3    Bender, D  F , "Comparison of Methods for the Determination of Total Available Residual
     Chlorine in Various Sample Matrices", EPA Report-600/4-78-019
Sample
Matrix
Drinking Water
River Water
Domestic Sewage
lodometnc
Titration mg/1
094
056
050
Amperometnc
Titration mg/1
097
057
041
                                         330 1-3

-------
                        CHLORINE, TOTAL RESIDUAL

                   Method 330.2 (Titrimetric, Back, lodometric)
                        (Starch or  Amperometric Endpoint)

                                                                STORET NO. 50060

     Scope and Application
     1 1  The lodometric backtitration method is applicable to all types of waters but is primarily
          used for wastewater because it eliminates any contact between the full concentration of
          liberated iodine and the wastewater
     Summary of Method
     2 1  Chlorine (hypochlonte ion,  hypochlorous acid) and chlorammes  stoichiometncally
          liberate iodine from potassium iodide at pH 4 or less
     2 2  The iodine immediately quantitatively oxidizes a standardized reducing agent such as
          sodium thiosulfate or phenylarsine oxide
     2 3  The excess reducing agent is then determined by titrating with a standard iodine titrant
          The starch endpomt color change is from clear to blue
     24  A subtraction of the excess amount of reducing agent is included in the calculations and
          the results are reported as mg/1 Cl even though the actual measurement  is of total
          oxidizing power because chlorine is the dominant oxidizing agent present
     Interferences
     3 1  Manganese, iron and nitrite interference may be minimized by buffering to pH 4 before
          the addition of KI
     3 2  High concentrations of organics may cause uncertainty in the endpomt This uncertainty
          can be reduced by acidifying to pH 1 0 if manganese, iron and nitrite are absent
     3 3  Turbidity and color may make the endpomt difficult to detect Practice runs with spiked
          samples may be necessary
     Apparatus
     4 1  Standard laboratory glassware  is used  A microburet  0-2 ml or 0-10 ml is  used
          depending on the desired range and accuracy
     Reagents
     5 1  Phenylarsine oxide  solution  (0 00564N)  Wallace and  Tierman  or  equivalent
          Standardize with potassium buodate (5 6, 5 9)
     5 2  Acetate  buffer solution (pH 4)  Dissolve 146  g anhydrous NaC2H3O2  or 243 g
          NaC2H3O23H2O in 400 ml distilled water, add 480 g cone acetic acid and dilute to 1 liter
          with distilled water
     5 3  Standard iodine solution (0 IN) Dissolve 40  g KI in 25 ml distilled water, add 13 g
          resublimed iodine and stir until dissolved Transfer to a 1 liter volumetric flask and dilute
          to the mark Determine the exact normality (5 11)
Approved for  NPDES
Issued 1978

                                        330 2-1

-------
5 4   Standard iodine titrant (0 0282N) Dissolve 25 g KI m a little distilled water in a 1 liter
      volumetric flask Add the calculated amount of 0 IN standard iodine (5 3) to produce a
      0.0282N solution Standardize daily (5 12) Store m amber bottle or in dark, protect from
      sunlight at all tunes and keep from contact with rubber
5.5   Potassium biiodate (0 IN) Dissove 3 249g potassium buodate, previously dried 2 hours
      at 103"C, in distilled water and dilute to 1 0 liter Store in a glass stoppered bottle
5.6   Potassium biiodate (0 005N) Dilute 50 ml of 0 IN potassium buodate (5 5) to 1 liter in a
      volumetric flask Store m glass stoppered bottle
5 7   Commercially available starch indicators such as thyodene or equivalent may be used
5.8   Sulfunc Acid Solution (1 4) Slowly add 200 ml H2SO4 (sp gr 1 84) to 800 ml of distilled
      water
5 9   Standardization of 0 00564N phenylarsme oxide  Dissolve approximately 2g ( Ig) KI in
      100 to 150 ml distilled water, add 10 ml H2SO4 solution (5  8) followed by 20 ml 0 005N
      potassium buodate solution (5 6)  Place in dark for 5 minutes, dilute to 300 ml and titrate
      with 0 00564N phenylarsme oxide solution (5 1) to a pale straw color Add a small scoop
      of indicator (5 7)  Wait until homogenous blue color develops and continue the titration
      drop  by drop until the color disappears Run m duplicate  Duplicate determinations
      should agree within 005 ml
        NPAO  =20X0005
                    mlPAO

        Adjust PAO solution if necessary and recheck


5 10 Standardization of 0 0375N phenylarsme oxide Dissolve approximately 2 g ( Ig) KI in
     100 to 150 ml distilled water, add 10 ml H2SO4 solution (5 8) followed by 20 ml 0 IN
     potassium buodate solution (5 5) Place in dark for 5 minutes, dilute to 300 ml and titrate
     with 0 0375N phenylarsme oxide solution (5 10) to a pale straw color  Add a small scoop
     of indicator (5 7) Wait until homogenous blue color develops and continue the titration,
     drop  by drop until the color disappears Run in duplicate Duplicate determination
     should agree within  0 05 ml


        NPAO =  20X01
                    ml PAO

        Adjust PAO  solution if necessary and recheck

511 Standardization of 0 IN Iodine solution Dissolve approximately 2g ( 1 g) KI in 100 to
     150 ml distilled water, add 20 ml Iodine Solution (5 3) Dilute to 300 ml and titrate with
     0 0375N phenylarsme oxide solution (5 10) to a pale straw color  Add a small scoop of
     indicator (5 7) Wait until homogenous blue color develops and continue the titration
                                    330 2-2

-------
     drop by drop until the color disappears Run in duplicate  Duplicate determinations
     should agree within 0 05 ml
        NT      ml PAQ X 0 0375
        N'a =  	20	
        Adjust iodine solution  if necessary  and recheck

512 Standardization of 0 0282N Iodine solution Dissolve approximately 2 g ( 1 g) KI in 100
     to 150 ml distilled water, add 20 ml Iodine solution (5 4)  Dilute to 300 ml and titrate
     with 0 0375N phenylarsine oxide solution (5 10) to a pale straw color Add a small scoop
     of indicator (5 7) Wait until homogenous blue color develops and continue the titration
     drop by drop  until  the color disappears  Run in duplicate  Duplicate determinations
     should agree within  0 05 ml

     XT     ml PAO X 0 0375
     N'*=  	20	

     Adjust iodine solution if necessary and recheck

Procedure
6 1  Starch-Iodide End Point
     6 1 1  Place 5 00 ml of 0 00564N PAO solution (5 9) in a flask
     612 Add approximately Ig KI on a scoop
     6 1 3 Add 4 ml acetate buffer solution (5 2)
     614 Add 200 ml of sample For concentrations above 10 mg/1, a sample of less volume
           may be diluted to 200 ml wth chlorine-free, chlorine demand-free distilled water
     61 5 Mix well
     616 Add approximately 4 mg indicator (5 7) just before titration
     617 Titrate with 0 0282N iodine solution (5 12) to the first appearance of a blue color
           that persists after mixing Record the ml of titrant used
6 2  Amperometnc End Point
     621 Perform steps 611-615 inclusive or follow the directions of the manufacturer of
           the  amperometnc  titrator  Prepackaged  reagents  should be  checked
           (restandardized)
     622 Place the solution in the proper position on the amperometnc titrater
     623 Titrate with 0 0282N Iodine Solution (5 12) Observe the response of the meter
           needle Initially the  needle will remain stationary As the endpomt is approached
           the needle will temporarily deflect, then return to or near to its original position
           Continue dropwise  When the needle deflects and remains deflected the end point
           has been exceeded by one drop Subtract l/20th of an ml from the buret reading
           and record the result
                                     330 2-3

-------
 7.    Calculations
       mg/lCl=   (A - 5B) x 200
                      C                                                             i

            where
            A = ml000564NPAO
            B = ml00282NI2
            C = ml sample

      Precision and Accuracy
      8 1   Starch-Iodine Endpoint
            811 Precision
                 In a single operator, single laboratory situation the following results were obtained
     Sample
     Matnx

 Distilled  Water*

 Drinking Water
 River Water
 Domestic Sewageb
 Raw Sewage
   Average
    mg/1

    041
    351
    084
    084
    087
    055
  Stand  Dev
    mg/l

     005
     012
     004
     002
     007
     009
Rel Stand Dev
     122
      33
      43
      27
      76
     160
 Three replicates for distilled water Seven replicates for other sample matrices
 bSecondary treatment
                                                        1               ,   i       i  ,  -
           812 Accuracy (Relative)
                For four samples the results were compared to the lodometnc titration as a means
                of obtaining a relative accuracy
   lodometnc
     Sample
     Matnx

Drinking Water
River Water
Domestic Sewage
Raw Sewage
   Starch
  Titration
   mg/1

   085
   078
   100
Approx 0 5
    Iodide
Back Titration
    mg/1

    084
    084
    087
    055
   Recovery

     988
     1077
     870
  Approx 100 0
     8 2   Amperometnc End Point
           8 2 1 Precision
                In a single operator, single laboratory situation the following results were obtained
                                         330 2-4

-------
    Sample             Average          Stand  Dev            Rel Stand
    Matrix              mg/1             mg/l              Dev  %

Distilled  Water-         058               0 05                   88
                        3 53               0 07                   20
Drinking Water         0 82               0 05                   59
River Water             0 68             ,  0 06                   94
Domestic Sewage"        1 10               0 09                   83

"Three replicates for distilled water Seven replicates for other sample matrices
bSecondary treatment

          822 Accuracy
                For three samples the results were compared to the lodometnc titration as a means
                of obtaining a relative accuracy

                                      Amperometnc
                      lodometnc            Back
    Sample             Titration           Titration                %
    Matrix              mg/1              mg/1               Recovery

Drinking  Water           0 83               0 82                  98 8
River  Water              0 66               0 68                 103 0
Domestic Sewage         145                1 10                  75 7

                                      Bibliography


1     Standard Methods for the Examination of Water and Wastewater, 14th Ed , p 318, Method
      409B "lodometnc Method II", (1975)
2     ASTM Standards, Part 31 "Water", p 276, Method D1253-76 (1976)
3     Bender, D F, "Comparison of Methods for the Determination of Total Available Residual
      Chlorine in Various Sample Matrices", EPA Report-600/4-78-019
                                         330 2-5

-------
                        CHLORINE, TOTAL RESIDUAL

                      Method  330.3  (Titrimetrfc, lodometric)

                                                                STORET  NO.  50060

     Scope and Application
     1 1   The lodometric titration method  is applicable  to natural  and treated waters at
          concentrations greater  than 0 1 mg/1
     Summary of Method
     2 1   Chlorine (hypochlonte ion,  hypochlorous acid)  and chlorammes stoichiometncally
          liberate iodine from potassium iodide at pH 4 or less
     2 2   The iodine is titrated with a standard reducing agent such as sodium thiosulfate or
          phenylarsine oxide using a starch indicator
     2 3   The results are calculated as mg/1  Cl even though the actual measurement is of total
          oxidizing power because chlorine is the dominant oxidizing agent present
     Interferences
     3 1   Ferric, manganic and  nitnte  ions interfere, the neutral  titration minimizes these
          interferences
     3 2   Acetic acid is used for the acid titration Sulfunc acid may be used if no interferences are
          present Hydrochloric acid should never be used
     3 3   Turbidity and color may make the endpomt difficult to detect Practice runs with spiked
          samples may be necessay
     Apparatus
     4 1   Standard laboratory glassware is  used  A microburet 0-2 ml  or  0-10 ml  is used
          depending on the desired range and accuracy
     Reagents
     5 1   Acetic acid, cone (glacial)
     5 2   Potassium iodide, KI, crystals
     5 3   Phenylarsine oxide (0 00564N) Wallace and Tiernan or equivalent  Standardize with
          potassium buodate (5 8, 5 12)
     5 4   Phenylarsine oxide (0 0375N). Hach Chemical Co  or equivalent  Standardize with
          potassium buodate (5 7, 5 13)
      5 5   Commercially available starch indicators such as thyodene or equivalent may be used
     5 6   Potassium buodate (0 IN) Dissolve 3 249 g potassium buodate,  previously dried two
          hours at 103C, in distilled water and dilute to 1 0 liter Store in a glass stoppered bottle
     5 7   Potassium buodate (0 05N) Dilute 500 ml of 0 1 N potassium buodate (5 6) to 1 liter in a
          volumetric flask Store in glass stoppered bottle
     5 8   Potassium buodate (0 005N)  Dilute 50 ml of 0 1 N potassium buodate (5 6) to 1 liter in a
          volumetric flask Store in glass stoppered bottle
Approved for NPDES
Issued 1978

                                         330 3-1

-------
 5.9  Standard iodine solution (0 IN) Dissolve 40 g KI m 25 ml distilled water, add 13 g
      resubluned iodine and stir until dissolved Transfer to a 1 liter volumetric flask and dilute
      to the mark Determine the exact normality (5 14)
 5 10 Standard iodine titrant (0 0282N) Dissolve 25 g KI in a little distilled water in a 1 liter
      volumetric flask  Add  the calculated amount of 0 1  N standard iodine to produce a
      0.0282 N solution Standardize  daily (5 15)  Store in  amber bottle or in dark,  protect
      from sunlight at all times and keep from contact with rubber
 5.11  Sulfunc acid solution (1 4) Slowly add 200 ml H2SO4 (sp gr  1 84) to 800 ml of distilled
      water
 5 12  Standardization of 0 00564N phenylarsme oxide Dissolve approximately 2 g (1 g) KI
      (5 2) in 100 to 150 ml distilled water, add 10 ml H2SO4  solution (5 11) followed by 20 ml
      0 005 N potassium biiodate solution (5 8) Place in dark for 5 minutes, dilute to 300 ml
      and titrate with 0 00564N phenylarsme oxide solution (5  3) to a pale straw color Add a
      small scoop of indicator (5 5) Wait until homogeneous blue color develops and continue
      the titration drop by drop until the color disappears  Run in duplicate Duplicate
      determination should agree within 0 05 ml
      N P AO =  20 x 0 005
                  mlPAO
      Adjust PAO solution if necessary and recheck

5 13  Standardization of 00375N phenylarsme oxide Dissolve approximately 2 g (1 g) KI
      (5 2) in 100 to 150 ml distilled water, add 10 ml H2SO4 solution (5 11) followed by 20 ml
      0 05 N potassium bnodate solution (5 7) Place m dark for 5 minutes, dilute to 300 ml and
      titrate wth 0 0375 N phenylarsme oxide solution (5 4) to a pale straw color  Add a small
      scoop  of indicator (5 5)  Wait until homogeneous blue color develops and continue the
      titration drop by  drop until  the color disappears  Run in duplicate  Duplicate
      determinations should agree within 0 05 ml


      NPAO==  20X01
                ml PAO
      Adjust PAO solution if necessary and recheck
                                                              i
5 14  Standardization of 0 1 N iodine solution Dissolve approximately 2 g (1 g) KI (5 2) in
      100 to  150 ml distilled water, add 20 ml iodine solution (5 9) Dilute to 300 ml and titrate
      with 0  0375 N phenylarsme oxide solution (5 4) to a pale straw color  Add a small scoop
      of indicator (5 5) Wait until homogeneous blue color develops and continue the titration
      drop by drop until the color disappears  Run  in duplicate  Duplicate determinations
      should agree within 0 05 ml

      M    ml PAO  X 0 0375
      N'* = 	20	
                                    330 3-2

-------
     Adjust iodine solution if necessary and recheck
                                                         i
5 15 Standardization of 0 0282N iodine solution  Dissolve approximately 2 g (1 g) KI (5 2)
     in 100 to 150 ml distilled water, add 20 ml iodine solution (5 10)  Dilute to 300 ml and
     titrate with 0 0375 N phenylarsine oxide solution (5 4) to a pale straw color Add a small
     scoop of indicator (5 5) Wait until homogeneous blue color develops and continue the
     titration drop  by  drop until  the color disappears  Run in  duplicate  Duplicate
     determinations should agree within 0 05 ml

     XT    ml PAO x 0 0375
     ^'* = 	20	

     Adjust iodine solution if necessary and recheck

Procedure
6 1  This procedure gives a convenient direct reading (ml titrant = mg/1 Cl) in the range of
     the microburet (0 5 ml to 2,5 or 10 ml) The sample volume and reagent normalities may
     be varied at the analyst's discretion
6 2  Place 5 ml acetic acid in an Erlenmeyer flask containing a Teflon coated magnetic
     stirring bar
6 3  Add about 1 g KI (5 2) estimated on a spatula
6 4  Add 200 ml sample
6 5  Place on magnetic stirrer under buret
6 6  Titrate away from direct sunlight with 0 00564N PAO (5 3) to a pale straw color Add a
     scoop of indicator (5 5)  Wait until blue color is homogeneously distributed, continue
     titrating until blue color is discharged The ml of PAO is equal to the mg/1 Cl plus or
    > minus the blank correction (6 7) if any
6 7  Blank titration Using distilled water in place of the sample perform steps 6 2-6 5, add a
     scoop of indicator Perform either 6 7  1 or 6 7 2 depending on color development
     6 7 1  Blank titration A If a blue color develops titrate with 0 00564N PAO (5 3) to the
           disappearance of the blue color and record the results
     672 Blank titration B If no blue color develops titrate with 0 0282N iodine (5 10) until
           blue  color  appears Back titrate  with  0 005 64N PAO  (5 3) and record the
           difference as titration B
Calculations
7 1  The ml of PAO  titrant  is equal to  mg/1 Cl  under the volumes and 'concentrations
     described   The blank correction  A (671) can be directly  subtracted  The  blank
     correction  B (6 7 2),  which is  added,  involves a factor of 5  (unless one  substitutes
     0 00564N iodine for the 0 0282N iodine)  Normally the reagents are pure enough that the
     blank correction is insignificant and therefore unnecessary
                                     330 3-3

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8    Precision and Accuracy
     Thirty to thirty two laboratories analyzed prepared samples of 0 64, 0 84 and 1 83 mg/1 The
     relative standard deviations were 27 0%, 32 4% and 23 6% respectively and relative errors
     were 23 6%, 18 5%, and 16 7% respectively
     In a single operator, single laboratory, situation the following results were obtained

 Sample matrix          Average           Standard           Rel standard
                        mg/1            deviation             deviation
 	                             mg/l                  %

Distilled Water*          0 25               0 001                 0 23
                        4 02               0 03                  0 76
Drinking Water          0 68               0 04                  52
River water             0 30               0 03                  97
Domestic Sewage*       111               006                  59
Raw sewage            048               009                 180

Three repjicates for distilled water Seven replicates for other sample matrices
>Secondary treatment

                                      Bibliography

1.    Standard Methods for the Examination of Water and Wastewater, 14th ed p  316, Method
     409A "lodometnc Method I" (1975)
2.    ASTM Standards, Part 31, "Water", p 276, Method D1253-76 (1976)
3    Bender, D  F, "Comparison of Methods for the Determination of Total Available Residual
     Chlorine in Various Sample Matrices", EPA Report-600/4-78-019
                                         330 3-4

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                        CHLORINE,  TOTAL  RESIDUAL

                      Method  330.4 (Titrimetric,  DPD-FAS)

                                                                STORET NO.  50060

1    Scope and Application
     1 1  The N,N-diethyl-p-phenylene diamme (DPD) - ferrous  ammonium sulfate  (FAS)
           titration method is applicable to natural and treated waters at concentrations above 0 1
           mg/1 Cl
2    Summary of Method
     2 1  Chlorine (hypochlonte ion,  hypochlorous  acid) and  chlorammes stoichiometncally
          liberate iodine from potassium iodide at pH 4 or less
    ' 2 2  The iodine is titrated with FAS using DPD as the indicator
     2 3  The results are calculated as mg/1 Cl even though the actual measurement is of total
          oxidizing power because chlorine is the dominant oxidizing agent present
3    Interferences
     3 1  Bromine, bromamme and iodine are interferences which are normally present  in
          insignificant amounts
     3 2  Oxidized manganese interferes but can be corrected by subtraction after performing a
          titration in the presence of sodium arsemte (NaAsO2)
     3 3  Copper interferes but  is accounted  for  (up to  approximately  10 mg/1  copper) by
           incorporation of EDTA The EDTA also retards detenoration of DPD due to oxidation
           and completely suppresses dissolved oxygen errors by preventing trace metal catalysis
     3 4   Turbidity and color may make the endpoint difficult to detect Practice runs with spiked
           samples may be necessary
4    Apparatus
     4 1   Standard laboratory glassware is used A microburet, 0-2 ml or 0-10 ml, depending on
           the concentration range expected, is used
5    Reagents
     5 1   Phosphate  buffer solution  Dissolve 24 g anhydrous  disodium hydrogen phosphate,
           Na2HPO4, and 46 g anhydrous potassium dihydrogen phosphate, KH2PO4, in distilled
           water Dissolve 800 mg  disodium ethylenediamme tetraacetate dihydrate in 100 ml
           distilled water  Combine these two solutions and dilute to 1 liter with distilled water
           Add 20 mg HgCl2 as a preservative
     5 2   N,N-Diethyl-p-phenylenediarmne (DPD) indicator solution Dissolve 1 g DPD oxalate
           or 1 5 g p-amino-N,N-diethylamlme sulfate in chlorine free distilled water containing 8
           ml of 1 + 3 H2SO4 and 200 mg disodium ethylenediamme tetraacetate dihydrate Dilute
           to 1 liter, store in a colored, glass-stoppered bottle Discard when discolored The buffer
           and indicator sulfate are available as a combined reagent in stable powder form
           CAUTION The oxalate is toxic, avoid ingestion

Approved for NPDES
Issued 1978

                                         3304-1

-------
      5 3  Standard  ferrous ammonium sulfate (FAS) titrant  Dissolve  1 106g Mohr's  salt
           Fe(NH4)2(SO4)26H2O, in distilled water containing 1 ml of 1 + 3 H2SO4 (5 4) and make
           up to 1 liter with freshly boiled and cooled distilled water Stable for one month  Check
           with titration by standard potassium dichomate (5 5) The FAS titrant is equivalent to
           lOOugCl/lOOml
      54  Sulfunc acid solution (1+3) Slowly add one part of H2SO4(sp gr 1 84) to three parts of
           distilled water
      5 5  Potassium dichromate (0 1OOON) Dissolve 4 904 g potassium dichromate (KaCraOy) in
           distilled water and dilute to 1 liter
      5 6  Potassium Iodide, KI Crystals
      5 7  Sodium Arsemte Solution  Place 500 mg of sodium arsemte (NaAsO2)  in a flask and
           dilute to 100 ml with distilled water
6     Procedure
      6 1   This procedure gives a convenient direct reading (ml titrant = mg/1 Cl) up to 4  mg/1
           An aliquot should be diluted to 100 ml if higher concentrations are present
      6 2  Place 5 ml of phosphate buffer (5 1) in a titration flask
      6 3  Add 5 ml of DPD indicator (5 2)
      6 4  Add approximately 1 g of KI (5 6) on a scoop
      6 5  Add 100 ml of sample
      6 6  Wait 2 minutes
      6 7  Titrate with FAS (5 3) until the red color is discharged Record the volume of titrant
           used
      6 8   If oxidized manganese is present
           681 Place 5 ml of phosphate buffer (5 1) in a titration flask
           682 Add one small crystal of potassium iodide (5 6)
           683 Add 0 5 ml of sodium arsemte solution (5 7)
           684 Add 100 ml of sample Mix
           685 Add 5 ml DPD indicator (5 2) Mix
           6.8 6 Titrate wth FAS (5 3) until the red color is discharged Record the volume of
                titrant used
7     Calculations
      7 1   The ml of FAS titrant is equal to the mg/1 Cl  If  oxidized manganese was  present,
           subtract the'amount of titrant used in 6 8 6 from the amount of titrant used in  6 7 to
           obtain the mg/1 Cl
8.     Precision and Accuracy
      Nineteen laboratories analyzed prepared samples  of 0 64 and 1 83 mg/1 Cl The relative
      standard deviations were 19 2 and 9 4% respectively and the relative errors were 8  1 and 4 3%
      respectively
                                        3304-2

-------
     In a single operator single laboratory situation the following results were obtained
    Sample
    Matrix

Distilled Water*
Drinking Water
River Water
Domestic  Sewage
Raw Sewage
 Average
   mg/1

  034
  065
  345
  098
  079
  108
  079
 Stand  Dev
    mg/l

    002
    0003
    002
    001
    001
    002
    003
Rel Stnd  Dev
      56
      05
      05
      12
      14
      18
      33

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                         CHLORINE,  TOTAL  RESIDUAL

                     Method  330.5  (Spectrophotometric, DPD)

                                                                STORET NO.  50060

     Scope and Application
     1 1   The  DPD-Colonmetric  method is  applicable to  natural  and treated waters at
           concentrations from 0 2-4 mg/1
     Summary of Method
     2 1   Chlorine  (hypochlonte ion,  hypochlorous  acid) and chlorammes stoichiometncally
           liberate iodine from potassium iodide at pH 4 or less
     2 2   The liberated iodine reacts with N,N-diethyl-p-phenylene diamine (DPD) to produce a
           red colored solution
     2 3   The solution is spectrophotometncally compared to a series of standards, using a graph
           or a regression analysis calculation
     2 4   The results are read or calculated into mg/1 Cl
     Interferences
     3 1   Any oxidizing agents, these are usually present at insignificant concentrations compared
           to the residual chlorine concentrations
     3 2   Turbidity and color will essentially prevent the colonmetric analysis
     Apparatus
     4 1   Spectrophotometer for use at 515 nm and cells of light path 1 cm or longer
     Reagents
     5 1   Phosphate buffer solution  Dissolve 24 g anhydrous disodium hydrogen  phosphate,
           Na2HPO4, and 46 g anhydrous potassium dihydrogen phosphate, KH2PO4, in distilled
           water Dissolve 800 mg  disodium  ethylenediamme tetraacetate dihydrate in  100 ml
           distilled water  Combine  these two solutions and dilute to 1  liter with distilled water
           Add 20 mg Hg Ci2 as a preservative
     5 2   N,N-Diethyl-p-phenylenediamme (DPD) indicator solution Dissolve 1 g DPD  oxalate
           or 1 5 g p-amino-N,N-diethylanihne sulfate in chlorine free distilled water containing 8
           ml of 1 +3 H2SO4 (5 3) and 200  mg disodium ethylenediamme tetraacetate dihydrate
           Dilute to 1 liter, store in a colored, glass-stoppered bottle  Discard when discolored  The
           buffer and indicator sulfate are available as a combined reagent in stable powder form
           CAUTION The oxalate is toxic, avoid mgestion
     5 3   Sulfunc acid solution (1+3)  Slowly add one part of H2SO4 (sp gr 1 84) to three parts
           of distilled water
     5 4   Potassium Iodide, KI crystals
     5 5   Stock Potassium Permanganate Solution Place 0 891 g KMnO4 m a volumetnc flask and
           dilute to 1 liter
Approved for  NPDES
Issued 1978

                                         330 5-1

-------
      5 6 '  Standard  Potassium Permanganate Solution  Dilute 10 00 ml of stock potassium
           permanganate splution (5 5) to 100 ml with distilled water in a volumetric flask One
           millihter of this solution diluted to 100 ml with distilled water is equivalent to 1 00 mg/1
           Cl
 6.    Procedure
      6 1  Calibration
           611 Prepare a series of permanganate standards covering the chlorine equivalent range
                of 005 to 4 mg/1
           6 1 2 Place 5 ml phosphate buffer (5  1) in a flask
           6 1 3 Add 5 ml DPD reagent (5 2)
           614 Add 100 ml permanganate standard (611)
           615 Read at 515 nm on a spectrophotometer and record the absorbance
           616 Return the contents of the cell to the flask
           617 Titrate the contents of the flask with standard ferrous ammonium sulfate (DPD-
                FAS Method), until the red color is discharged Record the result
      62  Sample Analysis
           6 2 1 Place 0 5 ml phosphate buffer (5 1) in flask
           622 Add 0 5 ml DPD reagent (5 2)
           623 Add approximately 0 1 g KI (5 4)
           624 Add 10 ml of sample
           625 Let stand 2 minutes
           626 Read at 515 nm on a spectrophotometer, and record the absorbance
7.    Calculations
      7.1   Calibration Curve Method
           711 Plot the absorbance of the standard permanganate solutions (6 1 5) on the vertical
                axis versus the titrated concentration (6 1 7) on the horizontal axis
           712 Draw the line of best fit through the points
           713 Locate the absorbance (6 2 6) of the sample on the vertical axis
           714 Read the concentration on the horizontal axis at the intersect of the  absorbance
                and the calibration line
      7.2   Regression Analysis Calculation-Computerized
           721 Enter the absorbance data of the standard permanganate solutions (6 1 5) and the
                respective titrated concentrations (6 1 7) in the appropriate places in the program
           722 Enter the absorbance data of the sample
           723 The computer will then display the concentration in mg/1 Cl
8     Precision and Accuracy
     Twenty-five laboratories analyzed prepared samples of 0 66 mg/1 Cl  The relative standard
     deviation was 27 6% and the relative error was 15 6%
                                        330 5-2

-------
     In a single laboratory, single operator situation the following results were obtained

    Sample              Average         Stnd  Deva          Rel Stnd Devi
    Matrix               mg/1              |mg/l          	%	
Distilled Water*          0 39               0 012                 31'
                        361               Oil                   32
Drinking Water         0 94               0 008                 08
River Water            0 86               0 02                   19
Domestic  Sewage        107               0 03                   24
      t                                 i-  jf
"Three replicates for distilled water Seven replicates for other samples
For three samples the results were compared to the lodometnc titration as a means of obtaining a
relative accuracy

                                                             s
    Sample             lodometnc           DPD              % Recovery
    Matrix             Titration          Colorime-
                         mg/1            tnc mg/1
Drinking Water          0 86               0 94                  109 3
River Water             0 70               0 86                  122 9
Domestic Sewage         101               107                  106 0
                                       Bibliography

     Standard Methods for the Examination of Water and Wastewater, 14th Ed, Pg  332, Method
     409F, "DPD Colonmetnc Method", (1975)
     Bender, D F, "Comparison of Methods for the Determination of Total Available Residual
     Chlorine in Various Sample Matrices", EPA Report-600/4-78-019
                                         330 5-3

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                CYANIDES, AMENABLE TO CHLORINATION

                  Method 335.1  (Titrimetric;  Spectrophotometric)

                                                                 STORET NO. 00722

      Scope and Application
      1 1   This method is applicable to the determination of cyanides amenable to chlormation in
           drinking, surface and saline waters, domestic and industrial wastes
      1 2   The titration procedure is used for measuring concentrations of cyanide exceeding 1
           mg/1  after removal of the  cyanides amenable to chlormation Below this level the
           colonmetnc determination is used
      Summary of Method
      21   A portion of the sample is chlorinated at a pH > 11 to decompose the cyanide  Cyanide
           levels in the chlorinated sample are then determined by the method for Cyanide, Total, m
           this manual Cyanides amenable to chlormation are then calculated by difference
      Reagents
      3 1   Calcium Hypochlonte solution Dissolve 5 g of calcium hypochlonte (Ca(OCl)2) in 100
           ml of distilled water
      3 2   Sodium Hydroxide solution Dissolve 50 g of sodium hydroxide (NaOH) in distilled
           water and dilute to 1 liter
      3 3   Ascorbic acid  crystals
      3 4   Potassium Iodide-starch test paper
      Procedure
      4 1   Two sample ahquots are required to determine cyanides amenable to chlormation To
           one 500 ml aliquot or a volume diluted to 500 ml, add calcium hypochlonte solution (3 1)
           dropwise while agitating and  maintaining the pH between 11 and 12 with sodium
           hydroxide (3 2)
           Caution The  initial reaction product of alkaline chlormation  is the  very toxic gas
           cyanogen chloride, therefore, it is recommended that this  reaction  be performed m a
           hood  For convenience, the sample may be agitated in a 1 liter  beaker by means of a
           magnetic stirring device
      4 2   Test for residual chlorine with Kl-starch paper (3 4) and maintain this excess for one
           hour, continuing agitation  A distinct blue color on the test paper indicates a sufficient
           chlorine level If necessary, add additional hypochlonte solution
      4 3   After one hour, add 0 5 g portions of ascorbic acid (3 3) until Kl-starch paper shows no
           residual chlorine Add an additional 0 5 g of ascorbic acid to insure the presence of excess
           reducing agent
      44   Test for total  cyanide in both the chlorinated and unchlormated  ahquots as in the
           method Cyanide, Total, in this manual
Approved for  NPDES
Issued 1974

                                         335 1-1

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5.    Calculation
      5.1   Calculate the cyanide amendable to chlormation as follows

           CN,mg/l = A-B

           where
           A = mg/1 total cyanide m unchlonnated aliquot
           B = mg/1 total in chlorinated aliquot

                                      Bibliography

1.    Annual Book of ASTM Standards, Part 31, "Water", Standard D 2036-75, Method B, p 505
     (1976)
2.    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 376 and 370,
     Method 413F and D (1975)
                                       335 1-2

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                                 CYANIDE,  TOTAL

                  Method 335.2 (Titrimetric;  Spectrophotometric)

                                                                STORET NO.  00720
                                                                       i
1    Scope and Application
     1 1   This method is applicable to the determination of cyanide in drinking, surface and saline
           waters, domestic and industrial wastes
    , 1 2   The titration  procedure  using silver nitrate with  p-dimethylammo-benzal-rhodanme
           indicator is used for measuring concentiations of cyanide  exceeding  1 mg/1 (0 25
           mg/250 ml of absorbing liquid)
     1 3   The colorimetnc procedure is used for concentrations below  1 mg/1 of cyanide and is
           sensitive to about 0 02 mg/1
2    Summary of Method
     2 1   The cyanide as hydrocyanic acid (HCN) is released from cyanide complexes by means of
           a reflux-distillation operation and absorbed m a scrubber containing sodium hydroxide
           solution The cyanide ion in the absorbing solution is then determined by volumetric
           titration or colonmetncally
     22   In the colonmetnc measurement the cyanide is converted to cyanogen chloride, CNC1,
           by reaction with chloramme-T at a pH less than 8 without hydrolyzmg to the cyanate
           After the reaction is complete, color is formed on the addition of pyridme-pyrazolone or
           pyridme-barbitunc acid reagent  The absorbance is read at 620 nm when using pyridme-
           pyrazolone or 578 nm for pyndme-barbitunc  acid  To obtain colors of comparable
           intensity,  it is essential to have the same salt content in both the  sample and the
           standards
     2 3   The titnmetnc measurement uses a standard solution of silver nitrate to titrate cyanide in
           the presence of a silver sensitive indicator
3    Definitions
     3 1   Cyanide is defined as cyanide ion and complex cyanides converted to hydrocyanic acid
           (HCN) by reaction in a reflux system of a mineral acid in the presence of magnesium ion
4    Sample Handling and Preservation
     4 1   The sample should be collected in  plastic or glass bottles of 1 liter or larger size  All
           bottles must be thoroughly cleansed and thoroughly rinsed to remove soluble material
           from containers
     4 2   Oxidizing agents such as  chlorine decompose most of the cyanides Test a drop of the
           sample with potassium iodide-starch test paper (Kl-starch paper), a blue color indicates
           the need for treatment Add ascorbic acid, a few crystals at a time, until a drop of sample
           produces no color on the indicator paper Then add an additional 0 06 g of ascorbic
           acid for each liter of sample volume

Approved for  NPDES
Issued  1974
Editorial revision 1974 and 1978
Technical Revision 1980
                                         335 2-1

-------
      4 3   Samples must be preserved with 2 ml of 10 N sodium hydroxide per liter of sample
           (pH > 12) at the time of collection
      4 4   Samples should be analyzed as rapidly as possible after collection If storage is required,
           the samples should be stored in a refrigerator or in an ice chest filled with water and ice to
           maintain temperature at 4C
5.    Interferences
      5 1   Interferences are eliminated or reduced by using the distillation procedure described
           in Procedure 8 1, 8 2 and 8 3
      5 2   Sulfides adversely  affect the colorimetric and titration procedures  Samples that
           contain hydrogen  sulfide,  metal sulfides or other compounds that may produce
           hydrogen sulfide during the distillation should be distilled by the optional procedure
           described in Procedure 8 2 The apparatus for this procedure is shown in Figure 3
      5 3   Fatty acids will distill and form soaps under the alkaline titration conditions, making the
           end point almost impossible to detect
           5 3 1 Acidify the sample with acetic acid (1 + 9) to pH 6 0 to 7 0
                Caution This operation must be performed in the hood and the sample left there
                until it can be made alkaline again after the extraction has been performed
           532 Extract with iso-octane, hexane, or chloroform (preference m order named) with a
                solvent volume equal  to 20% of the sample volume  One extraction is usually
                adequate to reduce the fatty acids below  the interference level Avoid multiple
                extractions or a long contact time at low pH in order to keep the loss of HCN at a
                minimum  When the extraction is completed, immediately raise the pH of the
                sample to above 12 with NaOH solution
      5.4   High results may be obtained for samples that contain nitrate and/or nitrite  During
           the distillation nitrate and nitrite will form nitrous acid which will react with some
           organic compounds to form oximes These compounds formed will decompose under
           test conditions to generate HCN The interference of nitrate and nitrite is eliminated
           b} pretreatment with sulfamic acid
6.    Apparatus
      6 1   Reflux distillation apparatus such as shown in Figure 1 or Figure 2  The boiling flask
           should be of 1 liter size with inlet tube and provision for condenser The gas absorber may
           be a Fisher-Milligan scrubber
      6 2   Microburet, 5 0 ml (for titration)
      6 3   Spectrophotometer suitable for measurements at 578 nm or 620 nm with a 1 0 cm cell or
           larger
      6 4   Reflux distillation apparatus for sulfide removal as shown in Figure 3  The boiling
           flask same as 6 1 The sulfide scrubber may be a Wheaton Bubber #709682 with 29/42
           joints, size 100 ml The air inlet tube should not be fritted  The cyanide absorption
           vessel should be the same as the sulfide scrubber The air inlet tube should be fritted
      6 5   Flow inetei, such as Lab Crest with stainless steel float (Fisher 11-164-50)
7.    Reagents
      7.1   Sodium hydroxide solution, 1 25N Dissolve 50 g of NaOH in distilled water, and dilute
           to 1 liter with distilled water
                                         335 2-2

-------
 7 2   Lead acetate Dissolve 30 g of Pb (C2H3O2)3H2O in 950 ml of distilled water Adjust
      the pH to 4 5 with acetic acid  Dilute to 1 liter
 7 5   Sulfunc acid, 18N  Slowly add 500 ml of concentrated H2SO4 to 500 ml of distilled
      water
 7 6   Sodium dihydrogenphosphate, 1  M Dissolve 138 g  of NaH2PO4-H2O m 1  liter of
      distilled water Refrigerate this solution
 7 7   Stock cyanide solution  Dissolve 2 51 g of KCN and 2 g KOH in 900 ml of distilled
      water Standardize with 0 0192 N AgNO3 Dilute to appropriate concentration so that
      1 ml = 1 mg CN
 7 8   Standard cyanide solution, intermediate Dilute 100 Oml of stock (1 ml = 1 mgCN)to
      1000 ml with distilled water (1 ml = 100 0 ug)                      ' ' '
 7 9   Working standard  cyanide  solution  Prepare fresh daily by diluting  100 0 ml of
      intermediate cyanide solution to 1000 ml with distilled water and store in a glass
      stoppered bottle 1 ml = 10 0 ug CN
 7 10  Standard silver  nitrate solution, 0 0192 N  Prepare by crushing approximately  5  g
      AgNO3 crystals and drying to constant weight at 40C Weigh out 3 2647 g of dried
      AgNO3, dissolve m distilled water, and dilute to 1000 ml (1 ml = Img CN)
 711  Rhodanme indicator Dissolve 20 mg of p-dimethyl-ammo-benzalrhodanme m 100 ml of
      acetone
 7 12  Chloramme T solution Dissolve 1 0 g of white, water soluble Chloramme T in 100 ml of
      distilled water and refrigerate until ready to use  Prepare fresh daily
 713  Color Reagent  One of the following may be used
      7131      Pyndme-Barbitunc Acid Reagent  Place 15 g of barbituric acid in a 250 ml
                volumetric flask and add just enough distilled water to wash the sides of the
                flask and wet the barbituric acid  Add 75 ml of pyndme and mix Add 15 ml
                of cone  HC1, mix, and cool to room temperature Dilute to 250 ml with
                distilled water and mix This reagent is stable for approximately six months
                if stored in a cool, dark place
      7 13 2      Pyndme-pyrazolone solution
          71321   3-Methyl-l-phenyl-2-pyrazolm-5-one reagent, saturated solution Add
                     0 25 g of 3-methyl-l-phenyl-2-pyrazolm-5-one to 50 ml of distilled
                     water, heat to 60C with stirring Cool to room temperature
          71322   3,3'Dimethyl-l, l'-diphenyl-[4,4'-bi-2 pyrazolme]-5,5'dione (bispyra-
                     zolone) Dissolve 0 01 g of bispyrazolone m 10 ml of pyndme
          71323   Pour solution (7 13 2 1) through non-acid-washed filter paper Collect
                     the filtrate Through the same  filter paper pour solution (71322)
                     collecting the filtrate in the same container as filtrate from (7 13 2 1)
                     Mix until the filtrates are homogeneous The mixed reagent develops a
                     pink color but this does not affect the color production with cyanide if
                     used within 24 hours of preparation
7 14  Magnesium chloride solution Weight 510 g of MgCl26H2O into a 1000 ml flask, dissolve
      and dilute to 1 liter with distilled water
715  Sulfamic acid i
                                   335 2-3

-------
8.    Procedure
     8 I   For samples without sulfide
          8 1 1    Place 500 ml of sample, or an aliquot diluted to 500 ml in the 1 liter boiling
                 flask  Pipet 50 ml of sodium hydroxide (7 1) into the absorbing tube  If the
                 apparatus in Figure 1 is used, add distilled water until the spiral is covered
                 Connect the boiling flask, condenser, absorber and trap in the train (Figure 1
                 or 2)
          812    Start a slow stream of air entering the boiling flask by adjusting the vacuum
                 source Adj ust the vacuum so that approximately two bubbles of air per second
                 enters the boiling flask through the air inlet tube Proceed to 8 4
     8 2   For samples that contain sulfide
          8.2 1    Place 500 ml of sample, or an aliquot diluted to 500 ml in the 1 liter boiling
                 flask PipetSO ml of sodium hydroxide (7 1) to the absorbing tube Add25mlof
                 lead acetate (7 2) to the sulfide scrubber Connect the boiling flask, condenser,
                 scrubber and absorber in the train (Figure 3) The flow meter is connected to the
                 outlet tube of the cyanide absorber
          822    Start a stream of air entering the boiling flask by adjusting the vacuum source
                 Adjust the vacuum so  that approximately  1 5 liters per minute enters  the
                 boiling flask through the air inlet tube  The bubble rate may not remain
                 constant while heat is being applied to the flask It may be necessary to readjust
                 the air rate occasionally Proceed to 8 4
     83   If samples contain NO3 and or NO2 add 2 g of sulfamic acid solution (7 15) after the air
          rate is set through the air inlet tube Mix for 3 minutes prior to addition of H2SO4
     8 4   Slowly add 50 ml 18N sulfunc acid (7 5) through the air inlet tube Rinse the tube with
          distilled water and allow the airflow to mix the flask contents for 3 mm Pour 20 ml of
          magnesium chloride (7 14) into the air inlet and wash down with a stream of water
     8 5   Heat  the solution to boiling Reflux for one hour Turn off heat and continue  the
          airflow for at least 15  minutes After cooling the boiling flask, disconnect absorber and
          close off the vacuum source
     8 6   Drain the solution from the absorber into a 250 ml volumetric flask Wash the absorber
          with distilled water and add the washings to the flask  Dilute to the mark with distilled
          water
     8 7   Withdraw 50 ml or less of the solution from the flask and transfer to a 100 ml volumetric
          flask  If less than 50 ml is taken, dilute to 50 ml with 0 25N sodium hydroxide solution
         (7 4) Add 15 0 ml of sodium phosphate solution (7 6) and mix
         871    Pyridme-barbituric acid method Add 2 ml of chloramme T (7 12) and mix
                 See Note 1 After 1 to 2 minutes, add 5 ml of pyndine-barbitunc acid solution
                 (7 13 1) and mix  Dilute to mark with distilled water and mix again Allow 8
                 minutes for color development then read absorbance at 578 nm in a 1 cm cell
                 within 15 minutes
         872    Pyridine-pyrazolene method Add 0 5 ml of chloramme T (7 12) and mix See
                 Note 1 and 2  After 1 to 2 minutes add 5 ml of pyndme-pyrazolone solution
                                             3352-4

-------
            (7 13 1) and mix  Dilute to mark with distilled water and mix again After 40
            minutes read absorbance at 620 nm in a 1 cm cell
            NOTE 1   Some  distillates  may  contain  compounds  that have a chlorine
                      demand  One minute after the  addition of chloramme T, test for
                     residual chlorine with Kl-starch  paper If the test is negative, add an
                     additional 0 5 ml of chlorine T After one minute, recheck the sample
            NOTE 2  More than 05  ml of chloramme T will prevent  the color from
                     developing with pyridme-pyrazolone
8 8   Standard curve for samples without sulfide
     881   Prepare a series of standards by pipetmg suitable volumes of standard solution
            (7 9)  into 250 ml volumetric flasks  To each standard add 50 ml  of 1 25 N
            sodium hydroxide and dilute to 250 ml with distilled water Prepare as follows

              ML of Workmg Standard Solution              Cone, fjg CN
                     (1 ml = 10 fjg CN)                      per 250 ml
                             0                                BLANK
                             10                                 10
                             20                                 20
                             50                                 50
                            100                                100
                            15 0                                150
                            20 0                                200
     882   It is not imperative that all standards be distilled in the same manner as the
            samples It is recommended that at least two standards (a high and low) be
            distilled and compared to similar values on the curve to insure that the distil-
            lation technique is reliable If distilled standards do not agree within 10%
            of the undistilled standards the analyst should find the cause of the apparent
            error before proceeding
     883   Prepare a standard curve  by plotting absorbance of standard  vs cyanide
            concentrations
     884   To check the efficiency of the sample distillation, add an increment of cyanide
            from either the intermediate standard (7 8) or the working standard (7 9) to
            500 ml of sample to insure a level of 20 //g/1  Proceed with the analysis as in
            Procedure (811)
8 9  Standard curve for samples with sulfide
     891   It is imperative that all standards be distilled in the same manner as the samples
            Standards distilled by this method will give a linear curve, but as the concen-
            tration increases, the recovery  decreases  It is recommended that at least 3
            standards be  distilled
     892   Prepare a standard curve by plotting absorbance of standard vs cyanide con-
            centrations
                                  335 2-5

-------
8 10 Titrimetric method
     8101  If the sample contains more than 1 mg/1 of CN, transfer the distillate or a
           suitable aliquot diluted to 250 ml, to a 500 ml Erlenmeyer flask Add 10-12 drops
           of the benzalrhodanme indicator
    8102  Titrate with standard silver nitrate to the first change in color from yellow to
           brownish-pink Titrate a distilled water blank using the same amount of sodium
           hydroxide and indicator as in the sample
    8.103  The analyst should familiarize himself with the end point of the titration and the
           amount of indicator to be used before actually titrating the samples.
 Calculation
 91  If the colonmetnc procedure is used, calculate the cyanide, in ug/1, in the original
      sample as follows

                              CN.zig/1 =  A x 1,000 x 50
                                            B        C

         where

         A = ug CN read from standard  curve
         B = ml of original  sample for distillation
         C = ml taken for colonmetnc analysis
                                    335 2-6

-------
     9 2  Using the titnmetnc procedure, calculate concentration of CN as follows
        *        -*-il y^T-inr c>o**^^l^
                                          250
                 ml ong sample     ml of aliquot titrated

          where

          A = volume of AgNO3 for titration of sample
          B = volume of AgNO3 for titration of blank

10   Precision and Accuracy
     10 1 In a single laboratory (EMSL), using mixed industrial and domestic waste samples at
          concentrations of 006, 0 13, 028 and 062 mg/1 CN, the standard deviations were
          0005, 0007,  0031  and 0094, respectively.
     10 2 In a single laboratory (EMSL), using mixed industrial and domestic waste samples at
          concentrations of 0 28 and 0 62 mg/1 CN, recoveries were 85% and 102%, respectively

                                      Bibliography

1    Bark, L S, and Higson, H G  "Investigation of Reagents for the Colonmetric Determination
     of Small Amounts of Cyanide", Talanta, 2 471-479 (1964)
2    Elly, C T "Recovery of Cyanides by Modified Serfass Distillation" Journal Water Pollution
     Control Federation 40 848-856(1968)
3    Annual Book of ASTM Standards, Part 31, "Water", Standard D2036-75, Method A, p 503
     (1976)
4    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 367 and 370,
     Method 413B and D (1975)
5    Egekeze, J  O , and Oehne, F  W , "Direct Potentiometric Determination of Cyanide in
     Biological Materials," J Analytical Toxicology, Vol 3, p 119, May/June 1979
6    Casey, J P , Bright, J  W , and Helms, B D  , "Nitrosation Interference in Distillation Tests
     for Cyanide," Gulf Coast Waste Disposal Authority, Houston, Texas
                                        335 2-7

-------
ALLIHN CONDENSER 

AIR INLET TUBE^

             0
ONE LITER	
BOILING FLASK
                            CONNECTING TUBING
                                    SUCTION
                 FIGURE 1
   CYANIDE DISTILLATION APPARATUS
                  335 2-8

-------
   COOLING WATER
   INLET
SCREW CLAMP
     )
     &
        HEATER-*
                                   TO  LOW VACUUM
                                      SOURCE
                                 ABSORBER
                           DISTILLING FLASK
             FIGURE 2
CYANIDE DISTILLATION  APPARATUS
                 335 2-9

-------
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                                 CYANIDE,  TOTAL

                   Method 335.3  (Colorimetric, Automated UV)

                                                                 STORET  NO.  00720
     Scope and Application
     1 1  This method is applicable to the determination of cyanide in drinking and surface waters,
          domestic and industrial wastes
     1 2  The applicable range is 5 to 500 ug/1
     Summary of Methods
     2 1  The cyanide as hydrocyanic acid (HCN), is released from cyanide complexes by means of
          UV digestion and distillation Cyanides are converted to cyanogen chloride by reactions
          with chloramme-T which subsequently reacts with pyridme and barbituric acid to give a
          red-colored complex
     Sample Handling and Preservation
     3 1  The sample should be collected in plastic bottles of 1 liter or larger size All bottles must
          be  thoroughly cleansed and  thoroughly rinsed  to remove soluble  material from
          contamers
     3 2  Samples must be preserved with 2ml of 10 N sodium hydroxide per liter of sample (pH
           > 12) at the time of collection
     ,3 3  Samples should be analyzed as rapidly as possible after collection If storage is required,
          the samples should be stored in a refrigerator or in an ice chest filled with water and ice to
         - maintain temperature at 4C
     3 4  Oxidizing agents such as chlorine decompose most  of the cyanides Test a drop  of the
          sample with potassium iodide-starch test paper (KI starch paper), a blue color indicates
          the need for treatment Add ascorbic acid, a few crystals at a time, until a drop of sample
          produces no color on the indicator paper Then add an additional 0 6 g of ascorbic acid
          for each liter of sample volume
     Interferences
     4 1  Thiocyanates  are a positive interference  During the  UV digestion thiocyanates are
          decomposed to cyanide
     4 2  Sulfides adversely affect  the colonmetnc procedure If a drop of the sample on lead
          acetate  test paper indicates the presence of sulfide,  treat  25 ml more of the stabilized
          sample  (pH  > 12) than  that required for the cyanide determination with  powdered
          cadmium carbonate Yellow cadmium sulfide precipitates  if the sample contains sulfide
          Repeat this operation until a drop of the treated sample solution does not darken the lead
          acetate  test paper  Filter the solution through a dry filter paper into a dry beaker, and
          from the filtrate,  measure the sample to be used for analysis Avoid a  large excess of
Issued 1978

                                         335 3-1

-------
           cadmium  and a long contact time m order to minimize a loss by complexation  or
           occlusion of cyanide on the precipitated material
 5.    Apparatus
      5 1   Techmcon AutoAnalyzer
           511 Sampler
           512 Manifold with UV digestor
           513 Proportioning pump
           514 Heating bath with distillation coil
           5 1 5 Distillation head
           5 1 6 Colorimeter equipped with a 15 mm flowcell and 570 nm filter
           5 1 7 Recorder
 6.    Reagents
      6 1   Distillation reagent  Carefully add 250 ml of 85% phosphoric acid and  50 ml  of
           hypophosphorus acid to 700 ml of distilled water, mix and dilute to one liter with
           distilled water
      6 2   Phosphate buffer, pH 5 2 Dissolve 13 6 g of potassium dihydrogen phosphate and 0 28 g
           of disodium phosphate in 900 ml of distilled water and dilute to one liter
      6 3   Chloramme-T Dissolve 2 0 g of chloramme-T in 500 m 1 of distilled water
      6 4   Pyndme barbituric acid reagent Place 15 g of barbituric acid in a one liter beaker Wash
           the sides of the beaker with about 100 ml of distilled water Add 75 ml of pyndme and
           mix Add 15 ml of cone  HC1 and mix Dilute to about 900 ml with distilled water and
           mix until all the barbituric acid has dissolved Transfer the solution to a one liter flask
           and dilute to the mark
      6 5   Sodium hydroxide, 1 N Dissolve 40 g of NaOH in 500 m 1 of distilled water and dilute to
           one liter
      6 6   Stock cyanide solution Dissolve 251 g of KCN and 2 g KOH m 900 ml of distilled
           water and mix Dilute to one liter Standardize with 0 0192 N AgNO3 to appropriate
           concentration 1 ml = 1 mgCN
      6 7   All working standards should contain 2 m 1 of 1 N NaOH (6 5) per 100 m 1
7.    Procedure
      7.1   Set up the manifold as shown in Figure 1 m a hood or a well-ventilated area
      7 2   Set temperature of the heating bath at 150C
      7 3   Allow colorimeter and recorder to warm up for 30 minutes Run a baseline with all
           reagents, feeding distilled water through the sample line
      74   Place appropriate standards in the sampler  in  order  of decreasing concentration
           Complete loading of sampler tray with unknown samples
      7 5   When the baseline becomes steady begin the analyses
8.    Calculation
      8 1   Prepare standard curve by plotting peak heights of standards  against concentration
           values  Compute concentrations of samples by comparing sample peak heights with
           standards
9.    Precision and Accuracy
      9 1   Precision and accuracy data are not available at this time
                                         335 3-2

-------
                           Bibliography

Technicon AutoAnalyzer II Methodology, Industrial Method No  315-74 WCUV digestion
and distillation, Technicon Industrial Systems, Tarrytown, N Y, 10591, (1974)
Goulden,P D, Afghan, B K and Brooksbank, P , Anal Chem^4,1845 (1972)
                             335 3-3

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                                    335 3-4

-------
                              FLUORIDE,  TOTAL

       Method 340.1 (Colorimetric, SPADNS with Bellack Distillation)

                                                        STORET NO.  Total  00951
                                                                    Dissolved  00950

    Scope and Application
    1 1  This method is applicable to the measurement of fluoride in drinking, surface, and saline
         waters, domestic and industrial wastes
    1 2  The method covers the range from 0 1 to about 1 4 mg/1 F  This range may be extended
         to  1000 mg/1 using the Fluoride Ion  Selective Electrode Method (3402)  after
         distillation
    Summary of Method
    2 1  Following distillation to remove interferences, the sample is treated with the SPADNS
         reagent  The loss of color resulting from the  reaction of fluoride with the zirconyl-
         SPADNS dye is a function of the fluoride concentration
    Comments
    3 1  The SPADNS reagent is more tolerant of interfering matenals than other accepted
         fluoride  reagents  Reference to Table 414 1,  p  388,  Standard Methods  for the
         Examination of Waters and Wastewaters,  14th Edition, will help the analyst decide if
         distillation is required  The addition of the highly colored SPADNS reagent must be
         done with utmost accuracy because the fluoride concentration is measured as a difference
         of absorbance in the blank and the sample  A small error in reagent additon is the most
         prominent source of error in this test
    3 2   Care must be taken to avoid overheating the flask above the level of the solution This is
          done by maintaining an even flame entirely under the boiling flask
    Apparatus
    4 1   Distillation apparatus  A  1-liter  round-bottom,  long-necked  pyrex boiling flask,
          connecting tube, efficient condenser, thermometer adapter and thermometer reading to
          200C All connections should be ground glass  Any apparatus equivalent to that shown
          in Figure 1 is acceptable
     42   Colorimeter One of the following
          421 Spectrophotometer for use at 570 nm providing a light path of at least 1 cm
          422 Filter photometer equipped  with a greenish  yellow  filter having  maximum
               transmittance at 550 to 580 nm and a light path of at least 1 cm
     Reagents
     5 1   Sulfunc acid, H2SO4, cone
Approved for NPDES  and SDWA
Issued 1971
Editorial revision 1974 and 1978

                                        340 1-1

-------
 5 2   Silver sulfate, Ag2SO4 crystals
 5 3   Stock fluoride solution Dissolve 0 221 g anhydrous sodium fluoride, NaF, in distilled
       water m a 1-liter volumetric flask and dilute to the mark with distilled water, 1 00 ml =
       0 ImgF
 5 4   Standard  fluoride solution  Place 100 ml stock fluoride solution  (5 3) in a 1 liter
       volumetric flask and dilute to the mark with distilled water, 1 00 ml = 0 010 mg F
 5 5   SPADNS solution Dissolve 0 958 g SPADNS, sodium  2-(parasulfophenylazo)-l,8-
       dmydroxy-3,6-naphthalene disulfonate, in distilled water in a 500 ml volumetric flask
       and dilute to the mark Stable indefinitely if protected from direct sunlight
 5 6   Zirconyl-acid reagent Dissolve 0 133 g zirconyl chloride octahydrate, ZrOCl28H2O m
       approximately 25 ml distilled water in a 500 ml volumetric flask  Add 350 ml cone HC1
       and dilute to the mark with distilled water
 5.7   Acid-zirconyl-SPADNS reagent Mix equal volumes of SPADNS solution (5 5) and
       zirconyl-acid reagent (5 6) The combined reagent is stable for at least 2 years
 5 8   Reference solution Add 10 ml SPADNS solution (5 5) to 100 ml distilled water Dilute 7
       ml cone HC1 to 10 ml and add to the dilute SPADNS solution  This solution is used for
      zeroing the spectrophotometer or photometer It is stable and may be used indefinitely
 5 9  Sodium arsenite solution Dissolve 5 0 g NaAsO2 m distilled water in a 1-liter volumetric
      flask and dilute to the mark with distilled water (CAUTION Toxic-avoid mgestion)
 Procedure
 6 1   Preliminary distillation
      611 Place 400 ml distilled water m the distilling flask
      6 1 2 Carefully add 200 ml cone H2SO4 and swirl until contents are homogeneous
      613 Add 25 to 35 glass beads, connect the apparatus (Figure  1) making sure all joints
           are tight
      6 1 4 Heat slowly at first, then as rapidly as the efficiency of the  condenser will permit
           (distillate must be cool) until the temperature of the flask contents reaches exactly
           180C  Discard the distillate  This  process removes fluoride  contamination and
           adjusts the acid-water ratio for subsequent distillations
      6 1 5 Cool to  120C or below
      6 1 6 Add 300 ml sample, mix thoroughly, distill as in 6  1 4 until temperature reaches
           180C Do not heat above 180C to prevent sulfate carryover
      617 Add Ag2SO4 (5 2) at a rate of 5 mg/mg Cl when high chloride samples are distilled
      618 Use the sulfunc acid solution m the flask repeatedly until the contaminants  from
           the samples accumulate to such an extent that recovery is affected or interferences
           appear in the distillate Check periodically by distilling standard fluoride samples
      6 1 9 High fluoride samples may require that the still be flushed by using distilled water
           and combining distillates
6 2   Colonmetnc Determination
      621 Prepare fluoride standards in the range 0 to 1 40 mg/1 by diluting appropriate
           quantities of standard fluoride solution (5 4) to 50 ml with distilled water
                                    340 1-2

-------
              CONNECTING TUBE
        THERMOMETER ;
THERMOMETER ADAPTER
             1-liter
   ROUND BOTTOM
        FLASK
ADAPTER
                          24/40
                           JOINT
            CONDENSER
              BURNER
                                       3 00-ml
O                                       VOLUMETRIC
                                       FLASK

     FIGURE 1  DIRECT DISTILLATION APPARATUS
               FOR FLUORIDE.
                      340 1-3

-------
            622 Pipet 5 00 ml each of SPADNS solution (5 5) and zirconyl-acid reagent (5 6) or
                 10 00 ml of the mixed acid-zirconyl-SPADNS reagent (5 7) to each standard and
                 mix well
            623 Set photometer to zero with reference  solution  (5 8)  and immediately obtain
                 absorbance readings of standards
            624 Plot  absorbance versus concentration  Prepare a new standard curve whenever
                 fresh reagent is made
            6 2 5 If residual chlorine is present pretreat the sample with 1 drop (0 05 ml) NaAsO2
                 solution (5 9) per  0 1  mg  residual  chlorine  and   mix  Sodium arsemte
                 concentrations of 1300 mg/1 produce an error of 0 1 mg/1 at 1 0 mg/1 F
            6 2 6 Use a 50 ml sample or a portion diluted to 50 ml  Adjust the temperature of the
                 sample to that used for the standard curve
            627 Perform step 6 2 2and 6 2 3
 7.    Calculations
      7 1   Read the concentration in the 50 ml sample using the standard curve (6 2 4)
      7 2   Calculate as follows
           mg/1 F =      x
             8
                      ml sample

      7 3  When a sample (ml sample) is diluted to a volume (B) and then a portion (C) is analyzed,
           use
              A F = mgFx  1,000   B
             6       ml sample    C

 8.    Precision and Accuracy
      81   On a sample containing 0 83 mg/1 F with no interferences, 53 analysts using the Bellack
           distillation and the SPADNS reagent obtained a mean of 0 81 mg/1 F with a standard
           deviation of 0089 mg/1
      82   On a sample containing 057 mg/1 F (with 200 mg/1 SO4 and 10 mg/1 Al  as
           interferences) 53 analysts using the Bellack distillation obtained a mean of 0 60 mg/lF
           with a standard deviation of 0 103 mg/1
      83   On a sample containing 0 68 mg/1 F (with 200 mg/1 SO4, 2 mg/1 Al and 2 5 mg/1
           [Na(PO3)6] as interferences), 53 analysts using the Bellack distillation obtained a mean of
           0.72 mg/1 F with a standard deviation of 0 092 mg/1 (Analytical Reference Service,
           Sample 111-B water, Fluoride, August, 1961)

                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater, p 389-390 (Method No
     414A, Preliminary Distillation Step) and p 393-394 (Method 414C SPADNS) 14th Edition
     (1975)
2    Annual Book of ASTM Standards,  Part 31, "Water", Standard D 1179-72, Method A, p 310
     (1976)

                                        3401-4

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                                    FLUORIDE

            Method 340.2 (Potentiometric, Ion Selective Electrode)

                                                         STORET NO: Total  00951
                                                                     Dissolved  00950

     Scope and Application
     1  1   This method is applicable to the measurement of fluoride m drinking, surface and saline
          waters, domestic and industrial wastes
     1  2   Concentration of fluoride from 0 1 up to 1000 mg/liter may be measured
     1  3   For Total or Total Dissolved Fluoride, the Bellack distillation is required for NPDES
          monitoring but is not required for SDWA monitoring
     Summary of Method
     2  1   The fluoride is determined potentiometncally using a fluoride electrode m conjunction
          with a standard single junction sleeve-type reference electrode and a pH meter having an
          expanded millivolt scale or a selective ion meter having a direct concentration scale for
          fluoride
     2  2   The fluoride electrode consists of a lanthanum fluoride crystal across which a potential is
          developed by fluoride ions The cell may be represented by Ag/Ag  Cl, Cr(0 3),
          F(0 001) LaF/test solution/SCE/
     Interferences
     3  1   Extremes of pH interfere,  sample pH should be between 5 and 9  Polyvalent cations of
          Si+4, Fe+3 and Al+3 interfere by forming  complexes with fluoride  The degree of
          interference depends  upon  the  concentration  of  the  complexmg  cations, the
          concentration of fluoride  and the pH of the sample The addition of a pH 5 0 buffer
          (described  below) containing  a strong chelating agent  preferentially complexes
          aluminum (the most common  interference), silicon and iron and eliminates the pH
          problem
     Sampling Handling and Preservation
     4 1   No special requirements
     Apparatus
     5  1   Electrometer (pH meter),  with expanded mv scale, or a selective ion meter such as the
          Orion 400 Series
     5  2   Fluoride Ion Activity Electrode, such as Orion No 94-09(I>
     5 3   Reference electrode, single junction, sleeve-type, such as Orion No 90-01, Beckman No
          40454, or Corning No 476010
     5 4   Magnetic Mixer, Teflon-coated stirring bar
Approved for  NPDES and SDWA
Issued 1971
Editorial revision 1974

                                         340 2-1

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  6    Reagents
       6.1   Buffer solution, pH 5 0-5 5 To approximately 500 ml of distilled water in a 1 liter beaker
            add 57 ml of glacial acetic acid, 58 g of sodium chloride and 4 g of CDTA<2) Stir to
            dissolve and cool to room temperature Adjust pH of solution to between 5 0 and 5 5 with
            5 N sodium hydroxide (about 150 ml will be required)  Transfer solution to a 1 liter
            volumetric flask and dilute to the mark with distilled water For work with  brines,
            additional Nad should be added to raise the chloride level to twice the highest expected
            level of chloride in the sample
       6.2   Sodium fluoride, stock solution 1 0 ml = 0 1 mg F  Dissolve 0 2210 g of sodium fluoride
            in distilled water and dilute to 1  liter in a volumetric flask Store in chemical-resistant
            glass or polyethylene
       6 3   Sodium  fluoride, standard solution  10ml  = 001mgF Dilute 1000 ml of sodium
            fluoride stock solution (6 2) to 1000 ml with distilled water
       6 4   Sodium  hydroxide, 5N Dissolve 200 g sodium hydroxide in distilled water, cool and
            dilute to 1 liter
 7.    Calibration
       7.1   Prepare a series of standards using the fluoride standard solution (6 3) in the range of 0 to
            2 00 mg/1  by diluting appropriate volumes to 50 0 ml The following series may be used
                                                                             i  i|

                 Millimeters of Standard                       Concentration when Diluted
                 (1 0  ml = 0 01 mg/F)                          to 50 ml, mg F/hter

                        000                                           000
                        100                                           020
                        200                                           040
                        300                                           060
                        400                                           080
                        500                                           100
                        600                                           120
                        800                                           160
                       1000                                           200

      7 2   Calibration of Electrometer Proceed as described in (8 1) Using semiloganthmic graph
           paper, plot the concentration of fluoride in mg/hter on the log axis vs  the electrode
           potential developed in  the standard on the linear axis,  starting with  the lowest
           concentration at the bottom of the scale  Calibration of a selective ion meter Follow the
           directions of the manufacturer for the operation of the instrument
8     Procedure
      8 1   Place 50 0 ml of sample or standard solution and 50 0 ml of buffer (See Note) in a 150 ml
           beaker Place on a magnetic stirrer and mix at medium speed Immerse the electrodes in
           the solution and observe the meter reading while mixing  The electrodes must remain in
           the solution  for  at least  three  minutes or until the  reading  has stabilized  At
           concentrations under 0 5 mg/liter F, it may require as long as five minutes to reach a
           stable meter reading, high concentrations stabilize more quickly If a pH meter is used,
           record the potential measurement  for each unknown sample and convert  the potential
                                          3402-2

-------
          reading to the fluoride ion concentration of the unknown using the standard curve  If a
          selective ion meter is used, read the fluoride level in the unknown  sample directly in
          mg/1 on the fluoride scale
          NOTE: For industrial waste samples, this amount of buffer  may not be adequate
          Analyst should check pH first If highly basic ( >9), add 1 N HC1 to adjust pH to 8 3
9    Precision and Accuracy
     91  A synthetic sample prepared by the Analytical Reference Service, PHS, containing 0 85
          mg/1 fluoride and no interferences was analyzed by 111 analysts, a mean of 0 84 mg/1
          with a standard deviation of 0 03 was obtained
     92  On the same  study,  a synthetic sample containing 0 75 mg/1 fluoride, 2 5  mg/1
          polyphosphate and 300 mg/1 alkalinity, was analyzed by the same 111 analysts, a mean
          of 0 75 mg/1 fluoride with a standard deviation of 0 036 was obtained

                                     Bibliography

1    PatentNo 3,431,182(March4,1969)
2    CDTA is the abbreviated designation of 1,2-cyclohexylene dimtnlo tetraacetic acid  (The
     monohydrate form may also be used ) Eastman Kodak 15411, Mallmckrodt2357, Sigma D
     1383, Tridom-Fluka 32869-32870 or equivalent
3    Standard Methods for the Examination of Water and Wastewaters, p 389, Method No 414A,
     Preliminary Distillation Step (Bellack), and p 391, Method No 414B, Electrode Method, 14th
     Edition (1975)
4    Annual Book of ASTM Standards, Part 31, "Water", Standard D1179-72, Method B, p 312
     (1976)
                                        340 2-3

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                                     FLUORIDE

              Method 340.3 (Colorimetric, Automated  Complexone)

                                                        STORET  NO. Total 00951
                                                                     Dissolved 00950

     Scope and Application
     1 1  This method is applicable to drinking, surface and saline waters, domestic and industrial
          wastes The applicable range of the method is 0 05 to 1 5 mg F/l Twelve samples per
          hour can be analyzed
     1 2  For Total or Total Dissolved Fluoride, the Bellack Distillation must be performed on the
          samples prior to analysis by the complexone method
     Summary of Method
     2 1  Fluoride ion reacts with the red cerous chelate of alizarin complexone It is unlike other
          fluoride procedures in that a positive color is developed as contrasted to a bleaching
          action in previous methods
     Sample Handling and Preservation
     3 1  No special requirements
     Interferences
     4 1  Method is free from most amonic and cationic interferences, except aluminum, which
          forms an extremely stable fluoro compound, A1F6"3   This is overcome by treatment
          with 8-hydroxyqumoline to complex the aluminum and by subsequent extraction with
          chloroform  At aluminum levels below 0 2 mg/1, the extraction procedure is not
          required
     Apparatus
     5 1  Techmcon AutoAnalyzer Unit consisting of
          5 1 1 Sampler I
          5 1 2 Manifold
          513 Proportioning pump
          514 Continuous filter
          515 Colorimeter equipped with 15 mm tubular flow cell and 650 nm filters
          516 Recorder equipped with range expander
     Reagents
     6 1  Sodium acetate solution Dissolve 272 g (2 moles) of sodium acetate in distilled water and
          dilute to 1 liter
     6 2  Acetic acid-8-hydroxyquinohne solution Dissolve 6 g of 8-hydroxyqumoline in 34 ml of
          cone acetic acid, and dilute to 1 liter with distilled water
Approved for NPDES
Issued  1971
                                        340 3-1

-------
 6 3   Chloroform Analytical reagent grade
 6.4   Ammonium acetate solution (6 7%) Dissolve 67 g of ammonium acetate in distilled
      water and dilute to 1 liter
 6 5   Hydrochloric acid (2 N) Dilute 172 ml of cone HC1 to 1 liter
 6 6   Lanthanum alizarin fluoride blue solution"' Dissolve 0 18 g of alizarin fluoride blue in a
      solution containing 0 5 ml of cone ammonium hydroxide and 15 ml of 6 7% ammonium
      acetate (6 4) Add a solution that contains 41 g of anhydrous sodium carbonate and 70 ml
      of glacial acetic acid in 300 ml of distilled water Add 250 ml of acetone Dissolve 0 2 g of
      lanthanum oxide in 12 5 ml of 2 N hydrochloric acid (6 5) and mix with above solution
      Dilute to 1 liter
 6 7   Stock solution Dissolve 2 210 g of sodium fluoride in 100 ml of distilled water and dilute
      to 1 liter in a volumetric flask 1 0 ml =  10 mg F
 6 8   Standard Solution Dilute 10 0 ml of stock solution  to 1 liter in a volumetric flask 1 0
      ml  = OOlmgF
      6 8  1 Using standard solution, prepare  the following standards in 100 ml volumetric
           flask
                   mg F/l                              ml Standard Solution/100 ml

                    005                                          05
                    010                                           10
                    020                                          20
                    040                                          40
                    060                                          60
                    080                                          80
                    100                                          100
                    1 20                                          12 0
                    1 50                                          150
Procedure
7.1   Set up manifold as shown m Figure 1
7 2   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
      reagents,  feeding distilled water through the sample line  Adjust dark current and
      operative opening on colorimeter to obtain stable baseline
7 3   Place distilled water wash tubes in alternate openings in Sampler and set sample timing
      at 2 5 minutes
7 4   Arrange fluoride standards in Sampler in order of decreasing concentration  Complete
      loading of Sampler tray with unknown samples
7 5   Switch sample line from distilled water to Sampler and begin analysis
Calculation
8 1   Prepare standard curve by plotting peak heights of processed fluoride standards against
      concentration values Compute concentration  of samples by comparing sample peak
      heights with standard curve
                                    340 3-2

-------
9    Precision and Accuracy
     91   In a single laboratory (EMSL), using surface water samples at concentrations of 0 06,
           0 15, and 1 08 mg F/l, the standard deviation was +0 018
     92   In a single laboratory (EMSL), using surface water samples at concentrations of 0 14 and
           1 25 mg F/l, recoveries were 89% and 102%, respectively

                                      Bibliography

1    J T Baker Laboratory Chemical No Jl 12 or equivalent
2    Greenhaigh, R ,  and Riley, J P ,  "The Determination of Fluorides in Natural Waters, with
     Particular Reference to Sea Water" Anal Chim Acta,25, 179(1961)
3    Chan, K M , and Riley, J  P , "The Automatic Determination of Fluoride m Sea Water and
     Other Natural Water"  Anal Chim Acta, 35, 365(1966)
4    Standard Methods for the Examination of Water and Wastewater, 14th  Edition,  p 614,
     Method 603, (1975)
                                        340 3-3

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3403-4

-------
                                        IODIDE

                              Method 345.1 (Titrimetric)

                                                                 STORET NO. 71865

      Scope and Application
      1 1   This method is applicable to drinking, surface and saline waters, sewage and industrial
           waste effluents
      1 2   The concentration range for this method is 2-20 mg/1 of iodide
      Summary of Method
      2 1   After pretreatment  to remove interferences, the sample  is analyzed for iodide by
           converting the iodide to lodate with bromine water and titrating with phenylarsme oxide
           (PAO) or sodium thiosulfate
      Sample Handling and Preservation
      3 1   Store at 4C and analyze as soon as possible
      Interferences
     A 1   Iron, manganese and organic matter  can interfere,  however, the calcium  oxide
           pretreatment removes or reduces these to insignificant concentrations
      4 2   Color interferes with the observation of indicator and bromine-water color changes  This
           interference is eliminated by the use of a pH meter instead of a pH indicator and the use
           of standardized  amounts of bromine water and sodium formate solution instead of
           observing the light yellow color changes
      Reagents
      5 1   Acetic Acid Solution (1 8)  Mix 100 ml of glacial acetic acid with 800 ml of distilled
           water
      5 2   Bromine Water   In a fume hood, add 0 2 ml bromine to 500 ml distilled water Stir with
           a magnetic stirrer and a Teflon-coated stirring bar for several hours or until the bromine
           dissolves Store in a glass-stoppered colored bottle
      5 3   Calcium Oxide (CaO)  Anhydrous, powdered
      5 4   Potassium Iodide (KI)   Crystals, ACS Reagent Grade
      5 5   Sodium Acetate  Solution (275 g/1)   Dissolve 275 g  of  sodium acetate tnhydrate
           (NaC2H3O23H2O) in distilled water Dilute to 1 liter and filter
      5 6   Sodium Formate Solution (500 g/1)   Dissolve 50 g of sodium formate (NaCHO2) in hot
           distilled water and dilute to 100 ml
      5 7   Nitrogen Gas  Cylinder
      5 8   Sulfunc Acid  Solution  (1 4)   Slowly add 200 ml of H2SO4 (sp  gr 1  84) to 800 ml of
           distilled water
      5 9   Phenylarsme Oxide (0 0375 N)  Hach Chemical Co or equivalent  Standardize  with
           0 0375 N potassium bnodate (5 15, 5 18)
Issued 1974

                                         345 1-1

-------
 5 10 Phenylarsme Oxide Working Standard (0 0075 N)   Transfer 100 ml of commercially
      available 0 0375 N phenylarsine oxide (5 9) to a 500 ml volumetric flask and dilute to the
      mark with distilled water This solution should be prepared fresh daily
 511 Commercially available starch indicators such as thyodene or equivalent may be used
 5 12 Sodium Thiosulfate, Stock Solution, 075 N   Dissolve 186 15  g (Na2S2O35H2O) m
      boiled  and  cooled distilled water and  dilute to 1 0 liter Preserve by adding  5 ml
      chloroform
 5 13 Sodium Thiosulfate Standard Titrant, 0 0375 N   Prepare by diluting 50 0 ml of stock
      solution to 1 0 liter  Preserve by adding 5 ml of chloroform Standardize with 0 0375 N
      potassium buodate (5 15,5  18)
 5.14 Sodium Thiosulfate Working  Standard  (00075  N)   Transfer 100 ml of sodium
      thiosulfate standard titrant (5 13) to a 500 ml volumetric flask and dilute to the mark
      with distilled water This solution should be prepared fresh daily
 515  Potassium Buodate Standard, 00375 N    Dissolve  4873  g  potassium buodate,
      previously dried 2 hours at 103C, in distilled water and dilute to 1 0 liter Dilute 250 ml
      to 1 0 liter for 0 0375 N buodate solution
 5.16  Starch Solution   Prepare  an emulsion of 10 g of soluble starch in a mortar or beaker
      with a small quantity of distilled water Pour this emulsion into 1 liter of boiling water,
      allow to boil a few minutes, and let settle overnight  Use  the clear supernate  This
      solution may be preserved by the addition of 5 ml per liter of chloroform and storage in a
      10C refrigerator  Commercially available, powdered starch indicators may be used in
      place of starch solution
 5.17  Potassium Fluoride (KF2H2O) ACS Reagent Grade
 518  Standardization   of 0 0375   N  Phenylarsme   Oxide  and  0 0375   N  sodium
      thiosulfate.   Dissolve approximately 2 g ( 1  0 g) KI (5 4) m 100 to 150 ml distilled
      water, add 10 ml H2SO4 solution (5 8) followed by 20 ml standard potassium buodate
      solution (5 15) Place in dark for 5 minutes, dilute to 300 ml and titrate with phenylarsine
      oxide (5 9) or sodium thiosulfate standard titrant (5 13) to a pale straw color  Add a
      small scoop of indicator (5 11) Wait until homogeneous color develops and continue the
      titration drop by  drop until the  blue color disappears  Run in duplicate  Duplicate
      determinations should agree within 0 05 ml
Procedure
61   Pretreatment
      6 1 1 Add a visible excess of CaO (5 3) to 400 ml of sample Stir or shake vigorously for
           approximately 5 minutes  Filter through  a dry, moderately retentive filter paper,
           discarding the first 75 ml
6 2   Iodide Determination
      621 Place 100 ml of pretreated sample (6 1) or a fraction thereof diluted to that volume,
          into a 150 ml beaker Add a Teflon-coated stirring bar and place on a magnetic
          sturer Insert a pH electrode and adjust the pH to approximately 7 or slightly less
          by the dropwise addition of H2SO4 solution (5 8)
      622 Transfer the sample to a 250 ml wide-mouthed conical flask Wash beaker with
          small amounts of distilled water and add washings to the flask
                                    345 1-2

-------
           NOTE   A 250  ml iodine flask  would  increase accuracy and precision by
           preventing possible loss of the iodine generated upon addition of potassium iodide
           and sulfuric acid (631)
      623 Add 15 ml sodium acetate solution (5 5) and 5 ml acetic acid solution (5 1) Mix
           well Add 40 ml bromine water solution (5 2), mix well Wait 5 minutes
      624 Add 2 ml sodium formate solution (5 6), mix well  Wait 5 minutes
      625 Purge the space above the sample with a gentle stream of nitrogen  (5 7) for
           approximately 30 seconds to remove bromine fumes
      626 If a precipitate forms (iron), add 0 5 g KF2H2O (5 17)
      6 2 7 A distilled water blank must be run with each set of samples because of iodide in
           reagents If a  blank is consistently  shown to be zero  for a particular "lot" of
           chemicals it can then be ignored
6 3   Titration
      631 Dissolve approximately 1 g potassium iodide (5 4) in sample Add 10 ml of H2SO4
           solution (5 8) and place in dark for 5 minutes
      632 Titrate with phenylarsme oxide working standard (5 10)  or sodium thiosulfate
           working standard solution (5 14) adding indicator (5 11 or 5 15) as end point is
           approached (light straw color)  Titrate to colorless solution Disregard returning
           blue color
Calculations
T /   /1\   11 nrrv
I-(mg/l) = 21,150
                                            I  ml X N \
                                            I   y - \
where
ml = the number of ml of PAO needed to titrate the sample
N = the normality of the PAO used to titrate the sample
V = the volume of sample taken (100 ml or a fraction thereof)
21,150 was calculated from the number of equivalents of iodine produced when the potassium
iodide was added and from the rearrangement of the equation to produce the value in terms of
mg/1
Precision and Accuracy
81   In a single laboratory (EMSL), using a mixed domestic and industrial waste effluent, at
     concentrations of 1 6,  4 1, 6 6, 11 6 and 21 6 mg/1 of iodide, the standard deviations
     were 023, 017,  010,  006 and  0 50 mg/1, respectively
82   In a single laboratory (EMSL), using a mixed domestic and industrial waste effluent at
     concentrations of 4 1, 6 6, 11 6 and 216 mg/1 of iodide, recoveries were 80, 97, 97 and
     92%, respectively
                                    345,1-3

-------
                                      Bibliography

1    Annual Book of ASTM Standards, Part 31 ".Water", Standard D1246-68, p 328, Method C
     (1976)
2.    Bender, D  F, "Modification of the lodimetric Titration Method for the Determination of
     Bromide and  its Application  to  Mixed  Domestic-Industrial  Waste Effluent",  Analyst
     (London) 100, p400-404 (June 1975)
                                        345-1-4

-------
                              NITROGEN, AMMONIA

                 Method  350.1 (Colorimetric, Automated Phenate)

                                                         STORET NO.  Total 00610
                                                                      Dissolved 00608

      Scope and Application
      1 1   This method covers the determination of ammonia in drinking,  surface, and  saline
           waters, domestic and industrial wastes in the range of 0 01 to 2 0 mg/1 NH3 as N This
           range is for photometric measurements made at 630-660 nm in a 15 mm or 50 mm
           tubular  flow  cell  Higher concentrations can  be determined by  sample  dilution
           Approximately 20 to 60 samples per hour can be analyzed
      Summary of Method
      2 1   Alkaline phenol and hypochlonte react with ammonia to form indophenol blue that is
           proportional to the ammonia concentration  The blue color formed is intensified with
           sodium mtroprusside
      Sample Handling and Preservation
      3 1   Preservation by addition of 2 ml cone H2SO4 per liter and refrigeration at 4C
      Interferences
      4 1   Calcium and magnesium  ions may be present  in concentration  sufficient  to  cause
           precipitation problems during analysis A 5% EDTA solution is used to prevent the
           precipitation of calcium and magnesium ions from river water and industrial waste For
           sea water a sodium potassium tartrate solution is used
      4 2   Sample turbidity and color may interfere with this method Turbidity must be removed
           by filtration prior to analysis Sample color that absorbs in the photometric range used
           will also interfere
      Apparatus
      5 1   Techmcon AutoAnalyzer Unit (AAI or AAII) consisting of
           511 Sampler
           5 1 2 Manifold (AAI) or Analytical Cartridge (AAII)
           513 Proportioning pump
           5 1 4 Heating bath with double delay coil (AAI)
           515 Colorimeter equipped with 15 mm tubular flow cell and 630-660 nm filters
           516 Recorder
           5 1 7 Digital printer for AAII (optional)
Approved for NPDES  following preliminary distillation, Method 3502
Issued 1974
Editorial revision 1978
                                        350 1-1

-------
Reagents
6 1   Distilled water Special precaution must be taken to insure that distilled water is free of
      ammonia Such water is prepared by passage of distilled water through an ion exchange
      column comprised of a mixture of both strongly acidic cation and strongly basic anion
      exchange resins The regeneration of the ion exchange column should be carried out
      according to the instruction of the manufacturer
      NOTE 1: All solutions must be made using ammonia-free water
6 2   Sulfunc acid 5N  Air scrubber solution Carefully add 139 ml of cone sulfunc acid to
      approximately 50Q ml  of ammonia-free distilled water Cool to room temperature and
      dilute to 1 liter with ammonia-free distilled water
6 3   Sodium phenolate Using a 1 liter Erlenmeyer flask, dissolve 83 g phenol  in 500 ml of
      distilled water In small increments, cautiously add  with  agitation, 32 g of NaOH
      Periodically cool flask under water faucet When cool, dilute to  1 liter with  distilled
      water
6 4   Sodium hypochlonte solution Dilute 250 ml of a bleach solution containing 5 25%
      NaOCl (such as "Clorox") to 500 ml with distilled water Available chlorine level should
      approximate 2 to 3% Since "Clorox" is a proprietary product, its formulation is subject
      to change The analyst must remain alert to  detecting any variation in this  product
      significant to its use in this procedure Due to the instability of this product, storage over
      an extended period should be avoided
65   Disodium ethylenediamme-tetraacetate (EDTA)  (5%)  Dissolve  50 g of EDTA
      (disodium salt) and approximately six pellets of NaOH m 1 liter of distilled water
      NOTE 2:  On salt water samples where EDTA solution does not prevent precipitation of
      cations, sodium potassium tartrate solution may be used to advantage It is prepared as
      follows
      6 5 1 Sodium potassium tartrate  solution  10%  NaKC4H4O64H2O  To 900 ml of
           distilled water add 100 g sodium potassium tartrate Add 2 pellets of NaOH and a
           few  boiling chips, boil gently for 45 minutes Cover, cool, and dilute to 1 liter with
           ammonia-free distilled water Adjust pH to 5 2  05 with H2SO4 After allowing to
           settle overnight in a cool place, filter to remove precipitate Then add 1/2 ml Bnj-
           35(4> (available from Techmcon Corporation) solution and store in stoppered bottle
6 6   Sodium nitroprusside  (0 05%) Dissolve 0 5 g of sodium  mtroprusside in 1 liter of
      distilled water
6 7   Stock solution Dissolve 3 819 g  of anhydrous ammonium  chloride,  NH4C1, dried at
      105C, in distilled water, and dilute to 1000 ml  1 0 ml = 1 0 mg NH3-N
6.8   Standard  Solution A Dilute 10 0 ml  of stock solution (6 7) to 1000 ml with distilled
      water 1 0 ml = 0 01 mg NH3-N
6 9   Standard  solution B Dilute 10 0 ml of standard solution  A (6 8) to 100 0 ml  with
      distilled water  1 0 ml = 0 001 mg NH3-N
                                    350 1-2

-------
 6 10  Using standard solutions A and B, prepare the following standards in 100 ml volumetric
      flasks (prepare fresh daily)

               NH3-N.  mg/1                        ml Standard Solution/100 ml

                                                             Solution  B

                  001                                           10
                  002                                           20
                  005                                           50
                  010                                          100

                                                             Solution  A

                  020                                           20
                  050                                           50
                  080                                           80
                  1 00                                          10 0
                  1 50                                          15 0
                  2 00                                          20 0

      NOTE  3: When saline water samples are analyzed, Substitute Ocean Water (SOW)
      should  be used for  preparing the above  standards used for the calibration curve,
      otherwise, distilled water is used If SOW is used, subtract its blank background response
      from the standards before preparing the standard curve

                          Substitute Ocean Water (SOW)

    NaCl        24 53 g/1                        NaHCO3  0 20 g/1
    MgCl2       5 20 g/1                        KBr     0 10 g/1
    Na2SO4      409 g/1                        H3BO3    003 g/1
    CaCl2       1 16 g/1                        SrCl2     0 03 g/1
    KC1         0 70 g/1                        NaF     0 003 g/1

Procedure
7 1    Since the intensity of the color used to quantify the concentration is pH dependent, the
      acid concentration of the wash water and the standard ammonia solutions should
      approximate that of the samples  For example, if the samples have been preserved with 2
      ml cone H2SO4/liter, the wash water and standards should also contain 2 ml cone
      H2SO4/hter
7 2    For a working range of 0 01 to 2 00 mg NH3-N/1 (AAI), set up the manifold as shown in
      Figure 1 For a working range of 01 to 1 0 mg NH3-N/1 (AAII), set up the manifold as
      shown in Figure 2 Higher concentrations may be accommodated by sample dilution
7 3    Allow both colorimeter and recorder to warm up for 30 minutes Obtain a stable baseline
      with all reagents, feeding distilled water through sample line
7 4    For the  AAI system, sample at a rate  of 20/hr, 1 1  For the AAII use a 60/hr 6 1 cam
      with a common wash
                                    350 1-3

-------
     7 5  Arrange ammonia standards in sampler in order of decreasing concentration of nitrogen
          Complete loading of sampler tray with unknown samples
     7 6  Switch sample line from distilled water to sampler and begin analysis
8    Calculations
     8 1  Prepare  appropriate  standard curve derived from processing  ammonia  standards
          through manifold Compute concentration of samples by comparing sample peak heights
          with standard curve
9    Precision and Accuracy
                                                                             
     91  In a single laboratory (EMSL), using surface water samples at concentrations of 1 41,
          0 77,0 59 and 0 43 mg NH3-N/1, the standard deviation was 0 005
     9.2  In a single laboratory (EMSL), using surface water samples at concentrations of 0 16 and
          1 44 mg NH3-N/1, recoveries were 107% and 99%, respectively

                                      Bibliography

1.    Killer, A , and Van Slyke, D , "Determination of Ammonia in Blood", J Biol  Chem 102, p
     499 (1933)
2,    O'Connor, B, Dobbs,  R, Vilhers, B , and Dean, R, "Laboratory Distillation of Municipal
     Waste Effluents", JWPCF 39, R 25 (1967)
3.    Fiore, J., and  O'Brien, J E, "Ammonia Determination by Automatic Analysis", Wastes
     Engineering 33, p 352 (1962)
4    A wetting  agent recommended  and supplied by  the  Techmcon Corporation for use in
     AutoAnalyzers
5.    ASTM "Manual on Industrial Water and Industrial Waste Water", 2nd Ed , 1966 printing, p
     418
6.    Booth, R L, and Lobnng, L B ,  "Evaluation of the AutoAnalyzer II A Progress Report" in
     Advances m Automated Analysis  1972 Techmcon International Congress, Vol 8,  p 7-10,
     Mediad Incorporated, Tarrytown, N Y , (1973)
7    Standard Methods  for the Examination of Water and Wastewater,  14th  Edition, p 616,
     Method 604 (1975)
                                        350 1-4

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                             NITROGEN, AMMONIA

            Method 350.2 (Colorimetric; Titrimetric;  Potentiometric  -
                               Distillation Procedure)

                                                         STORET  NO.  Total 00610
                                                                      Dissolved 00608

     Scope and Application
     1 1  This distillation method covers the determination of ammonia-nitrogen exclusive of total
          Kjeldahl nitrogen, in drinking, surface and saline waters, domestic and industrial wastes
          It is the method of choice where economics and sample load do not warrant the use of
          automated equipment
     1 2  The method covers the range from about 0 05 to 1 0 mg NH3-N/1 for the colonmetnc
          procedure, from 1 0 to 25 mg/1 for the titnmetric procedure, and from 0 05 to 1400
          mg/1 for the electrode method
     1 3  This method is described for macro glassware,  however, micro distillation equipment
          may also be used
     Summary of Method
     2 1  The sample is buffered at a pH of 9 5 with a borate buffer in order to decrease hydrolysis
          of cyanates and organic nitrogen compounds, and is then distilled into a solution of bone
          acid The ammonia in the distillate can be determined colonmetncally by nesslenzation,
          titnmetncally with standard sulfunc acid with the use of a  mixed indicator,  or
          potentiometncally  by the  ammonia electrode  The  choice  between the  first two
          procedures depends on the concentration of the ammonia
     Sample Handling and Preservation
     3 1  Samples may be preserved with 2 ml of cone  H2SO4 per liter and stored at 4C
     Interferences
     41  A number of aromatic and aliphatic amines, as well as other compounds, both organic
          and inorganic,  will cause turbidity upon the addition of Nessler reagent,  so direct
          nesslenzation (i e , without distillation), has been discarded as an official method
     4 2  Cyanate, which may be encountered in certain industrial effluents, will hydrolyze to
          some extent even at the pH of 9 5 at which distillation is carried out Volatile alkaline
          compounds, such as certain ketones, aldehydes, and alcohols, may cause an off-color
          upon nesslenzation in the distillation method Some of these, such as formaldehyde, may
          be eliminated by boiling off at a low pH (approximately 2 to 3) prior to distillation and
          nesslenzation
     4 3  Residual chlorine must also be removed by pretreatment of the  sample with sodium
          thiosulfate before distillation
Approved for NPDES
Issued 1971
Editorial revision 1974

                                         350 2-1

-------
Apparatus
5.1   An all-glass distilling apparatus with an 800-1000 ml flask
5 2   Spectrophotometer or filter photometer for use at 425 nm and providing a light path of 1
      cm or more
5 3   Nessler tubes Matched Nessler tubes (APHA Standard) about 300 mm long, 17 mm
      inside diameter, and marked at 225 mm 15 mm inside measurement from bottom
5.4   Erlenmeyer flasks The distillate is collected  m 500 ml glass-stoppered flasks  These
      flasks should be marked at the 350 and the 500 ml volumes With such marking, it is not
      necessary to transfer the distillate to volumetric flasks
Reagents
6 1   Distilled water should be free of ammonia  Such water is best prepared by passage
      through an ion exchange column containing  a strongly acidic cation exchange resin
      mixed with a strongly basic amon exchange resin Regeneration of the column should be
      earned out according to the manufacturer's instructions
      NOTE 1: All solutions must be made with ammonia-free water
6 2   Ammonium chloride, stock solution 1 0 ml = 1 0 mg NH3-N  Dissolve 3 819 g NH4C1
      m distilled water and bring to volume in a 1 liter volumetric flask
6.3   Ammonium chloride, standard solution 1 0 ml = 0 01 mg  Dilute  10 0 ml of stock
      solution (6 2) to 1 liter m a volumetric flask
6 4   Boric acid solution (20 g/1) Dissolve 20 g H3BO3 m distilled water and dilute to 1 liter
6 5   Mixed indicator Mix 2 volumes of 02% methyl red in 95% ethyl alcohol with 1 volume
      of 02% methylene blue in 95% ethyl alcohol  This solution should be prepared fresh
      every 30 days
      NOTE 2: Specially denatured ethyl alcohol conforming to Formula 3 A or 30 of the U S
      Bureau of Internal Revenue may be substituted for 95% ethanol
6 6   Nessler reagent Dissolve 100 g of mercuric iodide and 70 g of potassium iodide in a small
      amount of water Add this mixture slowly, with stirring, to a cooled solution of 160 g of
      NaOH in 500 ml of water Dilute the mixture to 1 liter If this reagent is stored m a Pyrex
      bottle out of direct sunlight, it will remain stable for a period of up to 1 year
      NOTE 3: This reagent should give the characteristic color with ammonia within 10
      minutes after addition, and should  not produce a precipitate with small amounts of
      ammonia (0 04 mg in a 50 ml volume)
6 7   Borate buffer Add 88 ml of 0 1 N NaOH  solution to 500 ml of 0 025 M sodium
      tetraborate solution (5 0 g anhydrous Na2B4O7 or 9 5 g Na2B4O710H2O  per liter) and
      dilute to 1 liter
6 8   Sulfunc acid, standard solution (0 02 N, 1 ml  =  0 28  mg NH3-N)   Prepare a stock
      solution of approximately 0 1  N acid by diluting 3 ml of cone  H2SO4 (sp  gr 1 84) to 1
      liter with CO2-free distilled water Dilute 200 ml of this solution to 1 liter with CO2-free
      distilled water
      NOTE  4: An alternate  and perhaps preferable  method  is  to  standardize  the
      approximately 0 1 N H2SO4 solution against a 0 100 N Na2CO3 solution  By proper
      dilution the 0 02 N acid can then be prepared
                                    350 2-2

-------
     6 8 1  Standardize the approximately 0 02 N acid against 0 0200 N Na2CO3 solution
           This last solution is prepared by dissolving 1 060 g anhydrous Na2CO3, oven-dried
           at 140C, and diluting to 1000 ml with CO2-free distilled water
6 9  Sodium hydroxide, 1 N Dissolve 40 g NaOH in ammonia-free water and dilute to 1 liter
6 10 Dechlormating reagents A number of dechlonnatmg reagents may be used to remove
     residual chlorine prior to distillation  These include
     a     Sodium thiosulfate (1/70 N)  Dissolve 3 5 g Na2S2O35H2O in distilled water and
           dilute to 1 liter One ml of this solution will remove 1 mg/1 of residual chlorine in
           500 ml of sample
     b     Sodium arsenite (1/70 N)  Dissolve 1 0 g NaAsO2 in distilled water and dilute to 1
           liter
Procedure
7 1  Preparation of equipment Add 500 ml of distilled water to an 800 ml Kjeldahl flask The
     addition of boiling chips which have been previously treated with dilute NaOH will
     prevent bumping  Steam out the distillation apparatus until the distillate shows no trace
     of ammonia with Nessler reagent
7 2  Sample  preparation  Remove the  residual  chlorine in  the sample  by  adding
     dechlonnatmg  agent equivalent to the chlorine residual  To 400 ml of sample add 1 N
     NaOH (6 9), until the pH is 9 5, checking the pH during  addition with a pH meter or by
     use of a short range pH paper
7 3  Distillation Transfer the sample, the pH of which has been adjusted to 9 5, to an 800 ml
     Kjeldahl flask and add 25 ml of the borate buffer (6 7) Distill  300 ml at the rate of 6-10
     ml/mm into 50 ml of 2% boric acid (6 4) contained in a 500 ml Erlenmeyer flask
     NOTE 5: The condenser tip or an extension of the condenser tip must extend below the
     level of the bone acid solution
     Dilute the distillate to 500 ml with distilled water and nesslenze an aliquot to obtain an
     approximate value of the ammonia-nitrogen concentration  For concentrations above 1
     mg/1 the ammonia should be determined titrimetrically  For  concentrations below this
     value it is determined colorimetrically The electrode method may also be used
7 4  Determination of ammonia in distillate Determine the ammonia content of the distillate
     titrimetrically,  colonmetrically or potentiometrically as described below
     741  Titrimetric determination Add 3 drops of the mixed indicator to the distillate and
           titrate the ammonia with the 0 02 N H2SO4, matching the end point against a blank
           containing the same volume of distilled water and H3BO3 solution
                                     350 2-3

-------
      742 Colonmetnc determination Prepare a series of Nessler tube standards as follows

               ml of Standard
          10 ml  = 001 mg NH3-N                       mg NH3-N/50 0 ml

                   00                                            00
                   05                                         0 005
                   10                                           001
                   20                                           002
                   30                                           003
                   40                                           004
                   50                                           005
                   80                                           008
                  100                                           010

           Dilute each tube to 50 ml with distilled water, add 2 0 ml of Nessler reagent (6 6)
           and mix After 20 minutes read the absorbance at 425 nm against the blank  From
           the  values obtained plot absorbance vs  mg NH3-N  for the standard curve
           Determine the ammonia in the distillate by nesslenzing 50 ml or an aliquot diluted
           to 50 ml and reading the  absorbance  at 425  nm as  described above for the
           standards Ammonia-nitrogen content is read from the standard curve
      743 Potentiometnc determination Consult the method entitled Nitrogen, Ammonia
           Selective Ion Electrode Method (Method 350 3) in this manual
75   It is not imperative that all standards be distilled in the same manner as the samples It is
      recommended that at least two standards (a high and low) be distilled and  compared to
      similar values on the curve to insure that the distillation technique is reliable  If distilled
      standards do not agree with undistilled standards the operator should find the cause of
      the apparent error before proceeding
Calculations
8 1   Titnmetnc

                         mg/1 NH, - N = Ax 028X1,000
                                                 O

      where
      A = ml 0 02 N H2SO4 used
      S = ml sample
8 2   Spectrophotometnc

                         mg/1 NH3 -  N = A xj'000  x  .B.

     where
     A = mg NH3-N read from standard curve
     B = ml total distillate collected, including bone acid and dilution
     C = ml distillate taken for nesslenzation
     D = ml of onginal sample taken
                                    350 2-4

-------
     8 3   Potentiometric
                                 mg/1 NH3 - N =
                       500
                        D
xA
          where
          A = mg NHy-N/1 from electrode method standard curve
          D = ml of original sample taken
     Precision and Accuracy
     9 1   Twenty-four analysts in sixteen laboratories analyzed natural water samples containing
          exact increments of an ammonium salt, with the following results
      Increment as
   Nitrogen, Ammonia
       mg N/hter

          021
          026
          171
          192
   Precision as
Standard Deviation
    mgN/hter

      0122
      0070
      0244
      0279
                                                                 Accuracy as
  Bias,
  -554
 -18 12
 +046
  -201
   Bias,
mg N/hter

   -001
   -005
   +001
   -004
(FWPCA Method Study 2, Nutrient Analyses)
                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 410,
     Method 41 8 A and 418B (1975)
2    Annual Book of ASTM Standards, Part 31, "Water", Standard D 1426-74, Method A, p 237
     (1976)
                                         350 2-5

-------
                              NITROGEN, AMMONIA

              Method 350.3 (Potentiometric, Ion Selective Electrode)

                                                          STORET NO. Total 00610
                                                                      Dissolved 00608

      Scope and Application
      1 1   This method is applicable to the measurement of ammonia-nitrogen in drinking, surface
           and saline waters, domestic and industrial wastes
      1 2   This method covers the range from 0 03 to 1400 mg NH3-N/1 Color and turbidity have
           no effect on the measurements, thus, distillation may not be necessary
      Summary of Method
      2 1   The ammonia is determined potentiometncally using an ion selective ammonia electrode
           and a pH meter having an expanded millivolt scale or a specific ion meter
      2 2   The ammonia electrode uses a hydrophobic gas-permeable membrane to separate the
           sample solution from an ammonium chloride internal solution Ammonia in the sample
           diffuses through the membrane and alters the pH of the internal solution, which is sensed
           by a pH electrode The constant level of chlonde in the internal solution is sensed  by a
           chloride selective ion electrode which acts as the reference electrode
      Sample Handling and Preservation
      3 1   Samples may be preserved with 2 ml of cone H2SO4 per liter and stored at 4C
      Interferences
      4 1   Volatile amines act as a positive interference
      4 2   Mercury interferes by forming a strong complex with ammonia Thus the samples cannot
           be preserved with mercuric chlonde
      Apparatus
      5 1   Electrometer (pH meter) with expanded mV scale or a specific ion meter
      5 2   Ammonia selective electrode, such as Orion Model 95-10 or EIL Model 8002-2
      5 3   Magnetic stirrer, thermally insulated, and Teflon-coated stirring bar
      Reagents
      6 1   Distilled water Special precautions must be taken to insure that the distilled water is free
           of ammonia This is accomplished by passing distilled water through an ion exchange
           column containing a strongly acidic cation exchange resin mixed with a strongly basic
           anion exchange resin
      6 2   Sodium hydroxide, ION Dissolve 400 g of sodium hydroxide in 800 ml of distilled water
           Cool and dilute to 1 liter with distilled water (6 1)
      6 3   Ammonium chlonde, stock solution  1 0 ml =  1 0 mg NH3-N Dissolve 3 819 g NH4C1
           in water and bnng to volume in a 1 liter volumetric flask using distilled water (6 1)
Issued 1974
Approved for NPDES following preliminary distillation (Method 350 2)

                                         350 3-1

-------
      6 4   Ammonium chloride, standard solution  1 0 ml = 0 01 mg NH3-N Dilute 10 0 ml of the
            stock solution (6 3) to 1 liter with distilled water (6 1) in a volumetric flask
            NOTE 1: When analyzing saline waters, standards  must be made up in synthetic ocean
            water (SOW), found in Nitrogen, Ammonia Colonmetnc, Automated Phenate Method
            (350 1)
 7    Procedure
      7 1   Preparation  of standards  Prepare  a series of standard  solutions  covering the
            concentration range of the samples by diluting either the stock or standard solutions of
            ammonium chloride
      72   Calibration of electrometer  Place 100 ml of each standard solution in clean  150 ml
            beakers Immerse electrode into standard of lowest  concentration and add 1 ml of ION
            sodium hydroxide solution while mixing Keep electrode in the solution until a stable
            reading is obtained
            NOTE 2: The pH of the solution after the addition of NaOH must be above 11
            Caution  Sodium hydroxide must not  be  added  prior  to electrode immersion, for
           ammonia may be lost from a basic solution
      7 3  Repeat this procedure with the remaining standards, going from lowest to highest
           concentration Using semiloganthmic graph paper, plot the concentration of ammonia in
           mg NH3-N/1 on the log axis vs the electrode potential developed in the standard on the
           linear axis, starting with the lowest concentration at the bottom of the scale
      7.4  Calibration of a specific ion meter Follow  the directions  of the manufacturer  for the
           operation of the instrument
      7 5  Sample measurement  Follow the procedure in (7 2) for 100 ml of sample in  150 ml
           beakers Record the  stabilized potential of each unknown sample  and convert the
           potential reading to the ammonia concentration using the  standard curve If a specific
           ion meter is used, read the ammonia level directly in mg NH3-N/1
8.    Precision and Accuracy
      81   In a single laboratory (EMSL), using surface water samples at concentrations of 1 00,
           0 77, 0 19, and 0 13 mg NH3-N/1, standard deviations were   0 038,  0 017,  0 007,
           and 0 003, respectively
      82   In a single laboratory (EMSL), using surface water samples at concentrations of 0 19 and
           0 13 mg NH3-N/1, recoveries were 96% and 91%, respectively

                                       Bibliography

1.    Booth, R L , and Thomas, R F, "Selective Electrode Determination of Ammonia in Water
      and Wastes", Envir  Sci  Technology, 7, p 523-526 (1973)
2.    Banwart, W L , Bremner, J M, and Tabatabai, M A, "Determination of Ammonium in Soil
      Extracts and Water Samples by  an Ammonia Electrode", Comm Soil Sci Plant ,3,p 449
      (1952)
3.    Midgley, D , and Torrance, K , "The Determination of Ammonia in Condensed Steam and
      Boiler Feed-Water with a Potentiometnc Ammonia Probe", Analyst, 97 p 626-633 (1972)
                                        350 3-2

-------
                       NITROGEN, KJELDAHL, TOTAL

                Method  351.1  (Colorimetric,  Automated Phenate)

                                                               STORET NO.  00625

1    Scope and Application
     1 1   This automated method may be used to determine Kjeldahl nitrogen in surface and
          saline waters The applicable range is 0 05 to 2 0 mg N/l Approximately 20 samples per
          hour can be analyzed
2    Summary of Method
     2 1   The sample is automatically digested with a sulfunc acid solution containing potassium
          sulfate and mercuric sulfate as a catalyst to convert organic nitrogen to ammonium
          sulfate The solution is then automatically neutralized with sodium hydroxide solution
          and treated with alkaline  phenol  reagent and sodium  hypochlonte reagent  This
          treatment forms  a blue color designated as indophenol Sodium nitroprusside, which
          increases  the intensity of  the color,  is added to  obtain  necessary sensitivity for
          measurement of low level nitrogen
3    Definitions
     3 1   Total Kjeldahl nitrogen is defined as the sum of free-ammonia and of organic nitrogen
          compounds which are converted to (NH4)2SO4 under the conditions of digestion which
          are specified below
     3 2   Organic Kjeldahl nitrogen is defined as the difference obtained by subtracting the free-
          ammonia value from the total Kjeldahl nitrogen value Also, organic Kjeldahl nitrogen
          may be determined directly by removal of ammonia before digestion
4    Sample Handling and Preservation
     4,1   Samples may be preserved by addition of 2 ml of cone  H2SO4 per liter and refrigeration
          at 4C Even when preserved in this manner, conversion of organic nitrogen to ammonia
          may occur Therefore, samples should be analyzed as soon as possible
5    Interferences
     5 1   Iron and chromium ions tend to catalyze while copper ions tend to inhibit the indophenol
          color reaction
6    Apparatus
     6 1   Techmcon AutoAnalyzer consisting of
           611  Sampler II, equipped with continuous mixer
           612  Two proportioning pumps
           6 1 3  Manifold I
           6 1 4  Manifold II
           615  Continuous digester
           616  Planetary pump

Approved for NPDES, pending approval for Section 304(h), CWA
Issued 1971
Editorial revision 1974 and 1978

                                        351 1-1

-------
           617 Five-gallon Carboy fume-trap
           6 1 8 80C Heating bath
           619 Colorimeter equipped with 50 mm tubular flow cell and 630 nm filters
           6 1 10 Recorder equipped with range expander
           6111 Vacuum pump
7.   Reagents
     7 1   Distilled water  Special precaution must be taken to insure that distilled water is free of
           ammonia Such water is prepared by passage of distilled water through an ion exchange
           column comprised of a mixture of both strongly acidic cation and strongly basic anion
           exchange resins  Furthermore, since organic contamination may interfere  with this
           analysis, use of the resin Dowex XE-75 or equivalent which also tends to remove organic
           impurities is advised The regeneration of the ion exchange column should be carried out
           according to the instruction of the manufacturer
           NOTE 1: All solutions must be made using ammonia-free water
     7 2   Sulfunc acid As it readily absorbs ammonia, special precaution must also be taken with
           respect to its use Do not store bottles reserved for this determination in areas of potential
           ammonia contamination
     7 3   EDTA (2% solution) Dissolve 20 g disodium ethylenediamme tetraacetate m 1 liter of
           distilled water Adjust pH to 10 5-11 with NaOH (7 4)
     7 4   Sodium hydroxide (30% solution) Dissolve 300 g NaOH in 1 liter of distilled water
           NOTE 2: The 30% sodium hydroxide should be sufficient to neutralize the digestate In
           rare cases it may be necessary to increase the concentration of sodium hydroxide in this
           solution  to insure neutralization of the digested sample in the manifold at the water
          jacketed mixing coil
     7 5   Sodium mtroprusside, (0 05% solution) Dissolve 0 5 g Na2Fe(CN)5NO2H2O in 1 liter
           distilled water
     7.6   Alkaline phenol reagent Pour 550 ml liquid phenol (88-90%) slowly with mixing into 1
           liter of 40% (400 g per liter) NaOH Cool and dilute to 2 liters with distilled water
     7 7   Sodium hypochlonte (1% solution) Dilute commercial "Clorox"-200 ml to 1  liter with
           distilled  water  Available chlorine level should  be approximately 1%  Due  to the
           instability of this product, storage over an extended period should be avoided
     7 8   Digestant mixture Place 2 g red HgO in a 2 liter container  Slowly add, with stirring, 300
           ml of acid water (100 ml H2SO4 + 200 ml H2O) and stir until cool Add 100 ml 10% (10
           g per 100 ml) K2SO4  Dilute to 2 liters with cone sulfunc acid (approximately 500 ml at a
           time,  allowing time  for cooling)  Allow 4  hours  for the precipitate to settle or  filter
           through glass fiber filter
     7 9   Stock solution  Dissolve 4 7193  gof pre-dried (1 hour at 105C) ammonium  sulfate in
           distilled water and dilute to 1 0 liter in a volumetric flask 1  0 ml = 10 mg N
     7 10  Standard solution  Dilute 10 0 ml of stock solution (7 9) to 1000 ml 1 0 ml = 0  01 mg N
     711  Using the standard solution (7 10), prepare the following standards in 100 ml volumetric
          flasks
                                         351 1-2

-------
              Cone  mg N/l                         ml Standard Solution/100 ml

                 000                                            00
                 005                                            05
                 010                                            10
                 020                                            20
                 040                                            40
                 060                                            60
                 080                                            80
                 1 00                                           10 0
                 1 50                                           150
                 2 00                                           20 0

Procedure
8 1   Set up manifolds as shown in Figures 1,2, and 3
     8 1 1  In the operation of manifold No  1, the control of four key factors is required to
           enable manifold No  2 to receive the mandatory representative feed First, the
           digestant flowing into the pulse chamber (PC-1) must be bubble free, otherwise, air
           will accumulate in A-7, thus altering the ratio of sample to digestant in digester
           Second, in maintaining even flow from the digestor helix, the peristaltic pump must
           be adjusted to cope with differences in density of the digestate and the wash water
           Third, the sample pick-up rate from the helix must be precisely adjusted to insure
           that the entire sample is aspirated into the mixing  chamber  And finally, the
           contents of the "Mixing Chamber" must be kept homogeneous by the proper
           adjustment of the air bubbling rate
      8  1 2 In the operation of manifold  No 2, it is important m the neutralization of the
           digested sample to adjust the concentration of the NaOH so that the waste from the
           C-3 debubbler is slightly acid to Hydnon B paper
      8  1 3 The digestor temperature is 390C for the first stage and 360C for the second and
           third stages
 8 2   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
      reagents, feeding distilled water through the sample line  Adjust dark current and
      operative opening on colorimeter to obtain stable baseline
 8 3   Set sampling rate of Sampler II at 20 samples per hour, using a sample to wash ratio of 1
      to 2 (1 minute sample, 2 minute wash)
 8 4   Arrange various standards in sampler  cups in order of increasing  concentration
      Complete loading of sampler tray with unknown samples
 8 5   Switch sample line from distilled water to sampler and begin analysis
 Calculation
 9 1   Prepare standard  curve by plotting  peak heights  of processed standards against
      concentration values Compute concentration of samples  by comparing sample peak
      heights with standard curve
 9 2   Any sample that has a computed concentration that is less than 10% of the sample run
      immediately prior to it must be rerun
                                     351 1-3

-------
 10
1.
 Precision and Accuracy
 10 1  Six laboratories analyzed four natural water samples containing exact increments of
      organic nitrogen compounds, with the following results
      Increment as
    Kjeldahl-Nitrogen
       mg N/liter

          1 89
          2 18
          509
          581
                         Precision as
                     Standard Deviation
                    Kjeldahl-N mgN/hter

                            054
                            061
                            125
                            185
Bias,
-246
-283
-238
-219
         Accuracy as
   Bias,
mg N/hter

   -046
   -062
   -121
   -127
                                      Bibliography
Kammerer, P A , Rodel, M G, Hughes, R A , and Lee, G F , "Low Level Kjeldahl Nitrogen
Determination on the Techmcon Auto Analyzer"  Environmental Science and Technology, 1,
340(1967)                                                                       -
McDamel, W  H , Hemphill, R N, Donaldson, W T, "Automatic Determination of Total
Kjeldahl Nitrogen in Estuanne Waters" Presented at Techmcon Symposium on Automation
m Analytical Chemistry, New York, October 3,1967
B O'Connor,  Dobbs, Vilhers, and  Dean, "Laboratory Distillation of Municipal  Waste
Effluents" JWPCF39.R25,1967
                                       351 1-4

-------
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                                351 1-6

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          351 1-7

-------
                       NITROGEN,  KJELDAHL, TOTAL

      Method 351.2  (Colorimetric, Semi-Automated Block Digester, AAII)

                                                               STORET NO. 00625

1    Scope and Application
     1 1   This method covers the determination of total Kjeldahl nitrogen in drinking and surface
          waters, domestic and industrial wastes The procedure converts nitrogen components of
          biological origin such as ammo acids, proteins and peptides to ammonia, but may not
          convert the mtrogeneous compounds of some industrial wastes such as amines, mtro
          compounds,  hydrazones, oximes, semicarbazones and some refractory tertiary amines
          The applicable range of this method is 0 1 to 20 mg/1 TKN The range may be extended
          with sample dilution
2    Summary of Method
     2 1   The sample is heated in the presence of sulfunc acid, K2SO4 and HgSO4 for two and one
          half hours The residue is cooled, diluted to 25 ml and placed on the AutoAnalyzer for
          ammonia determination   This  digested sample may also be used  for  phosphorus
          determination
3    Definitions
     3 1   Total  Kjeldahl nitrogen is defined as the sum of free-ammonia  and organic nitrogen
          compounds which are converted to ammonium sulfate (NH4)2SO4, under the conditions
          of digestion described below
     3 2   Organic Kjeldahl nitrogen is defined as the difference obtained by subtracting the free-
          ammonia value (Method 350 2,  Nitrogen,  Ammonia, this manual) from  the total
          Kjeldahl nitrogen value
4    Sample Handling and Preservation
     4 1   Samples may be preserved by addition of 2 ml of cone H2SO4 per liter and stored at 4C
          Even when preserved in this manner, conversion of organic nitrogen to ammonia may
          occur Therefore, samples should be analyzed as soon as possible
5    Apparatus
     5 1   Block Digestor-40
     5 2   Techmcon Manifold for Ammonia (Figure 1)
     5 3   Chemware TFE (Teflon boiling stones), Markson Science, Inc, Box 767, Delmar, CA
          92014)
6    Reagents
     6 1   Mercuric Sulfate  Dissolve 8 g red mercuric oxide (HgO) in 50 ml of 1 4 sulfunc acid (10
          ml cone H2SO4 40 ml distilled water) and dilute to 100 ml with distilled water
     6 2   Digestion Solution (Sulfunc acid-mercunc sulfate-potassium sulfate solution) Dissolve
           133 g of K2SO4 in 700 ml of distilled water  and 200 ml of cone H2SO4 Add 25  ml of
          mercunc sulfate solution and dilute to 1 liter

Pending approval for NPDES
Issued 1978

                                        351 2-1

-------
      6.3   Sulfunc Acid Solution (4%) Add 40 ml of cone sulfunc acid to 800 ml of ammonia free
           distilled water, cool and dilute to 1 liter
      6 4   Stock Sodium Hydroxide (20%) Dissolve 200 g of sodium hydroxide in 900 ml of
           ammonia-free distilled water and dilute to 1 liter
      6 5   Stock Sodium Potassium Tartrate Solution (20%) Dissolve 200 g sodium potassium
           tartrate in about 800 ml of ammonia-free distilled water and dilute to 1 liter
      6 6   Stock Buffer Solution Dissolve 134 0 g of sodium phosphate, dibasic (Na2HPO4) in
           about 800 ml of ammonia free water Add 20 g of sodium hydroxide and dilute to 1 liter
      6.7   Working Buffer Solution Combine the reagents in the stated order, add 250 ml of stock
           sodium potassium tartrate solution (6 5) to 200 ml of stock buffer solution (6 6) and mix
           Add xx ml sodium hydroxide  solution  (6 4) and dilute to 1 liter See concentration
           ranges, Table I, for composition of working buffer
      6.8   Sodium Sahcylate/Sodium Nitroprusside Solution Dissolve 150 g of sodium sahcylate
           and 0 3 g of sodium nitroprusside in about 600 ml of ammonia free water and dilute to 1
           liter.
      6 9   Sodium Hypochlonte Solution  Dilute 6 0 ml sodium hypochlonte solution (clorox) to
           100 ml with ammonia free distilled water
      6 10  Ammonium chloride, stock solution Dissolve 3 819 g NH4C1 m distilled water and bring
           to volume in a 1 liter volumetric flask 1 ml= 1 0 mg NH3-N
7.    Procedure
      Digestion
      71   To 20 or 25 ml of sample, add  5 ml of digestion solution (6 2) and mix (use a vortex
           mixer)
      7 2   Add (4-8) Teflon boiling stones (5 3) Too many boiling chips will cause the sample to
           boil over
      7 3   With Block Digester in manual mode set low and high temperature at 160C and preheat
           unit to 160C Place tubes in digester and switch to automatic mode Set low temperature
           tuner for 1 hour Reset high temperature to 380C and set timer for 21/2 hours
      7 4   Cool sample and dilute to 25 ml with ammonia free water
      Colonmetnc Analysis
      7.5   Check the level of all reagent containers to ensure an adequate supply
      7 6   Excluding the salicylate line, place all reagent lines in their respective containers, connect
           the sample probe to the Sampler IV and start the proportioning pump
     7 7   Flush the Sampler IV wash receptacle with about 25 ml of 4 0% sulfuric acid (6 3)
     7 8   When reagents have been pumping for at least five minutes, place the sahcylate line in its
           respective container and allow the system to equilibrate  If a precipitate forms after the
           addition of sahcylate, the pH is too low Immediately stop the proportioning pump and
          flush the coils with water using a  syringe Before restarting the system, check  the
          concentration of the sulfunc acid solutions and/or the working buffer solution
                                         351 2-2

-------








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      79  To prevent precipitation of sodium sahcylate in the waste tray, which can clog the tray
           outlet, keep the nitrogen fiowcell pump tube and the nitrogen Colorimeter "To Waste"
           tube separate from all other lines or keep tap water flowing in the waste tray
      7 10 After a stable baseline has been obtained start the Sampler
 8    Calculations
      8 1   Prepare standard curve by  plotting  peak heights  of processed  standards against
           concentration values Compute concentrations by comparing sample peak heights with
           standard curve
 9    Precision and Accuracy
      91   In a single laboratory (EMSL), using sewage samples of concentrations of 1 2, 2 6, and
           1 7 mg N/l, the precision was  0 07, 0 03 and 0 15, respectively
      9.2   In a single laboratory (EMSL), using sewage samples of concentrations of 4 7 and 8 74
           mg N/l, the recoveries were 99 and 99%, respectively
                                      i     '     i *                 j  '
                                      i                *       i    
                                      Bibliography

 1     McDamel, W H, Hemphill, R N and Donaldson, W T, "Automatic Determination of Total
      Kjeldahl Nitrogen in Estuarme Water", Techmcon Symposia, pp 362-367, Vol 1,1967
2     Gales, M E , and Booth, R L, "Evaluation of Organic Nitrogen Methods", EPA Office of
      Research and Monitoring, June, 1972
3     Gales, ME  and  Booth,  RL, "Simultaneous  and Automated Determination of Total
      Phosphorus  and Total  Kjeldahl Nitrogen", Methods Development and Quality Assurance
      Research Laboratory, May, 1974
4.   Techmcon "Total Kjeldahl Nitrogen and Total Phosphorus BD-40 Digestion Procedure for
     Water", August, 1974
5    Gales, ME,  and  Booth, RL, "Evaluation  of the Block Digestion System  for the
     Measurement of Total Kjeldahl Nitrogen and  Total Phosphorus",  EPA-600/4-78-015,
     Environmental Monitoring and Support Laboratory, Cinncmnati, Ohio
                                        351 2-4

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                                  351 2-5

-------
                        NITROGEN, KJELDAHL, TOTAL

             Method 351.3 (Colorimetric; Titrimetric;  Potentiometric)

                                                                STORET  NO. 00625

1    Scope and Application
     1 1  This method covers the determination of total Kjeldahl nitrogen in drinking, surface and
          saline  waters,  domestic  and  industrial  wastes  The procedure converts nitrogen
          components of biological origin such as ammo acids, proteins and peptides to ammonia,
          but may not convert  the nitrogenous  compounds of some industrial wastes such as
          amines, mtro  compounds, hydrazones, oximes, semicarbazones and some refractory
          tertiary amines
     1 2  Three  alternatives are listed for the determination of ammonia after distillation  the
          titrimetnc  method which is applicable to concentrations above 1  mg N/liter,  the
          Nesslenzation method which is applicable to concentrations below 1 mg N/liter, and the
          potentiometnc method applicable to the range 0 05 to 1400 mg/1
     1 3  This method is described for macro and micro glassware systems
2    Definitions
     2 1  Total Kjeldahl nitrogen is defined as the  sum of free-ammonia and organic nitrogen
          compounds which are  converted to ammonium sulfate (NH4)2SO4, under the conditions
          of digestion described below
     2 2  Organic Kjeldahl nitrogen is defined as the difference obtained by subtracting the free-
          ammonia value (Method 350 2,  Nitrogen, Ammonia, this  manual) from the total
          Kjeldahl nitrogen value This may be determined directly by removal of ammonia before
          digestion
3    Summary of Method
     3 1  The sample is heated in the presence  of cone  sulfunc acid, K2SO4 and HgSO4 and
          evaporated until SO3  fumes are obtained  and the solution becomes  colorless or pale
          yellow The residue is cooled, diluted, and is treated and made alkaline with a hydroxide-
          thiosulfate solution The ammonia is distilled and  determined after distillation by
          Nesslenzation, titration or potentiometry
4    Sample Handling and Preservation
     4 1  Samples may be preserved by addition of 2 ml of cone  H2SO4 per liter and stored at 4C
          Even when preserved  in this manner, conversion of organic nitrogen to ammonia may
          occur  Preserved samples should be analyzed as soon as possible
5    Interference
     5 1  High nitrate concentrations (10X or more than the  TKN level) result m low  TKN
          values The reaction between nitrate and ammonia can be prevented by the use of an
          anion exchange resin (chloride form) to remove the nitrate prior to the TKN analysis

Approved for NPDES
Issued  1971
Editorial revision 1974 and 1978

                                         351 3-1

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6.   Apparatus
     6.1   Digestion apparatus  A Kjeldahl digestion apparatus with 800 or  100 ml flasks and
           suction takeoff to remove SO3 fumes and water
     6 2   Distillation apparatus  The macro Kjeldahl flask is connected to a condenser and an
           adaptor so that the distillate can be collected  Micro  Kjeldahl  steam  distillation
           apparatus is commercially available
     6 3   Spectrophotometer for use at 400 to 425 nm with a light path of 1 cm or longer
7    Reagents
     7.1   Distilled water should be free of ammonia Such water is best prepared by the passage of
           distilled water through an  ion exchange column containing a strongly acidic cation
           exchange resin mixed with a strongly basic anion exchange resin Regeneration of the
           column should be earned out according to the manufacturer's instructions
           NOTE 1: All solutions must be made with ammonia-free water
     7 2   Mercuric sulfate solution Dissolve 8 g red mercuric oxide (HgO) in 50 ml of 1 4 sulfunc
           acid (10 0 ml cone H2SO4  40 ml distilled water) and dilute  to 100 ml with distilled
           water
     7 3   Sulfunc acid-mercuric sulfate-potassium sulfate solution Dissolve 267 g K2SO4 in 1300
           ml distilled water and 400 ml cone H2SO4  Add 50 ml mercunc sulfate solution (7 2) and
           dilute to 2 liters with distilled water
     74   Sodium  hydroxide-sodium  thiosulfate  solution  Dissolve 500 g NaOH  and 25  g
           Na2S2O35H2O in distilled water and dilute to 1 liter
     7 5   Mixed indicator Mix 2 volumes of 0 2% methyl red in 95% ethanol with 1 volume of
           0 2% methylene blue in ethanol Prepare fresh every 30 days
     7 6   Bone acid solution Dissolve 20 g bone acid, H3BO3, in water and dilute to  1 liter with
           distilled water
     7 7   Sulfunc acid, standard solution  (0 02 N) 1 ml = 0 28 mg NH3-N Prepare a stock
           solution of approximately 0  1 N acid by diluting 3 ml of cone  H2SO4 (sp gr  1 84) to 1
           liter with CO2-free distilled water Dilute 200 ml of this solution to 1 liter with CO2-free
           distilled water Standardize the approximately 0 02 N acid so prepared against 0 0200 N
           Na2CO3 solution This last solution is prepared by dissolving 1 060 g anhydrous Na2CO3,
           oven-dried at 140C, and diluting to 1 liter with CO2-free distilled water
           NOTE 2:   An  alternate and  perhaps   preferable  method  is  to  standardize  the
           approximately 0 1 N H2SO4 solution against a 0 100 N Na2CO3 solution  By proper
           dilution the 0 02 N acid can the be prepared
     7.8   Ammonium chlonde, stock solution  1 0 ml = 1 0 mg NH3-N  Dissolve 3 819 g NH4C1
           m water and make up to 1 liter in a volumetric flask with distilled water
     7 9   Ammonium chlonde, standard solution 1 0 ml = 0 01 mg NH3-N Dilute 10 0 ml of the
           stock solution (7 8) with distilled water to 1 liter in a volumetric flask
     7 10  Nessler reagent  Dissolve 100 g of mercuric iodide and 70 g potassium iodide in a small
           volume of distilled water Add this mixture slowly, with stirring, to a cooled solution of
           160 g of NaOH m 500 ml of distilled water Dilute the mixture to 1 liter The solution is
           stable for at least one year if stored m a pyrex bottle out of direct sunlight
                                       351 3-2

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     NOTE 3. Reagents 7 7, 7 8, 7 9, and 7 10 are identical to reagents 6 8, 6 2, 6 3, and 6 6
     described  under  Nitrogen,  Ammonia  (Colonmetric, Titrimetnc,  Potentiometnc-
     Distillation Procedure, Method 350 2)
Procedure
8 1   The distillation apparatus should be pre-steamed before use by distilling all mixture of
     distilled water and sodium hydroxide-sodium thiosulfate solution (7 4) until the distillate
     is ammonia-free  This  operation should be repeated each time the apparatus  is out of
     service long enough to accumulate ammonia (usually 4 hours or more)
8 2   Macro Kjeldahl system
     821  Place a measured sample or the residue from the distillation in  the ammonia
           determination (for Organic Kjeldahl only)  into an 800 ml Kjeldahl flask  The
           sample size can be determined from the following table

              Kjeldahl Nitrogen                                 Sample Size
               in Sample, mg/1                                     ml

                   0-5                                            500
                  5-10                                            250
                10-20                                            100
                20-50                                            50 0
                50-500                                            25 0

           Dilute the sample, if required, to 500 ml with distilled water, and add 100 ml
           sulfunc acid-mercuric sulfate-potassmm  sulfate solution (7 3) Evaporate the
           mixture in the Kjeldahl apparatus until SO3 fumes are given off and the solution
           turns colorless or pale yellow Continue heating for 30 additional minutes  Cool the
           residue and add 300 ml distilled water
     822  Make the digestate alkaline  by  careful addition of 100 ml of sodium hydroxide -
           thiosulfate solution (7 4) without mixing
           NOTE 5- Slow addition of the heavy caustic solution down the tilted neck of the
           digestion flask will cause heavier solution to underlay  the aqueous sulfunc acid
           solution without loss of free-ammonia Do not mix until the digestion flask has
           been connected to the distillation apparatus
     823  Connect the Kjeldahl flask to the condenser with the tip  of condenser or an
           extension of the condenser tip below the level of the boric acid solution (7 6) in the
           receiving flask
     824  Distill 300 ml at the rate of 6-10 ml/mm, into 50 ml of 2% bone acid  (7 6)
           contained in a 500 ml Erlenmeyer flask
     825  Dilute the distillate to 500 ml in the flask These flasks should be marked at the 350
           and the 500 ml volumes  With such marking, it is not necessary to transfer the
           distillate to volumetric flasks For concentrations above  1 mg/1, the ammonia can
           be determined titnmetncally For concentrations below this value, it is determined
           colonmetncally The potentiometnc method is applicable to the range 0 05 to 1400
           mg/1
                                    351 3-3

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8.3  Micro Kjeldahl system
     8.3 1  Place 50 0 ml of sample or an aliquot diluted to 50 ml m a 100 ml Kjeldahl flask
           and add 10 ml sulfunc acid-mercuric sulfate-potassium sulfate solution (7 3)
           Evaporate the mixture in the Kjeldahl apparatus until SO3 fumes are given off and
           the solution  turns colorless or pale yellow  Then digest for an additional 30
           minutes  Cool the residue and add 30 ml distilled water
     832  Make the digestate alkaline by careful addition of 10 ml of sodium hydroxide-
           thiosulfate solution (7 4) without mixing Do not mix until the digestion flask has
           been connected to the distillation apparatus
     833  Connect the  Kjeldahl flask to the condenser with the tip of condenser or an
           extension of the condenser tip below the level of the bone acid solution (7 6) in the
           receiving flask or 50 ml short-form Nessler tube
     8.3 4  Steam distill 30 ml at the rate of 6-10 ml/mm , into 5 ml of 2% boric acid (7 6)
     835  Dilute the distillate to 50 ml For concentrations above 1 mg/1 the ammonia can be
           determined titnmetncally For concentrations below this value, it is determined
           colonmetncally The potentiometnc method is applicable to the range 0 05 to 1400
           mg/1
8.4  Determination of ammonia in distillate Determine the ammonia content of the distillate
     titnmetncally, colonmetncally, or potentiometncally, as descnbed below
     841  Titnmetnc determination Add 3 drops of the mixed indicator (7 5) to the distillate
           and titrate the ammonia with the  0 02 N H2SO4 (7 7), matching the endpomt
           against a blank containing the same volume  of distilled water and H3BO3 (7 6)
           solution
     842  Colonmetnc determination Prepare a senes of Nessler tube standards as follows

              ml  of Standard
         1 0 ml  =  0 01 mg NH3-N                        mg NH3-N/50 0 ml

                  00                                         00
                  05                                         0 005
                  10                                         0010
                  20                                         0 020
                  40                                         0 040
                  50                                         0 050
                  80                                         0 080
                 100                                         010

           Dilute each tube to 50 ml with ammonia free water, add 1 ml of Nessler Reagent
           (7 10) and mix  After 20  minutes read the absorbance at 425 nm against the blank
           From the values obtained for the standards plot absorbance vs  mg NH3-N for the
           standard curve  Develop color in the 50 ml diluted distillate in exactly the same
           manner and read mg NH3-N from the standard curve
     8 4.3  Potentiometnc  determination Consult the method entitled Nitrogen, Ammonia
           Potentiometnc, Ion Selective Electrode Method, (Method 350 3) in this manual
     844  It is not imperative that all standards be treated in the same manner as the samples
           It is recommended that at least 2 standards (a high and low) be digested, distilled,
                                    351 3-4

-------
            and compared to similar values on the curve to insure that the digestion-distillation
            technique is reliable If treated standards do not agree with untreated standards the
            operator should find the cause of the apparent error before proceeding
 Calculation
 9 1  If the titnmetnc procedure is used, calculate Total Kjeldahl Nitrogen, in mg/1, m the
      original sample as follows
                          TKN,mg/l=  (A - B)N x F x 1,000
                                                 S
      where
      A = milhliters of standard 0 020 N H2SO4 solution used in titrating sample
      B = milhliters of standard 0 020 N H2SO4 solution used m titrating blank
      N = normality of sulfunc acid solution
      F = milliequivalent weight of nitrogen (14 mg)
      S = milhliters of sample digested

      If the sulfunc acid is exactly 0 02 N the formula is shortened to
                         TKN, mg/1 =   x 28
92   If the Nessler procedure is used, calculate the Total Kjeldahl Nitrogen, m mg/1, in the
      original sample as follows
                         TKN, mg/1 = A Xp'    x  -.
      where
      A = mg NH3-N read from curve
      B = ml total distillate collected including the H3BO3
      C = ml distillate taken for Nesslenzation
      D = ml of original sample taken

9 3   Calculate Organic Kjeldahl Nitrogen in mg/1, as follows
      Organic Kjeldahl Nitrogen = TKN -(NH3-N )
                                    351 3-5

-------
      9 4   Potentiometric determination  Calculate Total Kjeldahl Nitrogen, in mg/1,  in the
           original sample as follows


                                    TKN, mg/1 = -jj x A
           where
           A = mg NH3-N/1 from electrode method standard curve
           B = volume of diluted distillate in ml
           D = ml of original sample taken

10.  Precision
     10 1  Thirty-one analysts in twenty laboratories analyzed natural water samples containing
           exact increments of organic nitrogen, with the following results
      Increment as
    Nitrogen, Kjeldahl
       mg N/liter

          020
          031
          410
          461
   Precision as
Standard Deviation
   mg N/liter

      0197
      0247
      1056
      1 191
           Accuracy as
  Bias,
+ 1554
+  545
+  103
 - 167
   Bias,
mg N/liter

   +003
   +002
   +004
   -008
(FWPCA Method Study 2, Nutrient Analyses)
                                       Bibliography

1.   Standard  Methods  for the Examination of Water and  Wastewater,  14th Edition, p 437,
     Method 421 (1975)
2.   Schlueter, Albert, "Nitrate Interference In Total Kjeldahl Nitrogen Determinations and Its
     Removal by Amon Exchange Resins", EPA Report 600/7-77-017
                                         351 3-6

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                        NITROGEN, KJELDAHL,  TOTAL

              Method 351.4 (Potentiometric, Ion Selective Electrode)

                                                                STORET NO. 00625

 1     Scope and Application
      1 1   This method is applicable to the measurement of TKN in drinking and surface water,
           domestic and industrial wastes
      1 2   This method covers the range from 0 03 to 25 mg TKN/1
 2     Summary of Method
      2 1   Following digestion and cooling, distilled water is added to the digestion flask and the
           pH adjusted to between 3 and 4 5 by the addition of 10 N NaOH The sample is cooled
           and transferred to a 100 ml beaker After inserting the electrode into the sample, NaOH-
           Nal-EDTA is added and the ammonia measured  (Ethylene diamine tetraacetic acid
           (EDTA) is  added to the alkaline  reagent (NaOH-Nal) to  prevent precipitation of
           hydroxides,  thereby avoiding deposition on the electrode membrane)
 3     Sample Handling and Preservation
      3 1   Samples may be preserved by addition of 2 ml of cone H2SO4 per liter and stored at 4C
           Even when preserved in this manner, conversion of organic nitrogen  to ammonia may
           occur Preserved samples should be analyzed as soon as possible
 4     Interferences
      4 1   Interference from metals is eliminated with the addition of Nal
      4 2   High nitrate concentrations (10X or more than the TKN level) result in low TKN
           values The  reaction between nitrate and ammonia can be prevented by the use of an
           anion exchange resin (chloride form) to remove the nitrate prior to the TKN analysis
 5     Apparatus
      5 1   Electrometer (pH meter) with expanded mV scale
      5 2   Ammonia selective electrode, such as Orion Model 95-10
      5 3   Magnetic stirrer, thermally insulated and Teflon-coated stirring bar
      5 4   Digestion apparatus  A Kjeldahl digestion apparatus with 800 or 100 ml flasks and
           suction take off to remove SO3 fumes and water
      5 5   Techmcon Block Digester BD-40
 6     Reagents
      6 1   Distilled water should  be free of ammonia Such  water is best prepared by passing
           distilled water through an ion exchange column containing  a strongly acidic cation
           exchange resin mixed with a strongly basic anion exchange resin Regeneration of the
           column should be carried out according to the manufacturer's instructions
           NOTE 1: All solutions must be made with ammonia-free water
      6 2   Mercuric sulfate solution  Dissolve 8 g red mercuric oxide (HgO) in 50  ml of 1 4 sulfunc
           acid (10 0 ml cone H2SO4  40 ml distilled water) and dilute to 100 ml with distilled water

Pending approval for NPDES
Issued 1978

                                        351 4-1

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6 3   Sulfunc acid-mercuric sulfate-potassium sulfate solution Dissolve 267 g K2SO4 in 1300
      ml distilled water and 400 ml cone H2SO4 Add 50 ml mercuric sulfate solution (6 2) and
      dilute to 2 liters with distilled water
6.4   Sodium hydroxide ION Dissolve 400 g NaOH in 600 ml of ammonia-free water, cool
      and dilute to 1 liter
6.5   Sodium Hydroxide, Sodium Iodide and EDTA Solution Dissolve 400 g of NaOH, 300 g
      Nal and 2 g of EDTA m 700 ml of ammonia-free water, cool and dilute to 1 liter
6 6   Ammonium chloride, stock solution  1 0 ml = 1 0 mg NH3-N  Dissolve 3 819 g NH4C1
      m water and make up to 1 liter m a volumetric flask with distilled water
6.7   Ammonium chloride, standard solution  1 0 ml = 0 01 mg NH3-N Dilute 10 0 ml of the
      stock solution (6 6) to 1 liter with distilled water m a volumetric flask
Procedure
7.1   Macro Kjeldahl system
      7 7.1  Place a measured sample or the residue from the distillation in the ammonia
           determination (for Organic Kjeldahl only) into an 800 ml Kjeldahl flask The
           sample size can be determined from the following table

                     Kjedahl Nitrogen                      Sample Size
                      m Sample,  mg/1                          ml
                         0-5                               500
                         5-10                              250
                        10-20                              100
                        20-50                               50 0
                        50-500                               25 0

           Dilute the sample, if required, to 500 ml with distilled water, and add 100 ml
           sulfunc acid-mercuric sulfate-potassium sulfate solution (6 3)  and evaporate the
           mixture m the Kjeldahl apparatus until SO3 fumes are given off and the solution
           turns colorless or pale yellow Continue heating for 30 additional minutes Cool the
           residue and add 500 ml distilled water and mix
7 2   Micro Kjeldahl system
      721  Place 50 0 ml of sample,  or an aliquot diluted to 50 ml, in a 100 ml Kjeldahl flask
           and  add  10 ml sulfunc acid-mercuric sulfate-potassium sulfate solution (6 3)
           Evaporate the mixture in the Kjeldahl apparatus until SO3 fumes are given off and
           the solution turns colorless or pale yellow Then digest for an additional 30
           minutes Cool the residue, add 44 ml distilled water and mix
7 3   Block Digester
      731  Place 20 ml of sample, or an aliquot diluted to 20 ml, in the digestion tube Add 5
           ml of sulfunc acid-mercuric sulfate-potassium sulfate solution (6 3) and mix Add
           4-8 Teflon boiling stones
      732  Place tubes in digestor that has been preheated to 200C
      7 3 3  Set low temperature at 200C for 1 hour, the high temperature  at 380C and total
           time  for two and one half hours
                                     3514-2

-------
      734 After the temperature of the block has reached 380C, the time should be set for 30
           minutes Longer time and higher temperature may result in complete loss of the
           acid
      735 Cool, add 25 ml of ammonia-free water and mix
7 4   Electrode analysis
      741 All standards should be treated as the samples and should contain the same
           concentration of sulfuric acid-mercuric sulfate-potassium sulfate solution (6 3)
      742 Macro Kjeldahl system
           To a 100 ml aliquot, add  15 ml of 10 N NaOH (6 4),  mix and cool to room
           temperature Immerse the electrode in the sample solution and add 4 ml of NaOH-
           Nal-EDTA reagent (6 5) while mixing Allow the electrode to remain immersed in
           the solution until a stable reading is obtained
      743 Micro Kjeldahl system
           Add 6 ml of 10 N NaOH solution (6 4), cool to room temperature and transfer the
           sample to a 100 ml beaker Immerse the electrode m the sample solution and add 4
           ml of NaOH-Nal-EDTA reagent (6 5) while mixing Allow the electrode to remain
           immersed in the solution until a stable reading is obtained
      744 Block Digestor
           Add 3 ml of 10 N NaOH (6 4), cool to room temperature, dilute to 50 ml and
           transfer to a 100 ml beaker Immerse the electrode in the sample and add 2 ml of
           NaOH-Nal-EDTA  reagent (6 5) while mixing  Allow the electrode to remain
           immersed in the solution until a stable reading is obtained
Calculation
Using semiloganthmic graph paper, plot the concentration of ammonia in mg NH3-N  on the
log axis vs the electrode potential developed in the standard on the linear axis, starting with the
lowest concentration at the bottom of the scale
                         mgTKN/l = (A - B)x  1.000
     where
     A = mg NH3-N read from standard curve
     B = mg NH3-N in blank
     C = ml of original sample taken

Precision and Accuracy
9 1  Precision and accuracy data are not available at this time

                                 Bibliography

Schlueter, A, "Nitrate  Interference  in Total Kjeldahl Nitrogen Determinations and  its
Removal by Amon Exchange Resin", EPA-600/7-77-017
                                    3514-3

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                               NITROGEN, NITRATE

                        Method  352.1  (Colorimetric,  Brucine)

                                                           STORET NO. Total 00620

 1    Scope and Application
      1 1   This method is applicable to the analysis of drinking, surface and saline waters, domestic
           and industrial wastes Modification can be made to remove or correct for turbidity, color,
           salinity, or dissolved organic compounds in the sample
      1 2   The applicable range of concentrations is 0 1 to 2 mg NO3-N/hter
 2    Summary of Method
      2 1   This method is based upon the reaction of the nitrate ion with brucine sulfate in a 13 N
           H2SO4 solution at a temperature of 100C The color of the resulting complex is measured
           at 410 nm Temperature control of the color reaction is extremely critical
 3    Sample Handling and Preservation
      3 1   Analysis should be made as soon as possible If analysis can be made within 24 hours, the
           sample should be preserved by refrigeration  at 4C  When samples must be stored for
           more than 24 hours, they should be preserved with sulfunc acid (2 ml cone  H2SO4 per
           liter) and refrigeration
 4    Interferences
      4 1   Dissolved organic matter will cause an off color in 13 N H2SO4 and must be compensated
           for by additions of  all reagents except the brucme-sulfamlic acid reagent This also
           applies to natural color present not due to dissolved organics
      42   The effect of salinity is eliminated by addition of sodium chloride to the blanks, standards
           and samples
      4 3   All strong oxidizing  or reducing agents interfere The presence of oxidizing agents may
           be determined with a total residual chlorine test kit
      44   Residual chlorine interference is eliminated by the addition of sodium arsemte
      4 5   Ferrous and ferric iron and quadrivalent manganese give slight positive interferences, but
           in concentrations less than 1 mg/1 these are negligible
      4 6   Uneven heating of the samples and standards during the reaction time will result in
           erratic values The necessity for absolute control of temperature during the critical color
           development period cannot be too strongly emphasized
5     Apparatus
      5 1   Spectrophotometer or filter photometer suitable for measuring absorbance at 410 nm
      5 2   Sufficient number of 40-50 ml glass sample tubes for reagent blanks, standards and
           samples
      5 3   Neoprene coated wire racks to hold sample tubes
      5 4   Water bath suitable for use at 100C This bath should contain a stirring mechanism so
           that all tubes are at the same temperature and should be of sufficient capacity to accept

Approved for NPDES and SDWA
Issued 1971

                                         352 1-1

-------
     the required number of tubes without significant drop in temperature when the tubes are
     immersed
5 5  Water bath suitable for use at 10-15C
Reagents
6 1  Distilled water free of nitrite and nitrate is to be used in preparation of all reagents and
     standards
6 2  Sodium chloride solution (30%) Dissolve 300 g NaCl in distilled water and dilute to 1
     liter
6 3  Sulfunc acid solution  Carefully add 500 ml cone H2SO4 to 125 ml distilled water  Cool
     and keep tightly stoppered to prevent absorption of atmospheric moisture
64  Brucme-sulfanilic     acid     reagent     Dissolve    1     g    brucine    sulfate
     [(C23H26N2O4)2H2SO47H2O] and 0 1 g sulfamhc acid (NH2C6H4SO3HH2O) in 70  ml
     hot distilled water Add 3 ml cone  HC1, cool, mix and dilute to 100 ml with distilled
     water Store in a dark bottle at 5C This solution is stable for several months, the pink
     color that develops slowly does not effect its usefulness  Mark bottle with warning
     CAUTION Brucine Sulfate is toxic, take care to avoid ingestion
6 5  Potassium nitrate stock solution  1 0 ml = 0 1 mg NO3-N Dissolve 0 7218 g anhydrous
     potassium nitrate (KNO3) in distilled water and dilute to 1 liter in a volumetric flask
     Preserve with 2 ml chloroform per liter This solution is stable for at least 6 months
6 6  Potassium nitrate standard solution  1 0 ml = 0 001 mg NO3-N Dilute 10 0 ml of the
     stock solution (6 5) to 1 liter in a volumetric flask  This standard solution should be
     prepared fresh weekly
6 7  Acetic acid (1 + 3) Dilute 1 volume glacial acetic acid (CH3COOH) with 3 volumes of
     distilled water
6 8  Sodium hydroxide (IN) Dissolve 40  g of NaOH in distilled water  Cool and dilute to 1
     liter
Procedure
7.1  Adjust the pH of the samples to approximately 7 with acetic acid (6 7)  or sodium
     hydroxide (6 8) If necessary, filter to remove turbidity
7 2  Set up the required number of sample tubes in the rack to  handle reagent blank,
     standards and samples Space tubes evenly throughout the rack to allow for even flow of
     bath water between the tubes This  should assist in achieving uniform heating of all
     tubes
73  If it is necessary to correct for color or dissolved organic matter which will cause color on
     heating, a set of duplicate samples must be run to which all reagents except the brucme-
     sulfamhc acid have been added
7 4  Pipette 10 0 ml of standards and samples or an aliquot of the samples diluted to 10 0 ml
     into the sample tubes
75  If the samples are saline, add 2 ml of the 30%  sodium chloride solution (6 2) to the
     reagent blank, standards and samples For fresh water samples, sodium chloride solution
     may be omitted  Mix contents of tubes by swirling  and place rack in cold water bath
     (0-10C)
                                     352 1-2

-------
     7 6   Pipette 10 0 ml of sulfunc acid solution (6 3) into each tube and mix by swirling Allow
          tubes to come to thermal equilibrium in the cold bath Be sure that temperatures have
          equilibrated in all tubes before continuing
     7 7   Add 0 5 ml brucine-sulfamhc acid reagent (6 4) to each tube (except the interference
          control tubes, 7 3) and carefully mix by swirling, then place the rack of tubes in the 100C
          water bath for exactly 25 minutes
          Caution Immersion of the tube rack into the bath should not decrease the temperature of
          the bath more than 1 to 2C In order to keep this temperature decrease to an absolute
          minimum, flow of bath water between the tubes should not be restricted by crowding too
          many tubes into the rack If color development in the standards reveals discrepancies in
          the procedure, the operator should repeat the procedure after reviewing the temperature
          control steps
     7 8   Remove rack of tubes from the hot water bath and immerse in the cold water bath and
          allow to reach thermal equilibrium (20-25C)
     7 9   Read absorbance against the reagent blank at 410 nm using a 1 cm or longer cell
     Calculation
     8 1   Obtain a standard curve by plotting the absorbance of standards run  by the above
          procedure against mg NO3-N/1 (The color reaction does not always follow Beer's law)
     8 2   Subtract the absorbance of the sample without the brucine-sulfamhc reagent from the
          absorbance  of the sample containing brucme-sulfamlic acid and determine  mg
          NO3-N/1  Multiply by an appropriate dilution factor if less than  10 ml of sample is
          taken
     Precision and Accuracy
     9 1   Twenty-seven analysts in fifteen laboratories analyzed natural water samples containing
          exact increments of inorganic nitrate, with the following results
      Increment as
    Nitrogen, Nitrate
       mg N/liter

          0 16
          019
          108
          124
   Precision as
Standard Deviation
   mg N/hter

      0092
      0083
      0245
      0214
Accuracy as
Bias,
-679
+ 830
+412
+ 282
Bias,
mg N/lrter
-001
+002
+004
+004
(FWPCA Method Study 2, Nutrient Analyses)

                                       Bibliography

1    Standard Methods for the Examination  of Water and Wastewater,  14th  Edition, p 427,
     Method 419D (1975)
2    Annual Book of ASTM Standards, Part 31, "Water", Standard D 992-71, p 363 (1976)
3    Jenkins, D , and Medsken, L, "A Brucine Method for the Determination of Nitrate in Ocean,
     Estuanne, and Fresh Waters", Anal Chem , 36, p 610, (1964)
                                         352 1-3

-------
                        NITROGEN, NITRATE-NITRITE

         Method 353.1 (Colorimetric,  Automated, Hydrazine Reduction)

                                                        STORET  NO. Total 00630

     Scope and Application
     1 1   This method is applicable to drinking and surface water, and domestic and industrial
          wastes The applicable range of this method is 0 01-10 mg/1 nitrate-nitrite  nitrogen
          Approximately 20 samples per hour can be analyzed
     Summary of Method
     2 1   Nitrate is reduced to nitrite with hydrazme sulfate and the nitrite (that originally present
          plus reduced nitrate) is determined by diazotizing with sulfamlamide and coupling with
          N-(l-naphthyl)-ethylenediamme  dihydrochlonde to form a highly colored azo dye
          which is measured colonmetrically
     Sample Handling and Preservation
     3 1   Analysis should be made as soon as possible  If analysis can be made within 24 hours,
          samples should be preserved by refrigeration at 4C  When samples must be stored for
          more than 24 hours, they should be preserved with 2 ml of sulfunc acid (H2SO4) per liter
          and refrigerated
     Interferences
     4 1   Sample color that absorbs in the photometric range used for analysis will interfere
     4 2   The apparent NO3 and NO2 concentrations varied 10 percent with concentrations of
          sulfide ion up to 10 mg/1
     Apparatus
     5 1   Sampler
     5 2   Manifold AAI or AAII
     5 3   Proportioning Pump
     5 4   Heating bath 32C AAI or 37C AAII
     5 5   Continuous filter
     5 6   Colorimeter equipped with an 8 mm, 15 mm or 50 mm flow cell and 529 nm filters
     Reagents
     6 1   Color developing reagent To approximately 500 ml of distilled water  add 200 ml
          concentrated phosphoric acid (sp gr  1 834),  10 g sulfamlamide (H2NC6H4SO2NH2)
          followed by 0 8 g N (1-Naphthyl) ethylenediamme dihydrochlonde Dilute the solution
          to 1 liter with distilled water and store in a dark bottle in the refrigerator This solution is
          stable for approximately 1 month
     6 2   Copper sulfate stock solution Dissolve 2 5 g of copper  sulfate   (CuSO45H2O) in
          distilled water and dilute to 1 liter
Approved for NPDES  and SDWA
Issued  1971
Reissued with revision  1978

                                        353 1-1

-------
      6 3   Copper sulfate dilute solution Dilute 20 ml of stock solution (6 2) to 2 liters with distilled
            water
      6.4   Sodium hydroxide stock solution, (ION) Dissolve 400 g NaOH m 750 ml distilled water,
            cool and dilute to 1 liter
      6 5   Sodium hydroxide (1 ON) Dilute 100 ml of stock NaOH solution (6 4) to 1 liter
      6 6   Hydrazme sulfate stock solution Dissolve 27 5 g of hydrazine sulfate (N2H4H2SO4) in
            900 ml of distilled water and dilute to 1 liter This solution is stable for approximately 6
            months  CAUTION Toxic if ingested Mark container with appropriate warning
      6 7   Hydrazme sulfate dilute solution
            671 AAI Dilute 55 ml of stock solution (6 6) to 1 liter
            672 AAII Dilute 22 ml of stock solution (6 6) to 1 liter
      6 8   Stock nitrate solution  (100 mg/1 NO3-N) Dissolve 0 7218 g of KNO3, oven dried at
            100-105C for 2 hours, in distilled water and dilute to  1 liter  Add 1 ml chloroform as a
            preservative Stable for 6 months 1  ml = 0 1 mg N
      6.9   Stock nitrite solution (100 mg/1 NO2-N) Dissolve 0 6072 g KNO2 in 500 ml of distilled
            water and dilute to 1 liter Preserve with 2 ml of chloroform and keep under refrigeration
            1 ml = 0 1 mg N
      6 10  Standard nitrate solution Dilute 100 ml of stock nitrate solution (6 8) to 1 liter 1 ml =
           OOlmgN
      6 11 Using the  stock nitrate solution  (6 8), prepare  the  following standards in 100  ml
           volumetric flasks At least one nitrite standard should be compared to a nitrate standard
           at the concentration to verify the efficiency of the reduction

                  Cone,  mg NO3-N/1                        ml of stock solution/100 ml

                        05                                            05
                         10                                             10
                        20                                            20
                        30                                            30
                        40                                            40
                        50                                            50
                        80                                            80
                       100                                            100

           For standards in the range of 0 01 mg/1 use the standard nitrate solution
7.   Procedure
     7.1   Set up the manifold as shown in Figure 1  (AAI) or Figure 2 (AAII)  The continuous
           filter must be used to remove the precipitate
     7 2   Allow both colorimeter and recorder to warm up for 30 minutes  Obtain a stable baseline
           with all reagents, feeding distilled water through the sample line
     7 3   Run a 2 0 mg/1 NO3-N and a 2 0 mg/1 NO2-N standard through the system to check for
           100% reduction of nitrate to nitrite  The two peaks should be of equal height If they are
           not, the concentration of the hydrazine sulfate solution must be adjusted as follows If the
           NO3 peak is lower than that of the NO2 peak the concentration of hydrazine sulfate
           should be increased until they are equal  If the NO3 peak is higher than the nitrite, the
           concentration  of the  hydrazine  sulfate   should  be reduced   When the correct
                                          353 1-2

-------
          concentration of hydrazme sulfate has been determined, no further adjustment should be
          necessary
     7 4  Place appropriate nitrate standards in the sampler in order of decreasing concentration
          of nitrogen Complete loading tray with unknown samples
     7 5  For both the AAI and the AAII use a 2 minute sampling rate
8    Calculation
     8 1  Prepare a standard curve by plotting peak heights of processed standards against known
          concentrations  Compute concentrations of samples by comparing sample peak heights
          with the standard curve
9    Precision and Accuracy
     91  In  a single laboratory using drinking water, surface  water and industrial  waste at
          concentrations  of  0 39, 115,  1 76 and 4 75 ug NO3-N/1, the standard deviations
          were  +002,  001, 002 and  +0 03, respectively In a single laboratory using drinking
          water at concentrations of 0 75 and 2 97 the recoveries were 99% and 101%

                                      Bibliography

1    Kamphake, L , Hannah, S , and Cohen, J , "Automated Analysis For Nitrate by Hydrazme
     Reduction", Water Research 1,205 (1967)
                                         353 1-3

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                        NITROGEN,  NITRATE-NITRITE

          Method  353.2 (Colorimetric, Automated, Cadmium Reduction)

                                                         STORET NO. Total 00630

1    Scope and Application
     1 1   This method pertains to the determination of nitrite singly, or nitrite and nitrate
          combined m surface and saline waters,  and domestic and industrial wastes  The
          applicable range of this method is 0 05 to 10 0 mg/1 nitrate-nitrite nitrogen The range
          may be extended with sample dilution
2    Summary of Method
     21   A filtered sample is passed through a column containing granulated copper-cadmium to
          reduce nitrate to nitrite  The nitrite (that originally present plus reduced nitrate) is
          determined  by diazotizing with sulfamlamide and  coupling with  N-(l-naphthyl)-
          ethylenediamme dihydrochlonde to form a highly colored azo dye which is measured
          colonmetncally  Separate,  rather than combined nitrate-nitrite, values are readily
          obtained by carrying out the procedure first with, and then without, the Cu-Cd reduction
          step
3    Sample Handling and Preservation
     3 1   Analysis should be made as soon as possible If analysis can be made within 24 hours, the
          sample should be preserved by refrigeration at 4C When samples must be stored for
          more than 24 hours, they should be preserved with sulfuric acid (2 ml cone H2SO4 per
          liter) and refrigeration
           Caution Samples for reduction column must not be preserved with mercuric chloride
4    Interferences
     4 1    Build up of suspended matter in the reduction column will restrict sample flow  Since
           nitrate-nitrogen is found in a soluble state, the sample may be pre-filtered
     4 2   Low results might be obtained  for samples that contain high concentrations of iron,
           copper or other metals EDTA is added to the samples to eliminate this interference
     4 3   Samples that contain large concentrations of oil and grease will coat the surface of the
           cadmium This interference is eliminated by pre-extracting the sample with an organic
           solvent
5    Apparatus
     5 1   Techmcon Auto Analyzer (A AI or A All) consisting of the following components
           511  Sampler
           512 Manifold (AAI) or analytical cartridge (AAII)
           513 Proportioning Pump
           5 1 4 Colorimeter equipped with a 15 mm or 50 mm tubular flow cell and 540 nm filters
           515 Recorder

Approved for NPDES and SDWA
Issued 1971
Editorial revision 1974 and 1978

                                         353 2-1

-------
           516 Digital printer for AAII (Optional)
6.    Reagents
     6 1   Granulated cadmium 40-60 mesh (MCB Reagents)
     6 2   Copper-cadmium The cadmium granules (new or used) are cleaned with dilute HC1
           (6 7) and coppenzed with 2% solution of copper sulfate (6 8) in the following manner
           6 2 1 Wash the cadmium with HC1 (6 7) and rinse with distilled water The color of the
                cadmium so treated should be silver
           622 Swirl 10 g cadmium in 100 ml portions of 2% solution of copper sulfate (6 8) for
                five minutes or until blue color partially fades, decant and repeat with fresh copper
                sulfate until a brown colloidal precipitate forms
           623 Wash the cadmium-copper with distilled water (at least 10 times) to remove all the
                precipitated copper The color of the cadmium so treated should be black
     6.3   Preparation of reduction column AAI  The reduction column is an 8 by 50 mm glass tube
           with the ends reduced in diameter to permit insertion into the system Copper-cadmium
           granules (6 2) are placed in the column between glass wool plugs  The packed reduction
           column is placed m an up-flow 20 incline to minimize channeling  See Figure 1
     6 4   Preparation of reduction column AAII The reduction column  is a U-shaped, 35 cm
           length, 2 mm I D glass tube (frote* 1)  Fill the reduction column with distilled water to
           prevent entrapment of air bubbles during the  filling operations Transfer the  copper-
           cadmium granules (6 2) to the reduction column and place a glass wool plug in each end
          To prevent entrapment of air bubbles in the reduction column be sure that all pump tubes
          are filled with reagents before putting the column into the analytical system
          NOTE 1: A 0 0811D pump tube (purple) can be used in place of the 2 mm glass tube
     6 5  Distilled water  Because of possible contamination, this should be prepared by  passage
          through an ion exchange column comprised of a mixture of both strongly acidic-cation
          and strongly basic-amon exchange resms The regeneration of the ion exchange  column
          should be earned out according to the manufacturer's instructions
     6.6  Color reagent To approximately 800 ml of distilled water, add,  while stirring, 100 ml
          cone  phosphoric acid,  40  g sulfamlamide, and 2  g N-1-naphthylethylenediamme
          dihydrochlonde Stir .until dissolyed and  dilute to 1 liter Store in brown bottle and keep
          m the dark when not in use This solution is stable for several months
     6.7  Dilute hydrochloric acid, 6N Dilute 50 ml of cone HC1 to 100 ml with distilled water
     6 8   Copper sulfate solution, 2% Dissolve 20 g of CuSO45H2O in 500 ml of distilled water
          and dilute to 1 liter
     6 9   Wash solution  Use distilled  water for unpreserved samples  For samples preserved with
          H2SO4, use 2 ml H2SO4 per liter of wash water
     6 10  Ammonium chlonde-EDT,A  splution  Dissolve 85  g of reagent  grade  ammonium
          chloride and 0 1 g of disodium ethylened'iamme tetracetate in  900 ml of distilled water
          Adjust the pH to 8 5 with cone ammonium hydroxide and dilute  to 1 liter Add 1/2 ml
          Bnj-35 (available from Techmcon Corporation)
                                         353 2-2

-------
                  INDENTATIONS FOR
                SUPPORTING CATALYST
GLASS WOOL
Cd-TURNINGS
            TILT COLUMN TO  20 POSTION
   FIGURE 1. COPPER CADMIUM REDUCTION COLUMN
                (1 1/2 ACTUAL SIZE)
                    353 2-3

-------
 6 11.  Stock nitrate solution Dissolve 7 218 g KNO3 and dilute to 1 liter m a volumetric flask
       with distilled water Preserve with 2 ml of chloroform per liter Solution is stable for 6
       months 1 ml = 1 0 mg NO3-N
 6 12  Stock nitrite solution Dissolve 6 072 g KNO2 in 500 ml of distilled water and dilute to 1
       liter in a volumetric flask Preserve with 2 ml of chloroform and keep under refrigeration
       10ml= 10mgNO2-N
 6 13  Standard nitrate solution  Dilute 10 0 ml of stock nitrate solution (6 11) to 1000 ml
       10 ml  =  001mgNO3-N Preserve with 2 ml of chloroform per liter Solution is stable
       for 6 months
 6 14  Standard nitrite solution Dilute 10 0 ml of stock nitrite (6 12) solution to 1000 ml
       1 0 ml  =  0 01 mgNO2-N Solution is unstable, prepare as required
 6 15 Using standard nitrate solution (6 13), prepare the following standards in  1000 ml
      volumetric flasks  At least one nitrite standard should be compared to a nitrate standard
      at the same concentration to verify the efficiency of the reduction column
          Cone, mgNO2-N or  NO3-N/1

                  00
                  005
                  010
                  020
                  050
                  100
                  200
                  400
                  600
                                                      ml Standard Solution/100 ml

                                                                 0
                                                                 05
                                                                 10
                                                                 20
                                                                 50
                                                                 100
                                                                 200
                                                                 400
                                                                 600
      NOTE 2' When the samples to be analyzed are saline waters, Substitute Ocean Water
      (SOW) .should be used for preparing the standards, otherwise, distilled water is used  A
      tabulation of SOW composition follows
     NaCl - 24 53 g/1
     CaCl2 - 1 16 g/1
     KBr  - 0 10  g/1
     NaF  - 0 003 g/1
                                MgCl2 -  5 20 g/1
                                KC1 - 0 70  g/1
                                H3B03 - 0 03 g/1
Na2S04 - 4 09 g/1
NaHCO3 -  0 20 g/1
SrCl2 - 0 03 g/1
Procedure
7 1   If the pH of the sample is below 5 or above 9, adjust to between 5 and 9 with either cone
     HClorconc NH4OH
     Set up the manifold as shown m Figure 2 (AAI) or Figure 3 (AAII) Note that reductant
     column should be in 20 incline position (AAI)  Care should be taken not to introduce air
     into reduction column on the AAII
     Allow both colorimeter and recorder to warm up for 30 minutes Obtain a stable baseline
     with all reagents, feeding distilled water through the sample line
     NOTE 3: Condition column by running 1 mg/1 standard for 10 minutes if a new
     reduction  column is being used  Subsequently wash the column with reagents for 20
     minutes
72
73
                                    353 2-4

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3
4
     7 4  Place appropriate nitrate and/or nitrite standards in sampler in order of decreasing
          concentration of nitrogen Complete loading of sampler tray with unknown samples
     7 5  For the AAI system, sample at a rate of 30/hr,  1 1 For the AAII, use a 40/hr, 4 1 cam
          and a common wash
     7 6  Switch sample line to sampler and start analysis
     Calculations
     8 1  Prepare appropriate standard curve or curves derived from processing NO2 and/or NO3
          standards through manifold  Compute concentration of samples  by comparing sample
          peak heights with standard curve
     Precision and Accuracy
     9 1  Three laboratories participating in an EPA Method Study, analyzed four natural water
          samples containing exact increments of inorganic nitrate, with the following results
      Increment as
    Nitrate Nitrogen
       mg N/hter

          029
          035
          231
          248
                        Precision as
                     Standard Deviation
                         mg N/hter

                           0012
                           0092
                           0318
                           0176
Accuracy as
Bias,
+ 575
+ 18 10
+ 447
-269
Bias,
mg N/hter
+0017
+0063
+0103
-0067
                                      Bibliography
Fiore, J, and O'Brien, J E, "Automation m Sanitary Chemistry - parts 1 & 2 Determination
of Nitrates and Nitrites", Wastes Engineering 33, 128 & 238 (1962)
Armstrong, F A, Stearns, C R, and Strickland, J D , "The Measurement of Upwellmg and
Subsequent Biological Processes by Means of the Techmcon AutoAnalyzer and Associated
Equipment", Deep Sea Research 14, p 381-389 (1967)
Annual Book of ASTM Standards, Part 31, "Water", Standard D1254, p 366 (1976)
Chemical Analyses for Water Quality Manual, Department of the Interior, FWPCA, R A
Taft Sanitary Engineering Center Training Program, Cincinnati, Ohio 45226 (January, 1966)
Annual Book of ASTM Standards, Part 31, "Water", Standard D 1141-75, Substitute Ocean
Water, p 48 (1976)
                                         353 2-5

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                        NITROGEN, NITRATE-NITRITE

            Method  353.3  (Spectrophotometric, Cadmium Reduction)

                                                         STORET  NO. Total 00630

     Scope and Application
     1 1   This method is applicable to the determination of nitrite singly, or nitrite and nitrate
          combined in drinking, surface and saline waters, domestic and industrial wastes The
          applicable range of this method is 0 01 to 1 0 mg/1 nitrate-nitrite nitrogen The range
          may be extended with sample dilution
     Summary of Method
     21   A filtered sample is passed through a column containing granulated copper-cadmium to
          reduce nitrate to  nitrite The nitrite (that  originally present plus reduced nitrate) is
          determined  by diazotizmg  with sulfamlamide and  coupling  with N-(l-naphthyl)-
          ethylenediamme dihydrochlonde to form a highly colored azo dye which is measured
          spectrophotometncally Separate, rather than combined nitrate-nitrite, values are readily
          obtained by carrying out the procedure first with, and then without, the Cu-Cd reduction
          step
     Sample Handling and Preservation
     3 1   Analysis should be made as soon as possible  If analysis can be made within 24 hours, the
          sample should be preserved by refrigeration at 4C When samples must be stored for
          more than 24 hours, they should be preserved with sulfunc acid (2 ml H2SO4 per liter)
          and refrigeration
          Caution Samples for reduction column must not be preserved with mercuric chloride
     Interferences
     4 1   Build up of suspended matter in the reduction column will restrict sample flow Since
          nitrate-nitrogen is found in a soluble state, the sample may be pre-filtered through a glass
          fiber filter or a 0 45 u membrane filter Highly turbid samples may be pretreated with zinc
          sulfate before filtration to remove the bulk of particulate matter present m the sample
     4 2   Low results might be obtained for samples that contain high concentrations of iron,
          copper or other metals EDTA is added to the samples to eliminate this interference
     4 3   Samples that contain large concentrations of oil and grease will coat the surface of the
          cadmium This interference is eliminated by pre-extracting the sample with an organic
          solvent
     4 4   This procedure determines both nitrate and mtnte If only nitrate is desired, a separate
          determination must be made for nitrite and subsequent corrections made The nitrite
          may be determined by the procedure below without the reduction step
Approved for  NPDES and SDWA
Issued 1974
                                         353 3-1

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5.    Apparatus
     5 1   Reduction column  The column in Figure I was constructed from a 100 ml pipet by
           removing the top portion This column may also be constructed from two pieces of
           tubing joined end to end A 10 mm length of 3 cm I D tubing is joined to a 25 cm length
           of 3 5 mm I D tubing
     5 2   Spectrophotometer for use at 540 nm, providing a light path of 1 cm or longer
6.    Reagents
     6.1   Granulated cadmium 40-60 mesh (MCB Reagents)
     6 2   Copper-Cadmium The cadmium granules (new or used) are cleaned with dilute HC1 and
           coppenzed with 2% solution of copper sulfate m the following manner
           621  Wash the cadmium with dilute HC1 (6 10) and rinse with distilled water The color
                of the cadmium should be silver
           622  Swirl 25 g cadmium in 100 ml portions of a 2% solution of copper sulfate (6 11) for
                5 minutes or until blue color partially fades, decant and repeat with fresh copper
                sulfate until a brown colloidal precipitate forms
           623  Wash the copper-cadmium with distilled water (at least 10 times) to remove all the
                precipitated copper  The color of the cadmium so treated should be black
     6 3   Preparation of reaction column Insert a glass wool plug into the bottom of the reduction
           column and fill with distilled water Add sufficient copper-cadmium granules to produce
           a column 18 5 cm  in length Maintain a  level  of distilled water  above  the  copper-
           cadmium granules to eliminate entrapment of air Wash the column with 200 ml of dilute
           ammonium chloride solution (6 5) The column is then activated by passing through the
           column 100 ml of a solution composed of 25 ml of a 1 0 mg/1 NO3-N standard and 75 ml
           of ammonium chloride - EDTA solution (6 4) Use a flow rate between 7 and 10 ml per
           minute
     6.4   Ammonium chloride - EDTA solution Dissolve 13 g ammonium chloride and 1 7 g
           disodium ethylenediamme tetracetate in 900 ml of distilled water  Adjust the pH to 8 5
           with cone ammonium hydroxide (6 9) and dilute to 1 liter
     6 5    Dilute ammonium chlonde-EDTA solution  Dilute 300 ml of ammonium chlonde-
           EDTA solution (6 4) to 500 ml with distilled water
     6 6   Color reagent Dissolve 10 g sulfamlamide and 1 g  N(l-naphthyl)-ethylene-diamme
          dihydrochlonde in a mixture of 100 ml cone phosphoric acid and 800 ml of distilled
          water and dilute to 1 liter with distilled water
     6 7   Zmc sulfate solution Dissolve 100 g ZnSO47H2O in distilled water and dilute to 1 liter
     6 8   Sodium hydroxide solution, 6N Dissolve 240 g NaOH in 500 ml distilled water, cool and
          dilute to 1 liter
     6 9   Ammonium hydroxide, cone
     6 10  Dilute hydrochloric acid, 6N Dilute 50 rnl of cone HC1 to 100 ml with distilled water
     6 11  Copper sulfate solution, 2% Dissolve 20 g of CuSO45H2O in 500 ml of distilled water
          and dilute to 1 liter
     6 12  Stock nitrate solution Dissolve 7 218 g KNO3 in distilled water and dilute  to 1000 ml
          Preserve with 2 ml of chloroform per liter This solution is stable for at least 6 months
          10ml= 100mgNO3-N
                                         353 3-2

-------
10cm
       80-85 ml
                   3cm I D
               3 5 mm I D.
               GLASS WOOL PLUG
FIGURE  1. REDUCTION COLUMN
          353 3-3

-------
  6.13  Standard nitrate solution Dilute 10 0 ml of nitrate stock solution (6 12) to 1000 ml with
       distilled water 1 0 ml = 0 01 mg NO3-N
  6.14  Stock nitrite solution Dissolve 6 072 g KNO2 in 500 ml of distilled water and dilute to
       1000 ml Preserve with 2 ml of chloroform and keep under refrigeration  Stable for
       approximately 3 months 1 0 ml = 1 00 mg NO2-N
  6 15  Standard nitrite solution Dilute 10 0 ml of stock mtnte solution (6 14) to 1000 ml with
       distilled water 1 0 ml = 0 01 mg NO2-N
  6 16  Using standard nitrate solution (6 13) prepare the following standards  in  100 ml
       volumetric flasks

              Cone, mg-N03-N/l                    ml of Standard  Solution/1000 ml

                  000                                           00
                  005                                           05
                  010                                           10
                  020                                           20
                  050                                           50
                  100                                          100

 Procedure
 7 1   Turbidity removal One of the following methods may be used to remove  suspended
      matter
      7 1 1 Filter sample through a glass fiber filter or a 0 45u membrane filter
      7 1.2 Add 1 ml zinc sulfate solution (6 7) to 100 ml of sample and mix thoroughly Add
           0 4-0 5 ml sodium hydroxide solution (6 8) to obtain a pH of 10 5 as determined
           with a pH meter  Let the treated sample stand a few minutes to allow the heavy
           flocculent precipitate to settle Clarify by filtering through a glass fiber filter or a
           0 45 u membrane filter
 7 2   Oil and grease removal  Adjust the pH of 100 ml of filtered sample to 2 by addition of
      cone HC1 Extract the oil and grease from the aqueous solution with two 25 ml portions
      of a non-polar solvent (Freon, chloroform or equivalent)
 7.3   If the pH of the sample is below 5 or above 9, adjust to between 5 and 9 with either cone
      HC1 or cone NH^OH This is done to insure a sample pH of 8 5 after step 7 4
 7.4   To 25 0 ml of sample or an aliquot diluted to 25 0 ml, add 75 ml of ammonium chlonde-
      EDTA solution (6 4) and mix
 7.5   Pour sample into column and collect sample at a rate of 7-10 ml per minute
 7 6   Discard the first 25 ml, collect the rest of the sample (approximately 70 ml) in  the
      original sample flask  Reduced samples should not be allowed to stand longer than 15
     minutes before addition of color reagent, step 7 7
7 7  Add 2 0 ml of color reagent (6 6) to 50 0 ml of sample  Allow 10 minutes for color
     development Within 2 hours measure the absorbance at 540 nm against a reagent blank
     NOTE: If the concentration of sample exceeds 1 0 mg NO3-N/1, the remainder of the
     reduced sample may be used to make an appropriate dilution before proceeding with step
                                    353 3-4

-------
     7 8  Standards Carry out the reduction of standards exactly as described for the samples At
          least one nitrite standard should be compared to a reduced nitrate standard at the same
          concentration to verify the efficiency of the reduction column
     Calculation
     8 1  Obtain a standard curve by plotting the absorbance of standards run by  the above
          procedure against  NO3-N mg/1  Compute concentration of samples by comparing
          sample absorbance with standard curve
     82  If less than 25 ml of sample is used for the analysis the following equation should be used
                                rngNO, + N03 - N/l =
                                                      ml
          where
          A = Concentration of nitrate from standard curve
9    Precision and Accuracy
     91  In a single laboratory (EMSL), using sewage samples at concentrations of 0 04,0 24,0 55
          and 1 04 mg NO3 + NO2-N/1, the standard deviations were 0 005,  0 004, 0 005
          and _0 01, respectively
     92  In a single laboratory (EMSL), using sewage samples at concentrations of 0 24,0 55, and
          1 05 mg NO3 + NO2-N/1, the recoveries were 100%, 102% and 100%, respectively

                                      Bibliography

1    Standard Methods for the  Examination of Water and  Wastewater,  14th  Edition, p 423,
     Method 419C (1975)
2    Hennkson, A , and Selmer-Olsen, "Automatic Methods for Determining Nitrate and Nitrite in
     Water and Soil Extracts" Analyst, May 1970, Vol 95,p514-518
3    Grasshoff, K ,  "A Simultaneous Multiple Channel System for Nutrient Analysis in Sea Water
     with Analog and Digital Data Record",  "Advances in Automated Analysis", Techmcon
     International Congress, 1969, Vol  11, p 133-145
4    Brewer, P G, Riley, J P , "The Automatic Determination of Nitrate in Sea Water", Deep Sea
     Research, 1965, Vol 12, p 765-772
                                         353 3-5

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                               NITROGEN, NITRITE

                         Method 354.1  (Spectrophotometric)

                                                          STORET NO.  Total  00615

 1     Scope and Application
      1 1   This method is applicable to the determination of nitrite in drinking, surface and saline
           waters, domestic and industrial wastes
      1 2   The method is applicable in the range from 0 01 to 1 0 mg NO2-N/1
 2     Summary of Method
      2 1   The diazonmm compound formed by diazotation of sulfamlamide by nitrite in water
           under acid conditions is coupled with N-(l-naphthyl)-ethylenediamme dihydrochlonde
           to produce a reddish-purple color which is read in a spectrophotometer at 540 nm
 3     Sample Handling and Preservation
      3 1   Samples should be analyzed as soon as possible They may be stored for 24 to 48 hours at
           4C
4     Interferences
      4 1   There are very few known interferences at concentrations  less than 1,000 times that of
           the nitrite, however, the presence of strong oxidants or reductants in the samples will
           readily affect the  nitrite concentrations High alkalinity  (>600 mg/1) will give low
           results due to a shift in pH
5     Apparatus
      5 1   Spectrophotometer equipped with 1 cm or larger cells for use at 540 nm
      5 2   Nessler tubes, 50 ml or volumetric flasks, 50 rnl
6     Reagents
      6 1   Distilled water free of nitrite and nitrate is to be used in preparation of all reagents and
           standards
      6 2   Buffer-color reagent  To 250 ml of distilled water, add 105 ml cone hydrochloric acid,
           5 0 g sulfamlamide and 0 5 g N-(l-naphthyl) ethylenediamme dihydrochlonde Stir until
           dissolved   Add  136  g  of sodium acetate (CH3COONa3H2O) and again stir  until
           dissolved  Dilute to 500 ml with distilled water This solution is stable for several weeks if
           stored in the dark
      6 3   Nitrite stock solution 1 0 ml = 0  10 mg NO2-N Dissolve 0 1493 g of dried anhydrous
           sodium nitrite (24 hours in desiccator) in distilled water and dilute to 1000 ml Preserve
           with 2 ml chloroform per liter
      6 4   Nitrite standard solution 1 0 ml  = 0 001 mg NO2-N Dilute 10 0 ml of the stock
           solution (6 3) to 1000 ml
7     Procedure
      71    If the sample has a pH greater than 10 or a total alkalinity in excess of 600 mg/1, adjust
           to approximately pH 6 with 1 3 HC1

Approved for NPDES
Issued 1971

                                         354 1-1

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      7.2  If necessary, filter the sample through a 0 45 u pore size filter using the first portion of
           filtrate to rinse the filter flask
      7 3  Place 50 ml of sample, or an aliquot diluted to 50 ml, in a 50 ml Nessler tube, hold until
           preparation of standards is completed
      74  At the same time prepare a series of standards in 50 ml Nessler tubes as follows


                 ml of Standard Solution                        Cone, When Diluted to
                10 ml = 0001 mgNO2-N                     50 ml, mg/1 of NO2-N

                        0 0                                         (Blank)
                        05                                          001
                         10                                          002
                         15                                          003
                        20                                          004
                        30                                          006
                        40                                          008
                        50                                          010
                       10 0                                          0 20

      7 5  Add 2 ml of buffer-color reagent (6 2) to each standard and sample, mix and allow color
           to develop for at least 15 minutes The color reaction medium should be between pH 1 5
           and 20
      7.6  Read the  color in  the spectrophotometer at  540 nm against the blank and plot
           concentration of NO2-N against absorbance
8.    Calculation
      8 1   Read the concentration of NO2-N directly from the curve
      8 2   If less than 50 0 ml of sample is taken, calculate mg/1 as follows
                          Mr    M   /!   mg/1 from std  curve x 50
                          N02 - N, mg/1 = 	mlsampleused	


9    Precision and Accuracy
     9 1   Precision and Accuracy data are not available at this time


                                       Bibliography


1    Standard Methods for the Examination for Water and Wastewater, 14th Edition, p 434,
     Method 420, (1975)
                                          354 1-2

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                              OXYGEN, DISSOLVED

                        Method 360.1 (Membrane  Electrode)

                                                                 STORET NO. 00299

1    Scope and Application
     1 1  The probe method for dissolved oxygen is lecommended for those samples containing
          materials which  interfere  with the modified  Wmkler  procedure such as  sulfite,
          thiosulfate, polythionate, mercaptans, free chlorine or hypochlonte, organic substances
          readily hydrolyzed in alkaline solutions, free iodine,  intense color or turbidity and
          biological floes
     1 2  The probe method is recommended as a substitute for the modified Wmkler procedure in
          monitoring of streams, lakes, outfalls, etc, where it is desired to obtain a continuous
          record of the dissolved oxygen content of the water under observation
     1 3  The probe method may be used as a substitute for the modified Wmkler procedure in
          BOD determinations where it is desired to perform nondestructive DO measurements on
          a sample
     1 4  The probe method may be used under any circumstances as a substitute for the modified
          Wmkler procedure provided that the probe itself is standardized against the Wmkler
          method on samples free of interfering materials
     1 5  The electronic readout meter for the output from dissolved oxygen probes is normally
          calibrated in convenient scale (0 to 10, 0 to 15, 0 to 20 mg/1 for example) with a
          sensitivity of approximately 0 05 mg/hter
2    Summary of Method
     2 1  The most common instrumental probes for determination of dissolved oxygen in water
          are  dependent upon electrochemical  reactions  Under  steady-state conditions,  the
          current or potential can be correlated with DO concentrations Interfacial dynamics at
          the probe-sample interface are a factor in probe response and a significant degree of
          mterfacial turbulence is necessary For precision performance, turbulence should be
          constant
3    Sample Handling and Preservation
     31  See 4 1,4 2,4 3,4 4 under Modified Wmkler Method (360 2)
4    Interferences
     4 1  Dissolved organic materials are not known to interfere in the output from  dissolved
          oxygen probes
     4 2  Dissolved inorganic salts are a factor in the performance of dissolved oxygen probe
          421 Probes with membranes respond to  partial pressure of oxygen which in turn is a
                function of dissolved inorganic salts  Conversion factors for seawater and brackish
                waters may be calculated from dissolved oxygen saturation versus salinity data
                Conversion factors for specific inorganic salts may be developed experimentally

Approved for NPDES
Issued 1971

                                         360 1-1

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                Broad variations in the kinds and concentrations of salts in samples can make the
                use of a membrane probe difficult
     4 3   Reactive compounds can interfere with the output or the performance of dissolved
           oxygen probes
           431 Reactive gases which pass through the membrane probes  may interfere  For
                example, chlorine will depolarize the  cathode and cause a high probe-output
                Long-term exposures to chlorine will coat the anode with the chloride of the anode
                metal and eventually desensitize the probe Alkaline samples in which free chlorine
                does not exist will not interfere  Hydrogen sulfide will interfere with membrane
                probes if the applied potential is greater than the half-wave potential of the sulfide
                ion If the applied potential is less than the half-wave potential, an interfering
                reaction will not occur, but coating of the anode with the sulfide of the anode metal
                can take place
     4 4   Dissolved oxygen  probes are temperature sensitive, and temperature compensation is
           normally provided  by the  manufacturer   Membrane  probes have  a  temperature
           coefficient of 4 to 6 percent/C dependent upon the membrane employed
5    Apparatus
     5 1   No specific probe or accessory is especially recommended as superior However, probes
           which have been evaluated or are in use and found to be reliable are the Weston & Stack
           DO Analyzer Model  30, the Yellow  Springs Instrument (YSI) Model 54,  and the
           Beckman Fieldlab Oxygen Analyzer
6,    Calibration
     Follow manufacturer instructions
7.    Procedure
     Follow manufacturer instructions
8.    Calculation
     Follow manufacturer instructions
9.    Precision and Accuracy
     Manufacturer's specification claim 0 1 mg/1 repeatability with   1 % accuracy

                                      Bibliography

1    Standard  Methods  for the Examination of  Watef and  Wastewater, 14th Edition, p 450,
     Method 422F (1975)
                                         360 1-2

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                               OXYGEN, DISSOLVED

             Method 360.2  (Modified Winkler, Full-Bottle Technique)

                                                                 STORET NO. 00300

      Scope and Application
      1 1   This method is applicable for use with most wastewaters and streams that contain nitrate
           nitrogen and not more than 1 mg/1 of ferrous iron Other reducing of oxidizing materials
           should be absent If 1 ml of fluoride solution is added before acidifying the sample and
           there is no delay in titration, the method is also applicable in the presence of 100-200
           mg/1 ferric iron
      1 2   The Dissolved Oxygen (DO) Probe technique gives comparable results on all samples
           types
      1 3   The azide modification is not applicable under the following conditions  (a) samples
           containing sulfite, thiosulfate, polythionate, appreciable quantities of free chlorine or
           hypochlonte,  (b) samples  high in suspended solids,  (c) samples containing  organic
           substances which are readily oxidized in a highly alkaline solution, or which are oxidized
           by free iodine in an acid solution, (d) untreated domestic sewage, (e) biological floes, and
           (f) where sample color interferes with endpomt detection  In instances where the azide
           modification is not applicable, the DO probe should be used
      Summary of Method
      2 1   The sample is treated with manganous sulfate, potassium hydroxide, and potassium
           iodide (the latter two reagents combined in one solution) and finally sulfunc acid The
           initial precipitate of manganous  hydroxide, Mn(OH)2,  combines with the dissolved
           oxygen in the sample to form a brown  precipitate, manganic hydroxide,  MnO(OH)2
           Upon acidification, the manganic hydroxide forms manganic  sulfate which acts as an
           oxidizing agent to release free iodine from the potassium iodide The iodine, which is
           stoichiometncally equivalent to the dissolved oxygen in the sample is then titrated with
           sodium thiosulfate or phenylarsme oxide (PAO)
      Interferences
      3 1   There are a number of interferences to the dissolved oxygen test, including oxidizing and
           reducing agents, nitrate ion, ferrous iron, and organic matter
      3 2   Various modifications of the original Wmkler procedure for dissolved oxygen have been
           developed to compensate for or eliminate interferences The Alsterberg modification is
           commonly used to successfully eliminate the nitrite interference, the Rideal-Stewart
           modification is designed to eliminate ferrous  iron interference, and the  Thenault
           procedure is used to compensate for high concentration of organic materials
      3 3   Most of the common interferences in the Winkler procedure may be overcome by use of
           the dissolved oxygen probe
Approved for NPDES
Issued 1971

                                          360 2-1

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4.   Sample Handling and Preservation
     4 1   Where possible,  collect the sample  in  a 300 ml BOD incubation bottle  Special
           precautions are required to avoid entramment or solution of atmospheric oxygen or loss
           of dissolved oxygen
     4 2   Where samples are collected from shallow depths (less than 5 feet), use of an APHA-type
           sampler is recommended Use of a Kemmerer type sampler is recommended for samples
           collected from depths of greater than 5 feet
     4 3   When a  Kemmerer sampler  is used, the  BOD  sample bottle should be  filled to
           overflowing (overflow for approximately 10 seconds) Outlet tube of Kemmerer should
           be inserted to bottom of BOD bottle Care must be taken to prevent turbulence and the
           formation of bubbles when filling bottle
     4.4   At time of sampling, the sample temperature should be recorded as precisely as required
     4.5   Do not delay the determination of dissolved oxygen in samples having an appreciable
           iodine demand or containing ferrous iron If samples must be preserved either method
           (4 5 1) or (4 5 2) below, may be employed
           4.5 1 Add 2 ml of manganous sulfate solution (6 1) and then 2 ml of alkaline lodide-azide
                solution (6 2) to the sample contained in the BOD bottle Both reagents must be
                added well below the surface of the liquid Stopper the bottle immediately and mix
                the contents thoroughly The sample should be stored at the temperature of the
                collection water, or water sealed and kept at  a temperature of 10 to 20C, in the
                dark Complete the procedure by adding 2 ml H2SO4 (see 7 1) at time of analysis
           4.5 2 Add 0 7 ml of cone H2SO4 (6 3)  and 1 ml sodium azide solution (2 g NaN3 in 100
                ml  distilled water) to sample in the  BOD bottle  Store  sample as  in (4 5 1)
                Complete the procedure using 2 ml of manganous sulfate solution (6  1), 3 ml
                alkaline lodide-azide solution (6 2), and 2 ml of cone  H2SO4  (6 3)  at time of
                analysis
     4 6   If either preservation technique is employed, complete the analysis within 4-8 hours after
           sampling
5.   Apparatus
     5 1   Sample bottles-300 ml  3  ml capacity BOD incubation bottles with tapered ground
           glass pointed stoppers and flared mouths
     5.2   Pipets-with elongated tips capable of delivering 2 0 ml 0 10 ml of reagent
6   Reagents
     6 1   Manganous sulfate solution Dissolve 480 g manganous sulfate (MnSO44H2O in distilled
           water and dilute to 1 liter
           6 1 1 Alternatively, use 400 g of MnSO42H2O or 364 g of MnSO4H2O per liter When
                uncertainty exists regarding the  water  of crystallization,  a solution of equivalent
                strength may be obtained by adjusting the specific gravity of the solution to 1 270
                at20C
     6 2   Alkaline lodide-azide solution  Dissolve 500 g of sodium hydroxide (NaOH) or 700 g of
           potassium hydroxide (KOH) and 135  g of sodium  iodide (Nal) or 150 g of potassium
           iodide (KI) in distilled water and dilute to 1  liter To this solution add 10 g of solution
           azide (NaN3) dissolved in 40 ml of distilled water
                                         360 2-2

-------
     6 3   Sulfuric acid concentrated
     6 4   Starch solution  Prepare an emulsion of 10 g soluble starch in a mortar or beaker with a
           small quantity of distilled water Pour this emulsion into 1 liter of boiling water, allow to
           boil a few minutes, and let settle overnight Use the clear supernate This solution may be
           preserved  by the addition of 5 ml  per liter  of chloroform and storage in  a  10C
           refrigerator
           641 Dry, powdered starch indicators such as "thyodene" may be used m place of starch
                solution
     6 5   Potassium fluoride solution Dissolve 40 g KF2H2O in distilled water and dilute to 100
           ml
     6 6   Sodium thiosulfate,  stock solution, 0 75 N Dissolve 186 15 g Na2S2O35H2O in boiled
           and cooled distilled water and dilute to 1 liter Preserve by adding 5 ml chloroform
     6 7   Sodium thiosulfate  standard titrant,  0 0375 N  Prepare by diluting 50 0 ml of stock
           solution to 1 liter Preserve by adding 5  ml of chloroform  Standard sodium thiosulfate,
           exactly 0 0375 N is equivalent to 0 300 mg of DO per 1 00 ml Standardize with 0 0375 N
           potassium bnodate
     6 8   Potassium bnodate standard, 0 0375 N For stock solution, dissolve 4 873 g of potassium
           bnodate, previously  dried 2 hours at 103C, in 1000 ml of distilled water To prepare
           working standard, dilute 250 ml to 1000 ml for 0 0375 N bnodate solution
     6 9   Standardization of 0 0375 N sodium thiosulfate Dissolve approximately 2 g ( 1 0 g) KI
           in 100 to 150 ml distilled water, add 10 ml of 10% H2SO4 followed by 20 0 ml standard
           potassium bnodate (6 8) Place in dark for 5 minutes, dilute to 300 ml,  and titrate with
           the standard sodium thiosulfate (6 7) to a pale straw color Add 1-2 ml starch solution
           and continue the titration drop by drop until the blue color disappears Run m duplicate
           Duplicate determinations should agree within +0 05 ml
     6 10  As an alternative to the sodium thiosulfate, phenylarsine oxide (PAO) may be used This
           is available, already standardized, from commercial sources
7    Procedure
     71   To the sample collected in the BOD incubation bottle, add 2 ml of the manganous sulfate
           solution (61) followed by 2 ml of the alkaline lodide-azide solution (6 2), well below the
           surface of the liquid, stopper with care to exclude air bubbles, and mix well by inverting
           the bottle several times When the precipitate settles, leaving a clear supernatant above
           the manganese hydroxide floe, shake again When settling has produced at least 200 ml
           of clear supernatant, carefully remove the stopper and immediately add 2 ml of cone
           H2SO4 (6 3) (sulfamic acid packets, 3 g may be substituted for H2SO4)C1) by allowing the
           acid to run down the neck of the bottle, re-stopper, and mix by gentle inversion until the
           iodine is uniformly distributed throughout the bottle Complete the analysis within 45
           minutes
     7 2   Transfer the entire bottle contents by inversion into a 500 ml wide mouth flask and titrate
           with 0 0375  N thiosulfate solution (6 7) (0 0375 N phenyarsme oxide (PAO) may be
           substituted as titrant) to pale straw color Add 1-2 ml of starch solution (6 4) or 0 1 g of
           powdered indicator and continue to titrate to the first disappearance of the blue color
                                          360 2-3

-------
      73   If feme iron is present (100 to 200 mg/1), add  1 0 ml of KF (6 5) solution before
           acidification
      7 4   Occasionally, a dark brown or black precipitate persists in the bottle after acidication
           This precipitate will dissolve if the solution is kept for a few minutes longer than usual or,
           if particularly persistent, a few more drops of H2SO4 will effect dissolution
8.    Calculation
      8.1   Each ml of 0 0375N sodium thiosulfate (or PAO) titrant is equivalent to 1 mg DO when
           the entire bottle contents are titrated
      82   If the results are desired in milhhters of oxygen gas per liter at 0C and 760 mm pressure
           multiply mg/1 DObyO 698
      83   To express the results as percent saturation at 760 mm atmospheric pressure, the
           solubility data m Table 422 1 (Whipple & Whipple, p 446-447, Standard Methods, 14th
           Edition) may be used  Equations for correcting the solubilities to barometric pressures
           other than mean sea level are given below the table
      8 4   The  solubility of DO in  distilled water at any  barometric  pressure, p (mm  Hg),
           temperature, TC, and saturated vapor pressure, u (mm Hg), for the given T,  may be
           calculated between the temperature of 0 and 30C by
                                      ml/1 DO =
                                                     35 + T
           and between 30 and 50C by
                                     ml/! DO-  (P "4}+XT 82?

9    Precision and Accuracy
     9 1   Exact data are unavailable on the precision and accuracy of this technique, however,
           reproducibihty is approximately 0 2 mg/1 of DO at the 7 5 mg/1 level due to equipment
           tolerances and uncompensated displacement errors

                                       Bibliography

1    Kroner, R  C,  Longbottom, J  E, Gorman, R A ,  "A  Comparison of Various  Reagents
     Proposed for Use m the Winkler Procedure for Dissolved Oxygen", PHS Water  Pollution
     Surveillance System Applications and  Development, Report #12,  Water Quality Section,
     Basic Data Branch, July 1964
2.    Annual Book of ASTM Standards, Part 31, "Water", Standard D1589-60, Method A, p 373
     (1976)
3,    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 443, method
     422B(1975)
                                          360 2-4

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                         PHOSPHORUS, ALL  FORMS

             Method 365.1  (Colorimetric,  Automated, Ascorbic Acid)

                                                      STORET NO. See Section 4

     Scope and Application
     1 1   These methods cover the determination of specified forms of phosphorus in drinking,
          surface and saline waters, domestic and industrial wastes
     1 2   The methods are based on reactions that are specific for the orthophosphate ion Thus,
          depending  on  the prescribed pre-treatment  of  the  sample,  the  various forms  of
          phosphorus given in Figure 1 may be determined These forms are defined in Section 4
           121 Except for in-depth and detailed studies, the most commonly measured forms are
               phosphorus  and  dissolved  phosphorus, and  orthophosphate  and dissolved
               orthophosphate Hydrolyzable phosphorus is normally found only in sewage-type
               samples Insoluble forms of phosphorus are determined by calculation
     1 3   The methods are usable in the 0 01 to 1 0 mg P/l range Approximately 20-30 samples
          per hour can be analyzed
     Summary of Method
     2 1   Ammonium molybdate and antimony potassium tartrate react in an acid medium with
          dilute solutions of phosphorus to form an antimony-phospho-molybdate complex This
          complex is reduced to an intensely blue-colored complex by ascorbic acid The color is
          proportional to the phosphorus concentration
     2 2   Only orthophosphate forms a blue color in this test Polyphosphates (and some organic
          phosphorus compounds) may be converted to the orthophosphate form by  manual
          sulfunc acid hydrolysis  Organic  phosphorus  compounds may be converted  to  the
          orthophosphate form by manual persulfate digestion The developed color is measured
          automatically on the AutoAnalyzer
     Sample Handling and Preservation
     3 1   If benthic deposits are present in the area being sampled, great care should be taken not
          to include these deposits
     3 2   Sample containers  may be of plastic material, such as cubitamers,  or of Pyrex glass
     33   If the analysis cannot be performed the same day of collection, the sample should be
          preserved by the addition of 2 ml cone  H2SO4 per liter and refrigeration at 4C
     Definitions and Storet Numbers
     4 1   Total Phosphorus (P) - all of the phosphorus present in the sample regardless of form, as
          measured by the persulfate digestion procedure (00665)
          411 Total Orthophosphate (P-ortho)-morgamc phosphorus [(PO4X3] in the sample as
               measured by the direct colonmetric analysis procedure (70507)
Approved for NPDES, pending approval for Section 304(h), CWA
Issued 1971
Editorial revision 1974 and 1978

                                        365 1-1

-------
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                                 365  1-2

-------
     4 1 2 Total Hydrolyzable Phosphorus (P-hydro)-phosphorus in the sample as measured
          by   the   sulfunc  acid  hydrolysis   procedure,  and   minus  predetermined
          orthophosphates   This  hydrolyzable  phosphorus  includes  polyphosphates
          [(P2O7)'4, (P3O10)~5, etc ] plus some organic phosphorus  (00669)
     413 Total Organic Phosphorus (P-org)-phosphorus (inorganic plus oxidizable organic)
          in the sample as  measured by the persulfate digestion procedure,  and minus
          hydrolyzable phosphorus and orthophosphate (00670)
4 2  Dissolved Phosphorus (P-D) - all of the phosphorus present m the filtrate of a sample
     filtered through a phosphorus-free filter of 0 45 micron pore size and measured by the
     persulfate digestion procedure (00666)
     4 2 1 Dissolved Orthophosphate (P-D, ortho) - as measured by the direct colonmetnc
          analysis procedure (00671)
     422 Dissolved Hydrolyzable Phosphorus (P-D, hydro) - as measured by the sulfuric
          acid hydrolysis procedure and minus  predetermined dissolved orthophosphates
          (00672)
     423 Dissolved Organic Phosphorus  (P-D,  org) - as  measured by the persulfate
          digestion  procedure,  and  minus dissolved  hydrolyzable  phosphorus   and
          orthophosphate (00673)
4 3  The following forms, when sufficient amounts of phosphorus are present in the sample to
     warrant such consideration, may be calculated
     43 1 Insoluble Phosphorus (P-I)=(P)-(P-D) (00667)
          4311    Insoluble orthophosphate  (P-I, ortho)=(P,  ortho) -  (P-D, ortho)
                     (00674)
          4312    Insoluble Hydrolyzable Phosphorus (P-I, hydro) = (P, hydro) - (P-
                     D, hydro) (00675)
          4313    Insoluble Organic Phosphorus (P-I, org) = (P, org)  - (P-D,  org)
                     (00676)
4 4   All phosphorus forms shall be reported as P, mg/1, to the third place
Interferences
51   No interference is caused by  copper, iron, or silicate at concentrations many times
      greater  than  their  reported concentration in sea  water   However,   high   iron
      concentrations can cause precipitation of and subsequent loss of phosphorus
5 2   The salt error for samples ranging from 5 to 20% salt content was found to be  less than
      1%
5 3   Arsenate is determined  similarly to phosphorus and should be considered when present
      in concentrations  higher  than phosphorus  However, at concentrations found in sea
      water, it does not interfere
5 4   Sample turbidity must  be removed by filtration prior to analysis for orthophosphate
      Samples  for total or total hydrolyzable phosphorus  should be filtered only  after
      digestion Sample  color that absorbs in the photometric range used for analysis will also
      interfere
Apparatus
6 1   Techmcon Auto Analyzer consisting of
                                     365 1-3

-------
      611 Sampler
      6 1 2 Manifold (AAI) or Analytical Cartridge (AAII)
      613 Proportioning pump
      614 Heating bath, 50C
      6.1 5 Colorimeter equipped with 15 or 50 mm tubular flow cell
      616 650-660 or 880 nm filter
      617 Recorder
      6 1 8 Digital printer for AAII (optional)
 6 2   Hot plate or autoclave
 6.3   Acid-washed glassware All glassware used in the determination should be washed with
      hot 1 1 HC1 and rinsed with distilled water The acid-washed glassware should be filled
      with distilled water and treated with all the reagents  to  remove the last  traces of
      phosphorus that might be adsorbed on the glassware Preferably, this glassware should
      be used only for the determination of phosphorus and after use it should be rinsed with
      distilled water and kept covered until needed again If this is done, the treatment with 1 1
      HC1 and reagents is only  required occasionally Commercial detergent should never be
      used
 Reagents
 7 1   Sulfuric acid solution,  5N Slowly add 70 ml of cone  H2SO4 to approximately 400 ml of
      distilled water Cool to room temperature and dilute to 500 ml with distilled water
 7 2   Antimony potassium tartrate solution Weigh 0 3 g K(SbO)C4H4O6l/2H2O, dissolve in
      50 ml distilled water in 100 ml volumetric flask, dilute to volume Store at 4C in a dark,
      glass-stoppered bottle
 7 3   Ammonium molybdate solution Dissolve 4 g (NH4)6Mo7O244H2O in 100 ml distilled
      water Store in a plastic bottle at 4C
 7 4   Ascorbic acid, 0 1M  Dissolve  1 8 g of ascorbic acid in 100 ml of distilled water  The
      solution is stable for about a week if prepared  with water containing no more than trace
      amounts of heavy metals and stored at 4C
 7.5   Combined reagent (AAI)  Mix the above reagents in the following proportions for 100 ml
      of the mixed reagent  50  ml of 5N H2SO4 (7 1), 5 ml of antimony potassium tartrate
      solution (7 2), 15 ml of ammonium molybdate solution (7 3),  and 30 ml of ascorbic acid
      solution (7 4)  Mix after addition  of each reagent All reagents must reach room
      temperature before they are mixed and must be mixed in the order given If turbidity
      forms in the combined reagent,  shake and let stand for a few minutes until the turbidity
      disappears before processing  This volume is sufficient for 4 hours operation  Since the
      stability of this solution is limited, it must be freshly prepared for each run,
      NOTE 1: A stable  solution can be prepared by not including the ascorbic acid in the
      combined reagent  If this  is done, the mixed reagent (molybdate, tartrate, and acid) is
      pumped through the distilled water line and the ascorbic acid solution (30 ml of 7 4
      diluted to 100 ml with distilled water) through the original mixed reagent line
7 6   Sulfuric acid solution,  11 N Slowly add 310 ml cone H2SO4 to 600 ml  distilled water
      When cool, dilute to 1 liter
                                     365 1-4

-------
7 7  Ammonium persulfate
7 8  Acid wash water Add 40 ml of sulfuric acid solution (7 6) to 1 liter of distilled water and
     dilute to 2 liters (Not to be used when only orthophosphate is being determined)
7 9  Phenolphthalem indicator  solution (5 g/1) Dissolve 0 5 g of phenolphthalem in  a
     solution of 50 ml of ethyl or isopropyl alcohol and 50 ml of distilled water
7 10 Stock phosphorus solution Dissolve 0 4393 g of pre-dned (105C for 1 hour) KH2PO4 m
     distilled water and dilute to 1000 ml  1 0 ml = 0 1 mg P
7 11 Standard phosphorus solution Dilute 100 0 ml of stock solution (7 10) to 1000 ml with
     distilled water 1 0 ml = 0 01 mg P
7 12 Standard phosphorus solution Dilute 100 0 ml of standard solution (7 11) to 1000 ml
     with distilled water 1 0 ml = 0 001 mg P
713 Prepare a series of standards by diluting suitable volumes of standard solutions (7 11)
     and (7 12) to 100 0 ml with distilled water The following dilutions are suggested

               ml of Standard                                    Cone ,
          Phosphorus Solution (7  12)                               mg P/l
                   00                                           000
                   20                                           002
                   50                                           005
                  100                                           010

               ml of Standard
          Phosphorus Solution (7 11)                              mg P/l
                   20                                           020
                   50                                           050
                   80                                           080
                  100                                           100

Procedure
8 1   Phosphorus
      811 Add 1 ml of sulfuric acid solution (7 6) to a 50 ml sample and/or standard m a 125
           ml Erlenmeyer flask
      812 Add 0 4 g of ammonium persulfate
      813 Boil gently on a pre-heated hot plate for approximately 30-40 minutes or until a
           final volume  of about 10 ml is reached Do not allow sample to go to dryness
           Alternately, heat for 30 minutes m an autoclave at 121C (15-20 psi)
      814 Cool and dilute the sample to 50 ml  If sample is not clear at this point, filter
      815 Determine phosphorus as outlined in (8 3 2) with acid wash water (7 8) m wash
           tubes
82   Hydrolyzable Phosphorus
      821 Add 1 ml of sulfuric acid solution (7 6) to a 50 ml sample and/or standard in a 125
           ml Erlenmeyer flask
                                     365 1-5

-------
           822 Boil gently on a pre-heated hot plate for 30-40 minutes or until a final volume of
                about 10 ml is reached  Do not allow sample to go to dryness Alternatively, heat
                for 30 minutes in an autoclave at 121C (15-20 psi)
           823 Cool and dilute the sample to 50 ml If sample is not clear at this point, filter
           824 Determine phosphorus  as outlined m (8 3 2) with acid wash water (7 8) in wash
                tubes
     8 3   Orthophosphate
           831 Add 1 drop of phenolphthalem indicator solution (7 9) to approximately 50 ml of
                sample If a red color develops, add sulfunc acid solution (7 6) drop-wise to just
                discharge the color Acid samples must be neutralized with 1 N sodium hydroxide
                (40gNaOH/l)
           832 Set up manifold as shown in Figure 2, AAI or Figure 3, AAII
           833 Allow both colorimeter and recorder to warm up for 30 minutes Obtain a stable
                baseline with all reagents, feeding distilled water through the sample line
           834 For the AAI system, sample at a rate of 20/hr, 1 minute sample, 2 minute wash
                For the AAII system, use a 30/hr, 2 1 cam, and a common wash
           835 Place standards in Sampler in order of decreasing concentration Complete filling
                of sampler tray with unknown samples
           836 Switch sample line from distilled water to Sampler and begin analysis
9    Calculation
     9 1   Prepare a standard curve by plotting peak heights of processed standards against known
           concentrations  Compute concentrations of samples by comparing sample peak heights
           with standard curve Any sample whose computed value is less than 5% of its immediate
           predecessor must be rerun
10   Precision and Accuracy (AAI system)
     10 1  Six laboratories  participating in an  EPA Method Study, analyzed four natural water
           samples containing exact increments of Orthophosphate, with the following results
      Increment as
     Orthophosphate
       rag P/liter

          004
          004
          029
          030
   Precision as
Standard Deviation
    mg P/liter

      0019
      0014
      0087
      0066
Accuracy as
Bias,
%
+ 167
- 83
-155
-128
Bias,
mg P/liter
+0007
-0003
-005
-004
     10 2 In a single laboratory (EMSL), using surface water samples at concentrations of 0 04,
          0 19, 035, and 0 84 mg P/l, standard deviations were 0005,  0000, 0003,  and
          Q 000, respectively
     10 3 In a single laboratory (EMSL), using surface water samples at concentrations of 0 07 and
          0 76 mg p/1, recoveries were 99% and 100%, respectively
                                         365 1-6

-------
                                     Bibliography

1    Murphy, J and Riley, J , "A Modified Single Solution for the Determination of Phosphate in
     Natural Waters" Anal China Acta ,27, 31 (1962)
2    Gales, M , Jr , Julian, E , and Kroner, R , "Method for Quantitative Determination of Total
     Phosphorus in Water" Jour AWWA, 58, No 10,1363(1966)
3    Lobrmg, L B and Booth, R L , "Evaluation of the AutoAnalyzer II; A Progress Report",
     Techmcon International Symposium, June, 1972 New York, N Y
4    Annual Book of ASTM Standards, Part 31, "Water", Standard D515-72, p 388 (1976)
5    Standard Methods for the Examination of Water and Wastewater,  14th Edition, p 624,
     Method 606, (1975)
                                         365 1-7

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-------
                         PHOSPHORUS, ALL  FORMS

          Method 365.2 (Colorimetric, Ascorbic Acid, Single Reagent)

                                                      STORET  NO. See Section 4

1    Scope and Application
     1 1   These methods cover the determination of specified forms of phosphorus m drinking,
          surface and saline waters, domestic and industrial wastes
     1 2   The methods are based on reactions that are specific for the orthophosphate ion  Thus,
          depending on  the prescribed pre-treatment  of the sample,  the various  forms of
          phosphorus given in Figure 1 may be determined These forms are defined in Section 4
          121 Except for in-depth and detailed studies, the most commonly measured forms are
               phosphorus  and  dissolved  phosphorus,  and  orthophosphate  and  dissolved
               orthophosphate Hydrolyzable phosphorus  is normally found only m sewage-type
               samples and insoluble forms of phosphorus are determined by calculation
     1 3   The methods are usable in the 0 01 to 0 5 mg P/l range
2    Summary of Method
     2 1   Ammonium molybdate and antimony potassium tartrate react in an acid medium with
          dilute solutions of phosphorus to form an antimony-phospho-molybdate complex This
          complex is reduced to an intensely blue-colored complex by ascorbic acid The color is
          proportional to the phosphorus concentration
     2 2  Only orthophosphate forms a blue color in this test Polyphosphates (and some organic
          phosphorus compounds) may be converted to the orthophosphate form by sulfunc acid
          hydrolysis Organic phosphorus compounds may be converted to the orthophosphate
          form by persulfate digestion
3    Sample Handling and Preservation
     31  If benthic deposits are present in the area being sampled, great care should be taken not
          to include these deposits
     3 2  Sample containers may be of plastic material, such as cubitamers, or of Pyrex glass
     33  If the analysis cannot be performed the day of collection, the sample should be preserved
          by the addition of 2 ml cone H2SO4 per liter and refrigeration at 4C
4    Definitions and Storet Numbers
     4 1  Total Phosphorus (P)  all of the phosphorus present in the sample, regardless of form,
          as measured by the persulfate digestion procedure (00665)
          4 1 1 Total Orthophosphate (P, ortho)  inorganic phosphorus [(PO4)"3] in the sample
                as measured by the direct colorimetnc analysis procedure (70507)
          412 Total  Hydrolyzable Phosphorus  (P, hydro)  - phosphorus in the  sample as
                measured by the sulfuric acid hydrolysis  procedure, and minus pre-determmed
                orthophosphates  This hydrolyzable  phosphorus  includes  polyphosphorus
                [(PsO?)"4, (P3O10)"5, etc ] plus some organic phosphorus (00669)

 Approved for NPDES
 Issued 1971

                                          365 2-1

-------





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-------
     413 Total Organic Phosphorus  (P, org)  phosphorus (inorganic plus oxidizable
          organic) in the sample measured by the persulfate digestion procedure, and minus
          hydrolyzable phosphorus and orthophosphate (00670)
4 2  Dissolved Phosphorus (P-D)  all of the phosphorus present in the filtrate of a sample
     filtered through a phosphorus-free filter of 0 45 micron pore size and measured by the
     persulfate digestion procedure (00666)
     421 Dissolved Orthophosphate (P-D, ortho)  as measured by the direct colonmetnc
          analysis procedure (00671)
     422 Dissolved Hydrolyzable Phosphorus (P-D, hydro)  as measured by the sulfunc
          acid hydrolysis procedure and minus pre-determmed dissolved orthophosphates
          (00672)
     423 Dissolved Organic Phosphorus (P-D, org)   as  measured by the persulfate
          digestion  procedure,  and  minus  dissolved  hydrolyzable phosphorus  and
          orthophosphate (00673)
4 3  The following forms, when sufficient amounts of phosphorus are present in the sample to
     warrant such consideration, may be calculated
     43 1 Insoluble Phosphorus (P-I)=(P)-(P-D) (00667)
          4311    Insoluble  orthophosphate  (P-I,  ortho)=(P,  ortho)-(P-D,  ortho)
                     (00674)
           4312    Insoluble  Hydrolyzable Phosphorus  (P-I, hydro)=(P, hydro)-(P-D,
                     hydro) (00675)
           4313    Insoluble  Organic  Phosphorus (P-I, org)=(P,  org) -  (P-D,  org)
                     (00676)
 4 4   All phosphorus forms shall be reported as P, mg/1, to the third place
 Interferences
 51   No interference is caused by copper, iron, or silicate at concentrations   many    times
      greater  than  their reported  concentration  in  sea water  However,  high  iron
      concentrations can cause precipitation of and subsequent loss of phosphorus
 5 2   The salt error for samples ranging from 5 to 20% salt content was found to be less than
      1%
 5 3   Arsenate is determined similarly to phosphorus and should be considered when present
      m concentrations higher than phosphorus However, at concentrations found in sea
      water, it does not interfere
 Apparatus
 6 1   Photometer - A spectrophotometer or filter photometer  suitable for measurements at
      650 or 880 nm with a light path of 1 cm or longer
 6 2   Acid-washed glassware All  glassware used should be washed with hot 1 1 HC1 and
      rinsed with distilled water The acid-washed glassware should be filled with  distilled
      water and treated with all the reagents to remove the last traces of phosphorus that might
      be adsorbed on the glassware  Preferably, this glassware should be used only for the
      determination of phosphorus and after use it should be rinsed with distilled water and
                                      365 2-3

-------
           kept covered until needed again  If this is done, the treatment with 1 1 HC1 and reagents
           is only required occasionally Commercial detergents should never be used
7.    Reagents
     7 1   Sulfunc acid solution, 5N Dilute 70 ml of cone H2SO4 with distilled water to 500 ml
     7 2   Antimony potassium tartrate  solution  Weigh 1 3715  g K(SbO)C4H4O6l/2H2O,
           dissolve in 400 ml distilled water in 500 ml volumetric flask, dilute to volume Store at
           4C m a dark, glass-stoppered bottle
     7 3   Ammonium molybdate solution  Dissolve 20 g(NH4)6Mo7O244H2O in 500 ml of distilled
           water  Store m a plastic bottle at 4C
     7 4   Ascorbic acid, 0 LM Dissolve 1  76 g of ascorbic acid in 100 ml of distilled water The
           solution is stable for about a week if stored at 4C
     7 5   Combined reagent Mix the above reagents in the following proportions for 100 ml of the
           mixed reagent  50 ml of 5N H2SO4) (7 1), 5 ml of antimony potassium tartrate solution
           (7 2), 15 ml of ammonium molybdate solution (7 3), and 30 ml of ascorbic acid solution
           (7 4)  Mix after addition of each reagent  All reagents must reach room temperature
           before they are mixed and must  be mixed  m the order given If turbidity forms m the
           combined reagent, shake and let  stand for  a few minutes until the turbidity disappears
           before proceeding Since the stability of this solution is  limited, it must be freshly
           prepared for each run
     7 6   Sulfunc acid solution, 11 N Slowly add 310 ml cone H2SO4 to 600 ml distilled water
           When cool, dilute to 1 liter
     7 7   Ammonium persulfate
     7 8  Stock phosphorus solution Dissolve in distilled water 0 2197 g of potassium dihydrogen
          phosphate, KH2PO4, which has been dried in an oven at 105C  Dilute the solution to
           1000ml, 1 Oml = 005 mgP
     7 9   Standard phosphorus solution Dilute 10 0 ml of stock phosphorus solution (7 8) to 1000
          ml with distilled water, 1 0 ml = 0 5 ug P
          791 Using standard solution, prepare the following standards in 50 0 ml volumetric
               flasks

                   ml  of Standard
               Phosphorus Solution (79)                              Cone, mg/1

                         0                                            000
                       10                                            001
                       30                                            003
                       50                                            005
                      100                                            010
                      20 0                                            0 20
                      30 0                                            0 30
                      40 0                                            0 40
                      50 0                                            0 50

    7 10 Sodium hydroxide, 1 N Dissolve 40 g NaOH in 600 ml distilled water Cool and dilute
         to 1 liter
                                         365 2-4

-------
Procedure
8 1   Phosphorus
     8 1 1 Add 1 ml of H2SO4 solution (7 6) to a 50 ml sample in a 125 ml Erlenmeyer flask
     812 Add 0 4 g of ammonium persulfate
     8 1 3 Boil gently on a pre-heated hot plate for approximately 30-40 minutes or until a
          final volume  of about 10 ml is reached Do not allow sample to go to dryness
          Alternatively, heat for 30 minutes in an autoclave at 121C (15-20 psi)
     8 1 4 Cool and dilute the sample to about 30 ml and adjust the pH of the sample to 7 0
          +0 2 with 1 N NaOH (7 10) using a pH meter If sample is not clear at this point,
          add 2-3 drops of acid (7 6) and filter Dilute to 50 ml
          Alternatively, if autoclaved see NOTE 1
     8 1 5 Determine phosphorus as outlined in 8 3 2 Orthophosphate
8 2  Hydrolyzable Phosphorus
     8 2 1 Add 1 ml of H2SO4 solution (7 6) to a 50 ml sample in a 125 ml Erlenmeyer flask
     822 Boil gently on a pre-heated hot plate for 30-40 minutes or until a final volume of
          about 10 ml is reached Do not allow  sample to go to dryness  Alternatively, heat
          for 30 minutes in an autoclave at 121C (15-20 psi)
     823 Cool and dilute the sample to about 30 ml and adjust the pH of the sample to 7 0
           0 2 with NaOH (7 10) using a pH meter If sample is not clear at this point, add
          2-3 drops of acid (7 6) and filter Dilute to 50 ml
          Alternatively, if autoclaved see NOTE 1
      824 The sample is now ready for determination of phosphorus as outlined in 8 3 2
           Orthophosphate
 8 3   Orthophosphate
      8 3 1 The pH of the sample must be adjusted to 70 2 using a pH meter
      832 Add 8 0 ml  of combined reagent (7 5) to sample and mix  thoroughly  After a
           minimum of ten minutes, but no longer than thirty minutes, measure the color
           absorbance of each sample at 650 or 880 nm with a spectrophotometer, using the
           reagent blank as the reference solution
           NOTE 1: If the same volume of sodium hydroxide solution is not used to adjust the
           pH of the standards and samples, a volume correction has to be employed
 Calculation
 9 1   Prepare a standard curve by  plotting the absorbance values of standards versus the
      corresponding phosphorus concentrations
      9 1 1 Process standards and blank exactly as the samples Run at least a blank and two
            standards with each series of samples  If the standards do not agree within 2% of
            the true value, prepare a new calibration curve
 9 2  Obtain  concentration value of sample directly from prepared standard curve Report
      results as P, mg/1  SEE NOTE 1.
                                     365 2-5

-------
 10   Precision and Accuracy
      10 1  Thirty-three analysts in nineteen laboratories analyzed natural water samples containing
            exact increments of organic phosphate, with the following results
       Increment as
     Total Phosphorus
        mg  P/liter

          0110
          0132
          0772
          0882
                               Precision as
                            Standard Deviation
                                mg P/liter

                                   0033
                                   0051
                                   0130
                                   0128
          Accuracy as
Bias,
+ 309
+ 1199
+296
-092
Bias
mg P/hter
+0003
+0016
+0023
-0008
(FWPCA Method Study 2, Nutrient Analyses)

      10 2  Twenty-six analysts m sixteen laboratories analyzed natural water samples containing
           exact increments of orthophosphate, with the following results
       Increment as
     Orthophosphate
        mg P/liter

         0029
         0038
         0335
         0383
                               Precision as
                            Standard Deviation
                                mg P/liter

                                  0010
                                  0008
                                  0018
                                  0023
 Bias,
-495
-600
-275
-176
          Accuracy as
  "Has;
mg P/liter

   -0001
   -0002
   -0009
   -0007
(FWPCA Method Study 2, Nutrient Analyses)
                                       Bibliography
1
      Murphy, J, and Riley, J , "A modified Single Solution for the Determination of Phosphate in
      Natural Waters", Anal Chim Acta, 27, 31 (1962)
2.    Gales, M , Jr, Julian, E, and Kroner, R , "Method for Quantitative Determination of Total
      Phosphorus in Water", Jour AWWA,58,No 10,1363(1966)
3.    Annual Book of ASTM Standards, Part 31, "Water", Standard D515-72, Method A, p 389
      (1976)
4     Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 476 and 481
      (1975)
                                         365 2-6

-------
                         PHOSPHORUS, ALL  FORMS

           Method 365.3 (Colorimetric, Ascorbic Acid, Two Reagent)

                                                      STORET NO. See Section 4

1    Scope and Application
     1 1   These methods cover the determination of specified forms of phosphorus in drinking,
          surface and saline waters, domestic and industrial wastes
     1 2   The methods are based on reactions that are specific for the orthophosphate ion  Thus,
          depending on the prescribed pretreatment of the sample, the various forms may be
          determined
          121 Except for in-depth and detailed studies, the most commonly measured forms are
               phosphorus  and  dissolved  phosphorus,  and  orthophosphate  and dissolved
               orthophosphate Hydrolyzable phosphorus is normally found only in sewage-type
               samples and insoluble forms of phosphorus are determined by calculation
     1 3   The methods are usable in the 0 01 to 1 2 mg P/1 range
2    Summary of Method
     2 1   Ammonium molybdate and antimony potassium tartrate react in an acid medium with
          dilute solutions of phosphorus to form an antimony-phospho-molybdate complex This
          complex is reduced to an intensely blue-colored complex by ascorbic acid The color is
          proportional to the phosphorus, concentration
     2 2  Only orthophosphate forms a blue color in this test Polyphosphates (and some organic
          phosphorus compounds) may be converted to the orthophosphate form by sulfunc-acid-
          hydrolysis  Organic phosphorus compounds may be converted to the orthophosphate
          form by persulfate digestion
3    Sample Handling and Preservation
     3 1  If benthic deposits are present in the area being sampled, great care should be taken not
          to include these deposits
     3 2  Sample containers may be of plastic material, such as cubitamers, or of Pyrex glass
     33  If the analysis cannot be performed the day of collection, the sample should be preserved
          by the addition of 2 ml cone H2SO4 per liter and refrigeration at 4C
4    Definitions and Storet Numbers
     4 1  Total Phosphorus (P)  all of the phosphorus present in the sample, regardless of form,
          as measured by the persulfate digestion procedure (00665)
          411 Total Orthophosphate (P, ortho)  inorganic phosphorus [(PO4)~3] in the sample
                as measured by the direct colonmetnc analysis procedure (70507)
          412 Total  Hydrolyzable Phosphorus  (P,  hydro) - phosphorus  in  the  sample as
                measured by the sulfunc acid hydrolysis procedure, and minus pre-determmed
                orthophosphates  This  hydrolyzable  phosphorus  includes polyphosphorus
                [(PzOy)"4, (P3O10)"5, etc ] plus some organic phosphorus (00669)

 Approved for  NPDES
 Issued 1978

                                         365 3-1

-------
           413 Total  Organic Phosphorus  (P, org)  phosphorus (inorganic plus  oxidizable
                 organic) in the sample measured by the persulfate digestion procedure,  and minus
                 hydrolyzable phosphorus and orthophosphate (00670)
      4 2  Dissolved Phosphorus (P-D)  all of the phosphorus present m the filtrate of a sample
           filtered through a phosphorus-free filter of 0 45 micron pore size and measured by the
           persulfate digestion procedure (00666)
           4 2 1  Dissolved Orthophosphate (P-D, ortho)  as measured by the direct colonmetnc
                 analysis procedure (00671)
           422  Dissolved Hydrolyzable Phosphorus (P-D, hydro)  as measured by the sulfunc
                 acid hydrolysis procedure and minus pre-determmed dissolved orthophosphates
                 (00672)
           423  Dissolved Organic Phosphorus (P-D, org)  as measured by the  persulfate
                 digestion procedure,  and  minus  dissolved  hydrolyzable  phosphorus  and
                 orthophosphate (00673)
      4 3   The following forms, when sufficient amounts of phosphorus are present in the sample to
           warrant such consideration, may be calculated
           4.31  Insoluble Phosphorus (P-I)=(P)-(P-D) (00667)
                 4311     Insoluble orthophosphate (P-I,  ortho) = (P, ortho)  - (P-D,  ortho)
                           (00674)
                4312     Insoluble Hydrolyzable Phosphorus (P-I, hydro)=(P, hydro) - (P-D,
                           hydro) (00675)
                4313     Insoluble Organic  Phosphorus  (P-I,  org) = (P,  org)  - (P-D, org)
                           (00676)
      44   All phosphorus forms shall be reported as P, mg/1, to the third place
5.    Interferences
      5.1   Arsenate is determined similanly to phosphorus and should be considered when present
           This interference may be eliminated by reducing the arsenic acid to arsemous acid with
           sodium bisulfite (7 4)
      5 2   When high concentrations  of iron are present low  recovery  of phosphorus  will be
           obtained because it will use some of the reducing agent The bisulfite treatment will also
           eliminate this interference
6.    Apparatus
      6.1   Photometer-A spectrophotometer or filter photometer suitable for measurements at 660
           or 880 nm with a light path of 1 cm or longer
      6 2   Acid-washed glassware All glassware used should be washed  with hot 1 1  HC1  and
           nnsed with distilled water The acid-washed glassware should  be filled with distilled
           water and treated with all the reagents to remove the last traces of phosphorus that might
           be absorbed on the glassware Preferably,  this glassware should be used only  for the
           determination of phosphorus and after use it should be rinsed with distilled water  and
           kept covered until needed again If this is done, the treatment with 1 1 HC1 and reagents
           is only required occasionally Commercial detergents should never be used
     6.3   Water bath, 95C
                                         365 3-2

-------
Reagents
7 1   Ammonium  molybdate-antimony  potassium  tartrate  solution   Dissolve  8  g of
     ammonium molybdate and 0 2 g antimony potassium tartrate in 800 ml of distilled water
     and dilute to 1 liter
7 2   Ascorbic acid solution  Dissolve 60 g of ascorbic acid in 800 ml of distilled water and
     dilute to 1 liter Add 2 ml of acetone This solution is stable for two weeks
7 3   Sulfunc acid, 11 N Slowly add 310 ml of cone  H2SO4 to approximately 600 ml distilled
     water Cool and dilute to 1000 ml
7 4   Sodium bisulfite (NaHSO3) solution  Dissolve 5 2 g of NaHSO3 in 100 ml of 1 0 N
     H2S04
7 5   Ammonium persulfate
7 6   Stock phosphorus solution Dissolve 0 4393 g of predned (105C for one hour) KH2PO4
     in distilled water and dilute to 1000 ml 1 0 ml = 0 1 mg P
7 7   Standard phosphorus solution  Dilute 100 ml of stock phosphorus solution to 1000 ml
     with distilled water 10ml = 001mgP Prepare an appropriate series of standards by
     diluting suitable volumes of standard or stock solutions to 100 ml with distilled water
Procedure
8 1   Total Phosphorus
     8 1 1  Transfer 50 ml of sample or an aliquot diluted to 50 ml into a 125 ml Erlenmeyer
           flask and add 1 ml of 11 N sulfunc acid (7 3)
     812  Add 0 4 g ammonium persulfate (7 5),  mix and boil gently for approximately
           30-40 minutes or until a final volume of about 10 ml is reached Alternatively heat
           for 30 minutes in an autoclave at 121C (15-20 psi) Cool, dilute to approximately
           40 ml and filter
     813  For samples containing arsenic or high levels of iron, add 5 ml of sodium bisulfite
           (7 4), mix and place in a 95C  water bath for 30 minutes (20 minutes after the
           temperature of the sample reaches 95C) Cool and dilute to 50 ml
     814  Determine phosphorus as outlined in (8 3) orthophosphate
8 2  Hydrolyzable Phosphorus
     821  Add 1 ml of H2SO4 solution (8 3) to a 50 ml sample in a 125 ml Erlenmeyer flask
     822  Boil gently on a pre-heated hot  plate for 30-40 minutes or until a final volume of
           about 10 ml is reached Do not  allow sample to go to dryness Alternatively, heat
           for 30 minutes in an autoclave at 121C (15-20 psi)  Cool, dilute to approximately
           40 ml and filter
     823  Treat the samples as in 8 1 3
     824 Determine phosphorus as outlined in (8 3) orthophosphate
8 3  Orthophosphate
     831  To 50 ml of sample and/or standards, add 1 ml of 11 N sulfunc acid  (7 3) and 4 ml
           of ammonium molybdate-antimony potassium tartrate (7 1) and mix
           NOTE: If sample has been digested for total or hydrolyzable phosphorus do not
           add acid
      832 Add 2 ml of ascorbic acid solution (7 2) and mix
                                     365 3-3

-------
           833 After 5 minutes, measure the absorbance at 650 run with a spectrophotometer and
                determine the phosphorus concentration from the standard curve The color is
                stable for at least one hour For concentrations in the range of 0 01 to 0 3 mg P/l, a
                5 cm cell should be used A one cm cell should be used for concentrations in the
                range of 0 3 to 1 2 mg P/l
9    Calculation
     9 1   Prepare a standard curve by  plotting the absorbance values  of standards versus  the
           corresponding phosphorus concentrations on linear graph paper
     9 2   Obtain concentration value of sample directly from prepared standard curve Report
           results as P, mg/1
10   Precision and Accuracy
     10 1  Precision data is not available at this time
     102  In  a  single  laboratory (EMSL) using industrial  waste and sewage  samples  at
           concentrations of 7 6 and 0 55 mg P/l, recoveries were 99 and 100%, respectively
                                          365 3-4

-------
                             PHOSPHORUS, TOTAL

        Method 365.4 (Colorimetric, Automated,  Block Digester AA II)

                                                                STORET NO. 00665

1    Scope and Application
     1 1  This method covers the determination of total phosphorus in drinking water, surface
          water and domestic and industrial wastes The applicable range of this method is 0 01 to
          20mgP/l
2    Summary of Method
     2 1  The sample is heated in the presence of sulfunc acid, K2SO4 and HgSO4 for two and one
          half hours The residue is cooled, diluted to 25 ml and placed on the AutoAnalyzer for
          phosphorus determination
3    Sample Handling and Preservation
     3 1  Sample containers may be of plastic material, such as a cubitainer, or of Pyrex glass
     32  If the analysis cannot be performed the day of collection, the sample should be preserved
          by the addition of 2 ml of cone H2SO4 per liter and refrigeration at 4C
4    Apparatus
     4 1  Block Digestor BD-40
     42  Techmcon Method No 327-74W for Phosphorus
5    Reagents
     5 1  Mercuric sulfate Dissolve  8 g red mercuric oxide (HgO) in 50 ml of 1 4 sulfunc acid
          (10 cone H2SO4 40 ml distilled water) and dilute to 100 ml with distilled water
     5 2  Digestion  solution  (Sulfunc acid-mercunc sulfate-potassium sulfate solution) Dissolve
           133 g of K2SO4 in 600 ml of distilled water and 200 ml of cone H2SO4 Add 25 ml of
          mercunc svlfate solution (5 1) and dilute to 1 liter
     5 3  Sulfunc acid solution (0 72 N) Add 20 ml of cone sulfunc acid to 800 of distilled water,
          mix and dilute to 1 liter
     5 4  Molybdate/antimony  solution  Dissolve 8 g of ammonium molybdate and 0 2  g of
          antimony potassium tartrate m about 800 ml of distilled water and dilute to 1 liter
     5 5  Ascorbic acid solution Dissolve 60 g of ascorbic acid in about 600 ml of distilled water
          Add 2 ml of acetone and dilute to 1 liter
     5 6  Diluent water  Dissolve 40 g of Nad in about 600 ml of distilled water and dilute to  1
          liter
     5 7  Sulfunc acid solution,  4%  Add 40 ml of cone sulfunc acid to 800 ml of ammonia-free
          distilled water, cool and dilute to 1 liter
6    Procedure
     Digestion
     61  To 20 or 25 ml of sample, add 5 ml of digestion solution and mix (Use a vortex mixer)
     6 2  Add 4-8 Teflon boiling chips Too many boiling chips will cause the sample to boil over

Pending approval for NPDES and Section 304(h), CWA
Issued 1974

                                        3654-1

-------
      6 3   With Block Digester in manual mode set low and high temperature at 160C and preheat
           unit to 160C Place tubes m digester and switch to automatic mode  Set low temperature
           timer for 1 hour Reset high temperature to 380C and set timer for 21/2 hours
      6 4   Cool sample and dilute to 25 ml with distilled water If TKN is determined the sample
           should be diluted with ammonia-free water
      Colonmetnc Analysis
           641 Check the level of all reagent containers to ensure an adequate supply
           642 Excluding the molybdate/antimony line, place all reagent lines in their respective
                containers, connect the sample probe to the Sampler IV and start the proportioning
                pump
           643 Flush the Sampler IV wash receptacle with about 25 ml of 4% sulfunc acid (5 7)
           644 When  reagents  have been  pumping for at least five  minutes,  place  the
                molybdate/antimony line in its container and allow the system to equilibrate
           645 After a stable baseline has been obtained, start the sampler
7     Calculations
      7 1   Prepare a  standard curve by plotting peak heights of processed standards against
           concentration values Compute concentrations by comparing sample peak heights with
           the standard curve
8.    Precision and Accuracy
      81   In a single laboratory (EMSL) using sewage sample containing total P at levels of 0 23,
           1  33, and 2 0, the precision was 001, 004, and 0 06, respectively
      82   In a single  laboratory (EMSL) using sewage samples of concentration 1 84 and 1 89, the
           recoveries were 95 and 98%, respectively

                                      Bibliography

1     McDamel, W H  , Hemphill, R N and Donaldson, W T, "Automatic Determination of Total
      Kjeldahl Nitrogen in Estuarme Water", Techmcon Symposia, pp 362-367, Vol 1,1967
2     Gales, M.E and Booth, R L , "Evaluation of Organic Nitrogen Methods", EPA Office of
      Research and Monitoring, June, 1972
3     Gales, ME  and Booth,  RL, "Simultaneous  and Automated  Determination of  Total
      Phosphorus and Total Kjeldahl Nitrogen", Methods Development and Quality  Assurance
      Research Laboratory, May, 1974
4.     Techmcon "Total Kjeldahl Nitrogen and Total Phosphorus BD-40 Digestion Procedure for
      Water", August,  1974
5     Gales, M E, and Booth, R L, "Evaluation of the Techmcon  Block Digestor System for the
      Measurement  of Total Kjeldahl Nitrogen and Total Phosphorus",  EPA-600 /4-78-015,
      Environmental Monitoring and Support Laboratory, Cincinnati, Ohio
                                         365 4-2

-------
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365 4-3

-------
                               SILICA, DISSOLVED

                            Method 370.1 (Colorimetric)

                                                     STORET NO. Dissolved 00955

 1     Scope and Application
      1 1   This method is applicable to drinking, surface and saline waters, domestic and industrial
           wastes
      1 2   The working range of the method is approximately 2 to 25 mg silica/1 The upper range
           can be extended by taking suitable ahquots, the lower range can be extended by the
           addition of ammo-naphthol-sulfonic acid solution, as described in (6 8)
 2     Summary of Method
      21   A well-mixed sample is filtered through a 0 45 u membrane filter The filtrate, upon the
           addition of  molybdate ion m acidic solution, forms a greenish-yellow color complex
           proportional to the dissolved silica in the sample The color complex is then measured
           spectrophotometncally
      22   In the low concentration modification the yellow (410 nm) molybdosihcic acid color is
           reduced by  l-amino-2-naphthol-4-sulfomc acid to a more intense heteropoly blue (815
           nm or 650 nm)
 3     Interferences
      3 1   Excessive color and/or turbidity interfere  Correct by running blanks prepared without
           addition of the ammonium molybdate solution See (6 7)
      3 2   Tannin interference may be eliminated and phosphate interferences may be decreased
           with oxalic acid
      3 3   Large amounts of iron and sulfide interfere
      3 4   Contact with glass should be minimized, silica free reagents should be used as much as
           possible A blank should be run
4     Apparatus
      4 1   Platinum dishes, 100 ml
      4 2   Colorimetric equipment-one of the following
           421  Spectrophotometer for use at 410 nm, 650 nm and/or 815 nm with a 1 cm or longer
                cell
           422  Filter photometer with a violet filter having maximum transmittance as near 410
                nm as possible and a 1 cm or longer cell
           423  Nessler tubes, matched, 50 ml, tall form
5     Reagents
      5 1   Use chemicals low m silica and store in plastic containers
      5 2   Sodium bicarbonate, NaHCO3, powder
      5 3   Sulfunc acid, H2SO4, 1 N_

Approved for NPDES
Issued 1971
Editorial revision 1978

                                         370 1-1

-------
5 4  Hydrochloric acid, HC1,1 + 1
5 5  Ammonium molybdate reagent Place 10 g (NH4)6Mo7O244H2O m distilled water in a
     100 ml volumetric Dissolve by stirring and gently warming Dilute to the mark Filter if
     necessary Adjust to pH 7 to 8 with silica free NH4OH or NaOH Store in plastic bottle
5 6  Oxalic acid  solution  Dissolve  10  g H2C2O42H2O m distilled water in a 100 ml
     volumetric flask, dilute to the mark Store m plastic
5 7  Stock silica solution Dissolve 4 73 g sodium metasilicate nonahydrate, Na2SiO39H2O,
     in recently boiled and cooled distilled water Dilute to approximately 900 ml Analyze
     100 0 ml portions by gravimetry (ref 1, p  484) Adjust concentration to  1 000 mg/1
     SiO2 Store m tightly stoppered plastic bottle
5.8  Standard silica solution Dilute 10 0 ml stock solution to 1 liter with recently boiled and
     cooled distilled water This is 10 mg/1 SiO2 (1 00 ml =  10 0 ug SiO2)  Store m a tightly
     stoppered plastic bottle
5.9  Permanent color solutions
     591 Potassium chromate solution  Dissolve 630 mg K2CrO4 in distilled water m a 1
          liter volumetric flask and dilute to the mark
    '592 Borax solution  Dissolve  10 g sodium borate decahydrate, (Na2B4O710H2O) m
          distilled water in a 1 liter volumetric flask and dilute to the mark
5.10 Reducing agent Dissolve 500 mg of l-amino-2-naphthol-4-sulfonic acid and 1 g Na2SO3
     m 50 ml distilled water with gentle warming if necessary Dissolve 30 g NaHSO3 in 150
     ml distilled water Mix these two solutions Filter into a plastic bottle Refrigerate and
     avoid  exposure to light Discard when  it darkens  If there is incomplete solubility or
     immediate darkening of the ammonaphthosulfonic acid solution do not use
Procedure
6 1  Filter sample through a 0 45 u membrane filter
6 2  Digestion  If molybdate unreactive  silica is present and its  inclusion m the analysis is
     desired, include this step, otherwise proceed to 6 3
     621 Place 50 ml, or a smaller portion diluted to 50 ml, of filtered (61) sample m a 100
          ml platinum dish
     622 Add 200 mg silica-free NaHCO3 (5 2) and digest on a steam bath for 1 hour Cool
     623 Add slowly and with stirring 2 4 ml H2SO4 (5 3)
     624 Immediately  transfer to a 50  ml Nessler tube, dilute to the mark with distilled
          water and proceed to 6 3 without delay
6 3  Color development
     631 Place 50 ml sample in a Nessler tube
     632 Add rapidly 1 0 ml of 1 +1 HC1 (5 4) and 2 0 ml ammonium molybdate reagent
          (55)
     633 Mix by inverting at least 6 times
     634 Let stand 5 to 10 minutes
     635 Add 1 5 ml oxalic acid solution (5 6) and mix thoroughly
     636 Read color (spectrophotometncally or visually)  after 2 minutes  but before 15
          minutes from the addition of oxalic acid
                                     370 1-2

-------
6 4   Preparation of Standards
      6 4 1 If digestion (6 2) was used add 200 mg NaHCO3 (5 2) and 2 4 ml H2SO4 (5 3) to
           standards to compensate for silica introduced by these reagents and for effect of the
           salt on the color intensity
6 5   Photometric measurement
      651 Prepare a calibration curve using approximately six standards to span the range
           shown below with the selected light path

                         Selection of Light Path  Length for Various
                                    Silica Concentrations
66
                 Light Path
                    cm

                    1
                    2
                    5
                   10
                                                      Silica in 54 5  ml
                                                      final volume (ug)

                                                      200-1300
                                                       100-700
                                                        40-250
                                                        20-130
652 Carry out the steps in 6 3 using distilled water as the reference Read a blank
653 Plot photometric reading versus ug of silica in the final solution of 54 5 nil Run a
     reagent blank and at least one standard with each group of samples
Visual Comparison
6 6 1 Prepare a set of permanent artificial color standards according to the table  Use
     well stoppered, properly labelled 50 ml Nessler tubes
                        Potassium
                        chromate
                         solution
                        (5 9 1) ml

                           00
                           10
                           20
                           40
                           50
                           75
                          100
                                              Borax
                                             solution
                                            (5 9 2) ml

                                              25
                                              25
                                              25
                                              25
                                              25
                                              25
                                              25
Distilled
 water
  ml

  30
  29
  28
  26
  25
  22
  20
     662 Verify permanent standards by comparison to color developed by standard silica
          solutions
     663 These permanent artificial color standards  are  only for color  comparison
          procedure, not for photometric procedure
     Correction for color or turbidity
     6 7 1 A special blank is run using a portion of the sample and carrying out the procedure
          in 6  1, 6 2 if used, and 6 3 except for the addition of ammonium molybdate ^6 3 2)
                                    370 1-3

-------
     672 Zero the photometer with this blank before reading the samples
6.8  Procedure for low concentration ( < 1000 ug/1)
     681 Perform steps 6 1 and 6 2 if needed
     682 Place 50 ml sample in a Nessler tube
     6 8 3 In rapid succession add 1 0 ml of 1 +1 HC1 (5 4)
     684 Add 2 0 ml ammonium molybdate reagent (5 5)
     685 Mix by inverting at least six times
     6.8 6 Let stand 5 to 10 minutes
     687 Add 1 5 ml oxalic acid solution (5  6)
     6 8.8 Mix thoroughly
     6 8.9 At least 2, but not more than 15 minutes after oxalic acid addition, add 2 0 ml
           reducing agent (5 10)
     6 8 10 Mix thoroughly
     6811 Wait 5 minutes, read photometrically or visually
     6 8 12 If digestion (6 2)  was used see (6 4)
     6813 Photometric measurement
           6 8 13  1    Prepare a calibration  curve  using approximately 6 standards and a
                     reagent blank to span the range shown below with the selected light
                     path
                                Selection of Light Path Length for
                                  Various Silica  Concentrations

                   Light Path                 Silica  in 56 5 ml Final volume,  ug
                   	!S	        650  nm                       815 nm

                        1              40-300                       20-100
                       2              20-150                       10-50
                       5               7-50                         4-20
                       10              4-30                         2-10

           68132    Read versus distilled water
           68133    Plot photometric reading at 650 nm or at 815 nm versus ug of silica in
                     56 5 ml.
           68134    For turbidity correction use 6 1, 6 2 if used and 6 8 2-6 811 omitting
                     684and689
           6 8 13 5    Run a reagent blank and at  least one standard (to check calibration
                     curve drift) with each group of samples
     6 8 14    Visual comparison
           6 8 14 1    Prepare not less than  12 standards covering the range of 0 to 120 ug
                     SiO2 by placing the calculated volumes of standard silica (5 8) in 50 ml
                     Nessler tubes, diluting to the  mark  and develop  the  color as in
                     682-68 11
                                    370 1-4

-------
7    Calculations
     7 1  Read ug SiO2 from calibration curve or by visual comparison
     7 2  mg/1 Si02 =
                         ug/SiO2
                        ml sample

      7 3   Report whether NaHCO3 digestion (6 2) was used
 8    Precision and Accuracy
      81   A synthetic unknown sample containing 5 0 mg/1 SiO2, 10 mg/1 chloride, 0 200 mg/1
           ammonia N, 1 0 mg/1 nitrate N, 1 5 mg/1  organic N, and  10 0 mg/1  phosphate in
           distilled water was analyzed in 19 laboratories by the molybdosihcate method, with a
           relative standard deviation of 143% and a relative error of 7 8%
      8 2   Another synthetic  unknown  sample containing 15 0 mg/1 SiO2, 200 mg/1 chloride,
           0 800  mg/1 ammonia N,  1 0 mg/1 nitrate N, 0 800 mg/1 organic N, and 5  0 mg/1
           phosphate in distilled water  was analyzed in 19 laboratories by the molybdosihcate
           method, with a relative standard deviation of 8 4% and a relative error of 4 2%
      83   A third synthetic unknown sample containing 30 0 mg/1 SiO2, 400 mg/1 chloride, 1 50
           mg/1  ammonia  N, 1 0 mg/1  nitrate  N,  0 200 mg/1 organic N, and 0 500 mg/1
           phosphate in distilled water  was analyzed in 20 laboratories by the molybdosihcate
           method, with a relative standard deviation of 77% and a relative error of 9 8% All
           results were obtained after sample digestion with NaHCO3
      8 4   Photometric evaluations  by  the ammo-naphthol-sulfonic acid procedure have an
           estimated precision of 010 mg/1 in the range from 0 to 2 mg/1 (ASTM)
      8 5   Photometric evaluations of the sihco-molybdate color in the range from 2 to 50 mg/1
           have an estimated  precision of approximately 4% of the quantity of silica measured
           (ASTM)

                                      Bibliography

 1     Annual Book of ASTM Standards, Part 31, "Water", Standard D859-68, p 401 (1976)
 2    Standard Methods for the Examination  of Water and  Wastewater,  14th Edition, p 487,
      Method 426B,( 1975)
                                         370 1-5

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                                       SULFATE

               Method 375.1 (Colorimetric, Automated, Chloranilate)

                                                          STORET NO. Total 00945

 1     Scope and Application
      1 1   This automated method is applicable to drinking and surface waters, domestic and
           industrial wastes, in the range of 10 to 400 mg SO4/1 Approximately 15 samples per
           hour can be analyzed
 2     Summary of Method
      2 1   When solid barium chloramlate is added to a solution containing sulfate, barium sulfate
           is precipitated, releasing the highly colored acid chloramlate ion The color intensity in
           the resulting chloramhc acid is proportional to the amount of sulfate present
 3     Sample Handling and Preservation
      3 1   Refrigeration at 4C
 4     Interferences
      4 1   Cations, such as calcium, aluminum, and iron, interfere by precipitating the chloramlate
           These ions are removed automatically by passage through an ion exchange column
 5     Apparatus
      5 1   Techmcon AutoAnalyzer consisting of
           5  1 1 Sampler I
           512 Continuous filter
           5  1 3 Manifold
           514 Proportioning pump
           515 Colorimeter equipped with 15 mm tubular flow cell and 520 nm filters
           516 Recorder
           5  17 Heating bath, 45C
      5 2   Magnetic stirrer
6     Reagents
      6 1   Barium chloramlate  Add 9 g of barium chloramlate (BaC6Cl2O4) to  333 ml of ethyl
           alcohol and dilute to 1 liter with distilled water
      6 2   Acetate buffer, pH 4 63 Dissolve 13 6 g of sodium acetate in distilled water Add 6 4 ml
           of acetic acid and dilute to 1 liter with distilled water Make fresh weekly
      6 3   NaOH-EDTA solution Dissolve 65 g of NaOH and 6 g of EDTA in distilled water and
           dilute to 1 liter
           NOTE 1: This solution is also used to clean out manifold system at end of sampling run
      6 4   Ion exchange resin  Dowex-50 W-X8, ionic form-H+
           NOTE 2: Column is prepared by sucking a slurry of the resin into 12 inches of 3/16-inch
           OD sleeving This may be conveniently done by using a pipette and a loose-fitting glass
           wool plug in the sleeve The column, upon exhaustion, turns redv


Issued 1971

                                         375 1-1

-------
      6 5   Stock solution Dissolve 1 4790 g of oven-dried (105C) Na2SO4 in distilled water and
           dilute to 1 liter ma volumetric flask 1 0 ml  =10mg
           651 Prepare a series of standards by diluting suitable volumes of stock solution to 100 0
                ml with distilled water The following dilutions are suggested

                  ml of Stock Solution                               Cone, mg/1
                        10                                            10
                        20                                            20
                        40                                            40
                        60                                            60
                        80                                            80
                       10 0                                           100
                       15 0                                           150
                       200                                           200
                       300                                           300
                       400                                           400

7.   Procedure
     7.1   Set up manifold as shown in Figure 1  (Note that any precipitated BaSO4 and the unused
           barium chloramlate are removed by filtration  If any BaSO4 should come through the
           filter, it is complexed by the NaOH-EDTA reagent)
     7 2   Allow both colorimeter and recorder to warm up for 30 minutes Run a baseline with all
           reagents, feeding distilled  water through the  sample line  Adjust dark current and
           operative opening on colorimeter to obtain suitable baseline
     7 3   Place distilled water wash tubes in alternate openings in sampler and set sample timing at
           2 0 minutes
     7 4   Place working standards in sampler in order  of decreasing concentration Complete
           filling of sampler tray with unknown samples
     7 5   Switch sample line from distilled water to sampler and begin analysis
8.   Calculation
     8 1   Prepare  standard curve by plotting peak heights of processed standards against known
           concentrations Compute concentration of samples by comparing sample peak heights
           with standard curve
9.   Precision and Accuracy
     9.1   In a single laboratory (EMSL), using surface water samples at concentrations of 39, 111,
           188 and 294 mg SO4/1, the standard deviations were  06,  10,  22 and  08,
           respectively
     92   In a single laboratory (EMSL), using surface water samples at concentrations of 82 and
           295 mg SO4/1, recoveries were 99% and 102%, respectively

                                       Bibliography

1    Barney, J E, and Bertolocmi, R J , Anal  Chem , 29,283 (1957)
2    Gales, M E, Jr,  Kaylor, W  H  and Longbottom, J  E, "Determination of Sulphate  by
     Automatic Colonmetnc Analysis", Analyst, 93,97 (1968)
                                         375 1-2

-------
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                   375 1-3

-------
                                    SULFATE

    Method  375.2  (Colorimetric, Automated,  Methylthymol  Blue, AA II)

                                                              STORET NO. 00945

    Scope and Application
    1 1  This automated method is applicable to drinking and surface waters, domestic and
         industrial wastes
    1 2  Samples in the range of 3 to 300 mg SO4/1 can be analyzed The sensitivity of the method
         can be increased by a minor modification to analyze samples in the range of 0 5 to 30 mg
         SO4/1 Approximately 30 samples per hour can be analyzed
    Summary of Method
    2 1  The sample is first passed through a sodium form cation-exchange column to remove
         multivalent metal ions  The sample containing sulfate is then reacted with an alcohol
         solution of barium chloride and methylthymol blue (MTB) at a pH of 2 5-3 0 to form
         barium sulfate  The combined solution is raised to a pH of 12 5-13 0 so that excess
         barium reacts with MTB The uncomplexed MTB color is gray, if it is all chelated with
         barium, the color is blue Initially, the barium and MTB are equimolar and equivalent to
          300 mg SO4/1, thus the amount of uncomplexed MTB is equal to the sulfate present
    Sample Handling and Preservation
    3 1   Refrigeration at 4C
    Interferences
    4 1   The ion exchange column eliminates interferences from multivalent cations A mid-scale
          sulfate  standard containing Ca++ should be analyzed periodically to insure that the
          column is functioning properly
    4 2   Samples with pH below 2 should be neutralized because high acid concentrations elute
          cations from the ion exchange resin
    4 3   Turbid samples should be filtered or centnfuged
    Apparatus
    5  1   Techmcon Auto Analyzer consisting of
          511 Sampler
          512 Manifold-high or low level (Figure I)
          513 Proportioning pump
          514 Colorimeter equipped with 15 mm flow cell and 460 nm interference filters
          515 Recorder
          516 Digital Printer for AAII (optional)
     Reagents
     6 1   Barium chloride Dissolve 1 526 g of barium chloride dihydrate (BaCl22H2O) in 500 ml
          of distilled water and dilute to 1 liter
Pending approval for NPDES
Issued 1978

                                        375 2-1

-------
 62  Methylthymol  blue  Dissolve  01182  g of  methylthymol  blue (3'3"-bis-N,N-bis
      carboxymethyl)-amino methylthymolsulfone-phthalem pentasodmm salt) in 25 ml of
      barium chloride solution (6 1) Add 4 ml of 1 0 N hydrochloric acid which changes the
      color to bright orange Add 71 ml of water and dilute to 500 ml with ethanol  The pH of
      this solution is 2 6 This reagent should be prepared the day before and stored in a brown
      plastic bottle in the refrigerator
 6 3  Buffer, pH 10 5 05 Dissolve 6 75 g of ammonium chloride  in 500 ml of distilled
      water  Add  57 ml of concentrated ammonium hydroxide and dilute to one liter with
      distilled water
 6 4  Buffered EDTA Dissolve 40 g of tetrasodium EDTA in pH 10 5 buffer (6 3), and dilute
      to one liter with buffer
 6 5   Sodium hydroxide solution, (50%) Dissolve 500 g NaOH in 600 ml of distilled water,
      cool, and dilute to 1 liter
 6 6   Sodium hydroxide, 0 18N Dilute 14 4 ml of sodium hydroxide solution (6 5) to 1 liter
 6 7   Ion exchange  resin   Bio-Rex 70,  20-50 mesh, sodium form, Bio-Rad Laboratories,
      Richmond, California Free from  fines  by stirring with several portions of deiomzed
      water and decant the supernate before settling is complete
 6 8   Dilution Water Add 0 75 ml of sulfate stock solution (6 9) and 3 drops of Bnj-35 to 2
      liters of distilled water
 6 9   Sulfate stock solution, 1 ml = 1 mg SO4 Dissolve 1 479 g of dried (105C) Na2SO4 in
      distilled water and dilute to 1 liter
 6 10  Dilute sulfate solution, 1 ml = 0 1  mg SO4  Dilute 100 ml of sulfate stock solution (6 9)
      to 1 liter
 6 11  High level working standards, 10-300 mg/1 Prepare high level working standards by
      diluting the following volumes of stock standard (6 9) to 100 ml

                  ml stock                                     mg/1 SO4

                    1                                             10
                    5                                             50
                   10                                           100
                   15                                           150
                   25                                           250
                   30                                           300

6 12 Low level working standards, 1-30 mg/1  Prepare low  level working standards by
     diluting the following volumes of dilute sulfate solution (6 10) to 100 ml

                  ml stock                                     mg/1 SO4

                    1                                           10
                    5                                           50
                   10                                           100
                   15                                           150
                   25                                          250
                   30                                          300
                                    375 2-2

-------
7    Procedure
     7 1  Set up the manifold for high (0-300 mg SO4/1) or low (0-30 mg SO4/1) level samples as
          described in Figure I
     7 2  The ion exchange column is prepared by pulling a slurry of the resin into a piece of glass
          tubing 7 5 inches long, 2 0 mm ID and 3 6 mm OD This is conveniently done by using a
          pipet and a loose fitting glass wool plug in the tubing  Care should be taken to avoid
          allowing air bubbles  to enter the column  If air bubbles become trapped, the column
          should be prepared over  again The column can exchange the equivalent of 35 mg of
          calcium  For the high level manifold  this  corresponds to about  900 samples with 200
          mg/1 Ca   The column should be prepared as often as necessary to assure that no more
          than 50% of its capacity is used up
     7 3  Allow the colorimeter, recorder and printer to warm up for 30 minutes Pump all
          reagents until a stable baseline is achieved
     7 4  Analyze all working standards in duplicate at the beginning of a run  to develop a
          standard curve The A and B control standards are analyzed every hour to assure that the
          system remains properly calibrated  Since the chemistry is  non-linear the 180 mg/1
          standard is set at 50% on the recorder using the standard calibration control on the
          colorimeter
     75  At the end of each day, the system should  be washed with the buffered EDTA solution
          (6 4)  This is done by placing the methylthymol blue line and the  sodium hydroxide line
          in water for a few minutes and then in the buffered EDTA solution for 10 minutes Wash
          the system with water for 15 minutes before shutting down
8    Calculation
     8 1  Prepare a standard curve by plotting peak heights of processed standards against known
          concentrations Compute concentration of samples by comparing sample peak heights
          with the standard curve
9    Precision and Accuracy
     91  In  a  single laboratory the estimated standard deviation, calculated from duplicate
          analyses of 26 surface and wastewaters at a mean concentration of 110 mg/1 was +16
          mg/1
     9 2  The mean recovery from 24 surface and wastewaters was  102%

                                      Bibliography

1    Lazrus, A L , Hill, K C  and Lodge, J P , "Automation in Analytical Chemistry", Techmcon
     Symposia, 1965
2    Coloros, E,  Panesar,  M R   and Parry,  F P,  "Linearizing  the Calibration Curve m
     Determination of Sulfate by the Methylthymol Blue Method", Anal  Chem 48, 1693(1976)
                                         375 2-3

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-------
                                       SULFATE

                             Method 375.3 (Gravimetric)

                                                           STORET NO. Total 00945

1    Scope and Application
     1 1   This method is applicable to drinking, surface and saline water, domestic and industrial
           wastes
     1 2   This method is the most accurate method for sulfate concentrations above 10 mg/1
           Therefore, it should be used whenever results of the greatest accuracy are required
2    Summary of Method
     2 1   Sulfate is precipitated as barium sulfate in a hydrochloric acid medium by the addition of
           barium chloride After a period of digestion, the precipitate is filtered, washed with hot
           water until free of chloride, ignited, and weighed as BaSO4
     2 2   Preserve by refrigeration at 4C
3    Interferences
     3 1   High results may be obtained for samples that contain suspended matter, nitrate, sulfite
           and silica
     3 2   Alkali metal  sulfates frequently yield  low results  This is especially true of alkali
           hydrogen sulfates  Occlusion of alkali sulfate with barium sulfate causes the substitution
           of an element of lower atomic weight than barium in the precipitate Hydrogen sulfate of
           alkali  metal acts similarly  and decomposes when  heated   Heavy metals  such as
           chromium and iron, cause low results by interfering with complete precipitation and by
           formation of heavy metal sulfates
4    Apparatus
     4 1   Steam bath
     4 2   Drying oven, equipped with thermostatic control
     4 3   Muffle furnace with heat indicator
     4 4   Desiccator
     4 5   Analytical balance, capable of weighing to 0 1 mg
     4 6   Filter paper, acid-washed, ashless hard-finish filter paper sufficiently retentive for fine
           precipitates
5    Reagents
     5 1   Methyl red indicator solution  Dissolve 100 mg methyl red sodium salt in distilled water
           in a 100 ml volumetric flask and dilute to the mark with distilled water
     5 2   Hydrochloric acid, HC1,  1 +1
     5 3   Barium chloride solution Dissolve 100 g BaCl22H2O in 1 liter of distilled water  Filter
           through a membrane filter or hard-finish filter paper One ml of this reagent is capable of
           precipitating approximately 40 mg SO4

Approved  for NPDES
Issued 1974
Editorial revision  1978

                                          375 3-1

-------
      5 4   Silver nitrate-nitric acid reagent Dissolve 8 5 g AgNO3 and 0 5 ml cone HNO3 m 500 ml
            distilled water
 6.    Procedure
      6 1   Removal of silica If silica concentration is greater than 25 mg/1
            611  Evaporate sample nearly to dryness in a platinum dish on a steam bath
            6 1 2  Add 1  ml HC1 solution (5 2), tilt dish and rotate until acid contacts all of the
                 residue
            613  Continue evaporation to dryness
            614  Complete drying in an oven at 180C
            615  If organic matter present, char over a flame
            616  Moisten with 2 ml distilled water and 1 ml HC1 solution (5 2)
            617  Evaporate to dryness on a steam bath
            6 1 8  Add 2 ml HC1 solution (5 2)
            6.1 9  Take up soluble residue in hot distilled water and filter
            6 1 10 Wash the insoluble silica  with several small portions of hot distilled water
            6.1 11 Combine filtrate and washings
      6 2  Precipitation of barium sulfate
           621  If necessary, treat clarified sample to remove interfering agents
           622  Adjust to contain approximately 50 mg SO4 ion m a 250 ml volume
           623  Adjust acidity with HC1 solution (5 2) to pH 4 5 to 5 0, using pH meter or orange
                 color of methyl red indicator (5 1)
           624  Add an additional 1 to 2 ml HC1 solution (5 2)
           6.2 5 For lower concentrations of sulfate ion fix the total volume at 150 ml
           6 2.6 Heat to boiling and, while stirring gently, add warm BaCl2 solution (5 3) slowly,
                until precipitation appears to be complete, then add approximately 2 ml in excess
           627 If amount of precipitate is small, add a total of 5 ml BaCl2 solution (5 3)
           628 Digest the precipitate at 80 to 90C preferably overnight but for not less than 2
                hours
     6 3   Filtration and Weighing
           631 Mix a little ashless filter paper pulp with the BaSO4 and filter at room temperature
           632 Wash the precipitate with small portions of warm distilled water until the washings
               are free  of chloride as indicated by testing with  silver nitrate-nitric acid reagent
               (54)
           633 Dry the filter and precipitate
           634 Ignite at 800C for 1 hour DO NOT LET THE FILTER PAPER FLAME
           635 Cool m a desiccator and weigh
7    Calculation
                              mg/1 SO4 = mgBaSCX, x 411 5
                                              ml sample
                                         375 3-2

-------
8    Precision and Accuracy
     81  A synthetic unknown sample containing 259 mg/1 sulfate, 108 mg/1 Ca, 82 mg/1 Mg,
          3 1 mg/1 K, 19 9 mg/1 Na, 241 mg/1 chloride, 250 ug/1 nitrite N, 1 1 mg/1 nitrate N
          and 42 5 mg/1 alkalinity (contributed by NaHCO3), was analyzed in 32 laboratories by
          the gravimetric method, with a relative standard deviation of 4 7% and a relative error of
          19%

                                      Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D516-68, Method A, p 429
     (1976)
2    Standard Methods for the Examination of Water and Wastewater, 14th Edition,  p  493,
     Method 427A, (1975)
                                         375 3-3

-------
                                     SULFATE

                           Method 375.4 (Turbidimetric)

                                                        STORET NO. Total  00945

    Scope and Application
    1 1   This method is applicable to drinking and surface waters, domestic and industrial wastes
    1 2   The method is suitable for all concentration ranges of sulfate, however, m order to obtain
          reliable readings, use a sample aliquot containing not more than 40 mg SO4/1
    1 3   The minimum detectable limit is approximately 1 mg/1 sulfate
    Summary of Method
    2 1   Sulfate ion is converted to a barium sulfate suspension under controlled conditions The
          resulting  turbidity  is  determined  by  a  nephelometer,  filter  photometer  or
          spectrophotometer and compared to a curve prepared from standard sulfate solutions
    2 2   Suspended matter and color interfere Correct by running blanks from which the barium
          chloride has been omitted
    2 3   Silica in concentrations over 500 mg/1 will interfere
    Comments
    3 1   Proprietary reagents, such as Hach Sulfaver or equivalent, are acceptable
    32   Preserve by refrigeration at 4C
    Apparatus
    4 1   Magnetic starrer, variable speed so that it can be held constant just below splashing Use
          identical shape and size magnetic stirring bars
    4 2   Photometer one of the following which are given in order of preference
          421  Nephelometer
          422  Spectrophotometer for use at 420 nm with light path of 4 to 5 cm
          423  Filter photometer with a violet filter having a maximum near 420 nm and a light
                path of 4 to 5 cm.
     4 3   Stopwatch, if the magnetic stirrer is not equipped with an accurate timer
     4 4   Measuring spoon, capacity 0 2 to 0 3 ml
     Reagents
     5 1   Conditioning reagent Place 30 ml cone  HC1, 300 ml distilled water, 100 ml 95% ethanol
          or isopropanol and 75 g NaCl m solution m a container Add 50 ml glycerol and mix
     5 2   Barium chloride, BaCl2, crystals, 20 to 30 mesh
     5 3   Sodium carbonate solution (approximately 0 05N)  Dry 3 to 5  g primary standard
          Na2CO3 at 250C for 4 hours and cool in a desiccator Weigh 25 0 2 g (to the nearest
          mg), transfer to a 1 liter volumetric flask and fill to the mark with distilled water
Approved for  NPDES
Issued 1971
Editorial revision 1978

                                         375 4-1

-------
   5 4   Standard sulfate solution (1 00 ml =*= 100 ug SO4) Prepare by either 5 4 1 or 5 4 2
       5 4 1" Standard sulfate solution from H2SO4
             5411     Standard sulfunc acid, 0 IN dilute 3 0 ml cone H2SO4 to 1 liter with
                       distilled water Standardize versus 40 00 ml of 0 05 NjNa2CO3 solution
                    (   (53) with about 60 ml distilled water by titrating potentiometrically to
                      ' pH about 5 Lift electrodes and rinse into beaker Boil gently for 3-5
                       minutes under a watch glass cover Cool to room temperature Rinse
                       cover glass into beaker Continue titration to the pH inflection point
                       Calculate normality using
                                              N=   Ax  B
                                                   53 OQ x C

                       where

                       A = g Na2CO3 weighed into 1 liter
                     '  B = ml Nfa2CO3 solution
                       C = ml acid used to inflection point

            5412     Standard acid, 0 02 N^ Dilute appropriate amount of standard acid, 0 1
                       N.(5 4 1  1) to 1 liter (200 00 ml if 0 1000 N) Check by standardization
                       versus 15 ml of 0 05 N_Na2CO3 solution (5 3)
            5413     Place 10 41 ml standard sulfunc  acid, 0 02 ]S[ (5 4 1 2) in a 100 ml
                       volumetric and dilute to the mark
      542  Standard sulfate solution from Na2SO4 Dissolve 147 9 mg anhydrous Na2SO4 in
            distilled water in a 1 liter volumetric flask and dilute to the mark with distilled
            water
 Procedure
 6 1   Formation of barium sulfate turbidity
      6 1 1  Place 100 ml sample, or a suitable portion diluted to 100 ml) into a 250 Erlenmeyer
            flask
      612 Add exactly 5 0 ml conditioning reagent (5 1).
      6 1 3 Mix in the stirring apparatus
      6 1 4 While the solution is being stirred, add a measuring spoonful of BaCl2 crystals (5 2)
           and begin timing immediately
      6 1 5 Stir exactly 1 0 minutes at constant speed
6 2   Measurement of barium sulfate turbidity
      6 2 1 Immediately after the stirring period has ended, pour solution into absorbance cell
      6 2,2 Measure turbidity at 30 second intervals for 4 minutes
      623 Record the maximum reading obtained in the 4 minute period
6 3    Preparation of calibration curve
      6 3 1  Prepare calibration curve using standard sulfate solution (5 4)
      632 Space standards at 5 mg/1 increments in the 0-40 mg/1 sulfate range
                                    375 4-2
                                                                                        	i

-------
          633 Above 50 mg/1 the accuracy decreases and the suspensions lose stabilityi
          634 Check reliability of calibration curve by running a standard with every 3 or 4
               samples
     6 4   Correction for sample color and turbidity
          6 4 1 Run a sample blank using the proceduie 6 1 and 6.2 without the addition of barium
               chloride (6 14)
     Calculations
     7 1   Read mg SO4 from calibration curve
                           mg SO4/1 =  mgSO4 x 1,000
                                          ml sample


     Precision and Accuracy
     8 1   Thirty-four analysts in 16 laboratories analyzed six synthetic water samples containing
          exact increments of inorganic sulfate with the following results-
      Increment as
         Sulfate
        mg/liter

           86
           92
           110
           122
           188
           199
   Precision as
Standard Deviation
     mg/liter

       230
       178
       786
       750
       958
       118
          Accuracy as
 Bias,
 -372
 -8.26
 -301
 -337
+004
 -170
  Bias
mg/liter

  -03
  -08
  -33
  -41
 +01
  -34
(FWPCA Method Study 1, Mineral and Physical Analyses)
     82   A synthetic unknown sample containing 259 mg/1 sulfate, 108 mg/1 Ca, 82 mg/1 Mg,
           3 1 mg/1 K,  19 9 mg/1 Na, 241 mg/1 chloride, 0 250 mg/1 nitrite N, 1 1 mg/1 nitrate
           N, and  42 5 mg/1  total alkalinity  (contributed by NaHCO3) was  analyzed in  19
           laboratories by the turbidimetnc method, with a relative standard deviation of 9 1% and
           a relative error of 1 2%

                                       Bibliography

1    Annual Book  of ASTM Standards, Part 31, "Water", Standard D5 16-68, Method B, p 430
     (1976)
2    Standard Methods for the Examination of Water and Wastewater, 14th  Edition, p 496,
     Method 427C, (1975)
                                         375.4-3

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                                       SULFIDE

                         Method  376.1  (Titrimetric, Iodine)

                                                          STORET NO. Total 00745
                                                                       Dissolved 00746

1    Scope and Application
     1 1  This method is applicable to the measurement of total and dissolved sulfides in drinking,
          surface and saline waters, domestic and industrial wastes
     1 2  Acid insoluble sulfides are not measured by the use of this test (Copper sulfide is the only
          common sulfide in this class)
     1 3  This method is suitable for the measurement of sulfide in concentrations above 1 mg/1
2    Summary of Method
     2 1  Excess iodine is added to a sample which may or may not have been treated with zinc
          acetate to produce zinc sulfide The iodine oxidizes the sulfide to sulfur under acidic
          conditions The excess iodine  is backtitrated with sodium thiosulfate  or phenylarsine
          oxide
3    Comments
     3 1  Reduced  sulfur compounds,  such as  sulfite,  thiosulfate and  hydrosulfite, which
          decompose in acid may yield erratic results Also, volatile iodine-consuming substances
          will give high results
     3 2  Samples must be taken with  a minimum of aeration  Sulfide may be  volatilized by
          aeration and any oxygen inadvertently added to the sample may convert the sulfide to an
          unmeasurable form
     33   If the sample is not preserved with zinc acetate and NaOH, the analysis must be started
           immediately Similarly, the measurement of dissolved sulfides mut also be commenced
           immediately
4    Apparatus Ordinary laboratory glassware
5    Reagents
     5 1  Hydrochloric acid, HC1,6 N
     5 2  Standard iodine solution,  0 0250 N Dissolve 20 to 25 g KI in a little water in a liter
          volumetric and add 3 2 g iodine  Allow to dissolve Dilute to 1 liter and standardize
          against 0 0250 N sodium thiosulfate or phenylarsine oxide using a starch indicator
     5 3  Phenylarsine oxide 0 0250 N commercially available
     5 4  Starch indicator commercially available
     5 5  Procedure for standardization (see Residual  Chlonne-iodometnc titration Method
           330 3, section 5 15)
Approved for NPDES
Issued 1971
Editorial revision 1978

                                         376 1-1

-------
      Procedure
      6 1   Unprecipitated sample
           6 1 1  Place a known amount of standard iodine solution (5 2) into a 500 ml flask The
                 amount should be estimated to be in excess of the amount of sulfide expected
           612  Add distilled water, if necessary, to bring the volume to approximately 20 ml
           6 1 3  Add2mlof6NHCl(5 1)
           6 1 4  Pipet 200 ml of sample into the flask, keeping the tip of the pipet below the surface
                 of the sample
           615  If the iodine color disappears, add more iodine until the color remains Record the
                 total number of millihters of standard iodine used in performing steps 611 and
                 615
           6 1 6  Titrate  with the reducing solution (0 0250 N sodium thiosulfate or  0 0250 N
                 phenylarsme oxide solution (5 3)) using a starch indicator (5 4) until the blue color
                 disappears Record the number of millihters used
      6 2   Precipitated samples
           621  Add the reagents to the sample in the original bottle Perform steps 611,613,
                 6 1  5, and 6 1 6
      6 3   Dewatered samples
           6 3 1  Return the glass fibre filter paper which contains the sample to the original bottle
                 Add 200 ml distilled water  Perform steps 6 1 1,6  1 3, 6 1 5, and 6 1 6
           632  The calculations (7) should be based on the volume of original sample put through
                 the filter
      Calculations
      7.1   One ml of 0 0250 N standard iodine solution (5 2) reacts with 0 4 mg of sulfide present in
           the titration vessel
      7 2   Use the formula
                             mg/1 sulfide =  400 (A - B)
                                              ml sample
     where
     A = ml of 0 0250 Nstandard iodine solution (5 2)
     B = ml of 0 0250N standard reducing sodium thosulfate or phenylarsme oxide)
          solution (5 3)
8.    Precision and Accuracy
     8 1   Precision and accuracy for this method have not been determined

                                       Bibliography

1    Standard  Methods for the Examination of Water and Wastewater, 14th  Edition, p 505,
     Method 428D, (1975)
                                          376 1-2

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                                      SULFIDE

                   Method 376.2 (Colorimetric, Methylene  Blue)

                                                         STORET  NO.  Total  00745
                                                                      Dissolved  00746

     Scope and Application
     1 1  This method is applicable to the measurement of total and dissolved sulfides in drinking,
          surface and saline waters, domestic and industrial wastes
     1 2  Acid  insoluble sulfides are not measured by this method  Copper sulfide is the only
          common sulfide in this class
     1 3  The method is suitable for the measurement of sulfide in concentrations up to 20 mg/1
     Summary of Method
     2 1  Sulfide reacts with  dimethyl-p-phenylenediamme (p-ammodimethyl aniline)  in the
          presence of ferric chloride to produce methylene blue, a dye which is measured at a
          wavelength maximum of 625 nm,
     Comments
     3 1  Samples must be taken with a minimum  of aeration  Sulfide may  be volatilized  by
          aeration and any oxygen inadvertently added to the sample may convert the sulfide to an
          unmeasurable form Dissolved oxygen should not be present in any water used to dilute
          standards
     3 2  The analysis must be started immediately
     3 3  Color and turbidity  may interfere with observations of color  or  with photometric
          readings
     Apparatus
     4 1  Matched test tubes, approximately 125 mm long and 15 mm O D
     4 2  Droppers, delivering 20 drops/ml To obtain uniform drops, hold dropper in vertical
          position and allow drops to form slowly
     4 3  Photometer, use either 43 1 or 4 3 2
          431  Spectrophotometer, for use at 625 nm with cells of 1 cm and 10 cm light path
          432  Filter photometer, with filter providing transmittance near 625 nm
     Reagents
     5 1  Ammo-sulfunc acid stock solution Dissolve 27 g N,N-dimethyl-p-phenylenediamme
          oxalate (p-aminodimethylanihne) in a cold mixture of 50 ml cone  H2SO4 and 20 ml
          distilled water in a 100 ml volumetric flask Cool and dilute to the mark  If dark discard
          and purchase fresh reagent Store in dark glass bottle
     5 2  Ammo-sulfunc acid reagent Dissolve 25 ml amino-sulfunc acid stock solution (5  1) with
          975 ml of 1 +1 H2SO4 (5 4) Store in a dark glass bottle  This solution should be clear
     5 3  Ferric chloride solution Dissolve 100 g FeCl36H2O in 40 ml distilled water
Approved for  NPDES
Issued 1978

                                         376 2-1

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 5 4   Sulfunc acid solution, H2SO4,1 +1
 5.5   Diammomum hydrogen phosphate solution  Dissolve 400 g (NH4)2HPO4 m  800 ml
      distilled water
 5 6   Methylene blue solution I Dissolve 1 0 g of methylene blue in distilled water m a 1 liter
      volumetric flask and dilute to the mark Use U S P grade or one certified by the
      Biological Stain Commission The dye content reported on the label should be 84% or
      more  Standardize (5 8) against  sulfide solutions of known  strength  and  adjust
      concentration so that 0 05 ml (1 drop) equals 1 0 mg/1 sulfide
 5 7   Methylene blue solution II Dilute 10 00 ml of adjusted methylene blue solution I (5 6) to
      100 ml with distilled water in a volumetric flask
 5 8   Standardization of methylene blue I solution
      581 Place several  grams of clean, washed crystals of sodium sulfide Na2S9H2O m a
           small beaker
      582 Add somewhat less than enough water to  cover the crystals
      583 Stir occasionally for a few minutes  Pour the solution into another vessel This
           reacts slowly with oxygen but the change is insigmficnat over a few hours Make
           the solution daily
      5.8 4 To 1 liter of distilled water add 1 drop of solution and mix
      5.8 5 Immediately determine the sulfide concentration by the methylene blue procedure
           (6) and by the titrimetnc iodide procedure (Method 376 1, this manual)
      586 Repeat using more than one drop of sulfide solution or less water until at least five
           tests have been made in the range of 1 to 8 mg/1 sulfide
      587 Calculate the average percent error of the  methylene blue procedure (6)  as
           compared to the titnmetnc iodide procedure (Method 376  1)
      588 Adjust by dilution or by adding more dye  to methylene blue solution I (5 6)
Procedure
6 1    Color development
      6.1 1  Transfer 7 5 ml of sample to each of two matched test tubes using a special wide
           tipped pipet or filling to a mark on the test tubes
     6 1 2 To tube A add 0 5 ml amine-sulfunc acid  reagent (5 2) and 0 15 ml (3 drops) FeCl3
          solution (5  3)
      613  Mix immediately by inverting the tube only once
      6 1 4 To tube B add 0 5 ml 1 +1 H2SO4 (5 4) and 0 15 ml (3 drops) FeCl3 solution (5 3)
          and mix
      6.1 5 Color will develop  in tube A in the presence of sulfide Color development is
          usually complete in about 1 minute, but a longer time is often required for the
          fading of the initial pink color
     6.1 6 Wait 3 to 5 minutes
     6 1 7 Add 1 6 ml (NH4)2HPO4 solution (5 5) to each tube
     6 1.8 Wait 3 to 5 minutes and make color comparisons If zinc acetate was used wait at
          least 10 minutes before making comparison
                                    376 2-2

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6 2  Color comparison
           6 2 1 Visual
                6211     Add methylene blue solution I (5 6) and/or II (5 7) (depending on
                          sulfide concentration and accuracy desired) dropwise to tube B (6 1 4)
                          until the color matches that developed m the first tube
                6212     If the concentration exceeds 20 mg/1, repeat 6211 using a portion of
                          the sample diluted to one tenth
           622 Photometric
                6221     Use a 1 cm cell for 0 1 to 2 0 mg/1  Use a 10 cm cell for up to 20 mg/1
                6222     Zero instrument with portion of sample from tube B (6 1 4)
                6223     Prepare calibration  curve  from  data  obtained  in methylene blue
                          standardization (5 8), plotting concentraton obtained from titnmetric
                          iodide procedure (Method 376 1) versus absorbance A straight line
                          relationship can be assumed from 0 to 1.0 mg/1
                6224     Read the sulfide concentration from the calibration curve
7    Calculations
     7 1   Visual comparison  With methylene blue solution I (5 6), adjusted so that 0 05 ml (1
           drop) =10 mg/1 sulfide and a 7 5 ml sample

           mg/1 sulfide  = number drops methylene blue solution I (5 6) +  0 1 x [number of drops
                          methylene blue solution II (5 7)]
     7 2   Photometric  see 6 2 2 4
8    Precision and Accuracy
     8 1   The precision has not been determined  The accuracy is about 10%

                                      Bibliography

1    Standard Methods  for he Examination of Water and Wastewater, 14th edition, p 503, Method
     428C(1975)
                                         376 2-3

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                                       SULFITE

                             Method 377.1 (Titrimetric)

                                                                 STORET NO. 00740

     Scope and Application
     1 1  This method is applicable to drinking and surface waters, sewage and industrial wastes
          The pnmary application has been to cooling, process and distribution water systems and
          boiler feedwaters to which sulfide is added in order to reduce dissolved oxygen and
          eliminate corrosion
     1 2  The minimum detectable limit is 2-3 mg/1 SO3
     Summary of Method
     2 1  An acidified sample containing a starch indicator is titrated with a standard potassium
          lodide-iodate titrant to a faint permanent blue end point  which appears when the
          reducing power of the sample has been completely exhausted
     Interferences
     3 1  The temperature of the sample must be below 50C
     3 2  Care must be taken to allow as little contact with air as possible For example, do not
          filter the sample  Keep the bure{ tip below the surface of the sample
     3 3  Other oxidizable substances, such as organic compounds,  ferrous iron and sulfide are
          positive  interferences. Sulfide may  be  removed by adding  0 5g of zinc acetate and
          analyzing the supernatant of the settled sample
     3 4  Nitrite gives a negative interference by oxidizing sulfite when the sample is acidified, this
          is corrected by either using a proprietary indicator which eliminates nitrite or by adding
          sulfamic acid
     3 5  Copper and possibly other heavy metals catalyze the oxidation of sulfite, EDTA is used
          to complex metals
     36  A blank must be run to correct for interferences present in the reagents
     Apparatus
     4 1  Standard laboratory glassware is used
     Reagents
     5 1  Sulfunc acid, H2SO4, 1 +1
     5 2  Starch  indicator   Amylose,   Mallmckrodt  Chemical  Works,  Thyodene, Magnus
          Chemical Co or equivalent
     5 3  Dual-Purpose  Sulfite Indicator Powder a proprietary formulation containing sulfamic
          acid to destroy nitrite
     54  Standard potassium lodide-iodate titrant,  Q0125N_ Dissolve  4458  mg anhydrous
          potassium lodate, KIO3 (pnmary standard grade dried for several hours at 120C), 4 25g
Approved for NPDES
Issued 1974
Editorial revision 1978

                                         377 1-1

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      KI and 310 mg NaHCO3 in distilled water and dilute to 1 liter This titrant is equivalent
      to500ugSO3/100ml
 5 5   Sulfamic Acid Crystalline
 5 6   EDTA Reagent Dissolve 2 5g EDTA in 100 ml distilled water
 Procedure
 6 1   Sampling
      Contact with air must be minimized If the sample temperature is greater than 50C, it
      must  be cooled  m a  special  apparatus  described  elswhere  (see Bibliography)
      Immediately add 1 ml of EDTA Solution (5 6) per 100 ml of sample
 6 2   Starch Indicator
      6 2 1 Place 1 ml H2SO4 (5 1) in titration vessel
      622 Add 0 1 g sulfamic acid crystals (5 5)
      623 Add 50 ml sample
      624 Add approximately 0 1 g starch indicator (5 2)
      625 Titrate with potassium lodide-iodate titrant (5 4) until a faint permanent blue color
           develops Keep the pipet tip below the surface of the sample  View the color change
           against a white background Record the ml titrant
      626 Run a reagent blank using distilled water instead of sample (6 2 3)
 6 3   Dual Purpose Sulfite Indicator Powder
      631 Place 50 ml sample in a titration vessel
      632 Add 3-4 drops phenolphthalem indicator
      633 Add sufficient scoops (Ig) of indicator (5 3) to discharge the red color
      634 Titrate with potassium lodide-iodate titrant (5 4) until a faint permanent blue color
           develops View the color change against  a white background Record the ml
           titrant
      635 Run a reagent blank using distilled water instead of sample (6 3 1)
 Calculations
 7 1    Use the formula
                       mg/lS03=AxfJx4i)'000
                                     ml sample
     where
     A = ml titrant (6 2 5 or 6 3 4) B = ml
     B = ml titrant for the blank (6 2 6 or 6 3 5) and
     N = normality of KI-KIO3 titrant (5 4)
72  To calculate as Na2SO3
     mg/1 Na2SO3 = mg/1 SO3 x 1 57
Precision and Accuracy
8 1  Precision and accuracy data are not available at this time
                                    377 1-2

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                                     Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D1339-72, Method C, p 440
     (1976)
2    Standard Methods  for the Examination of Water and Wastewater, 14th Edition, p 508,
     Method 429, (1975)
                                        377 1-3

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                      BIOCHEMICAL OXYGEN DEMAND

                           Method 405.1  (5 Days, 20C)

                                                                STORET NO. 00310
                                                                Carbonaceous 80082
     Scope and Application
     1 1  The biochemical oxygen demand (BOD) test is used for determining the relative oxygen
          requirements of municipal and industrial wastewaters Application of the test to organic
          waste discharges allows calculation of the effect of  the  discharges on the oxygen
          resources of the receiving water  Data from BOD tests are used for the development of
          engineering criteria for the design of wastewater treatment plants
     1 2  The BOD test is an empirical bioassay-type procedure which measures the dissolved
          oxygen consumed by microbial life while assimilating and oxidizing the organic matter
          present  The standard test conditions include dark incubation at 20C for a specified time
          period (often 5 days)  The actual environmental conditions of temperature, biological
          population, water movement, sunlight,  and oxygen concentration cannot be  accurately
          reproduced in the laboratory Results obtained must take into account the above factors
          when relating BOD results to stream oxygen demands
     Summary of Method
     2 1  The sample of waste, or an appropriate dilution, is incubated for 5 days at 20C in the
          dark The reduction in dissolved oxygen concentration during the incubation period
          yields a measure of the biochemical oxygen demand
     Comments
     3 1  Determination of dissolved oxygen in the BOD test may be made by use of either the
          Modified Wmkler with Full-Bottle Technique or the Probe Method in this manual
     3 2  Additional information relating to oxygen demanding characteristics of wastewaters can
          be gained by applying the Total Organic Carbon and Chemical Oxygen Demand tests
          (also found in this manual)
     3 3  The use of 60 ml incubation bottles m  place of the usual 300 ml incubation  bottles, in
          conjunction with the probe, is often convenient
     Precision and Accuracy
     4 1  Eighty-six analysts in fifty-eight laboratories analyzed natural water samples plus an
          exact increment of biodegradable organic compounds  At a mean value of 2  1 and 175
          mg/1 BOD, the standard deviation was  0 7 and 26 mg/1, respectively (EPA Method
          Research Study 3)
     4 2  There is no acceptable procedure for determining the accuracy of the BOD test
Approved for NPDES  CBOD  pending approval for Section 304(h), CWA
Issued 1971
Editorial revision 1974

                                        405 1-1

-------
 5    References
5 1    The procedure to be used for this determination is found in
      Standard Methods for the Examination of Water and Wastewater, 15th
      Edition, p 483, Method 507 (1980)
5 2    Young, J  C, "Chemical Methods for Nitrification Control," J Water
      Poll Control Fed, 45, p 637 (1973)
                                  405 1-2

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                        CHEMICAL  OXYGEN DEMAND

                      Method 410.1 (Titrimetric,  Mid-Level)

                                                                STORET NO. 00340

i    Scope and Application
     1 1   The Chemical Oxygen Demand (COD) method determines the quantity of oxygen
          required to oxidize the organic matter in a waste sample, under specific conditions of
          oxidizing agent, temperature, and time
     1 2   Since the test utilizes a specific chemical oxidation the result has no definite relationship
          to the Biochemical Oxygen Demand (BOD) of the waste or to the Total Organic Carbon
          (TOC) level The test result should be considered as an independent measurement of
          organic matter in the sample, rather than as a substitute for the BOD or TOC test
     1 3   The method can be applied to domestic and industrial waste samples having an organic
          carbon concentration greater than 50 mg/1  For lower concentrations of carbon such as
          in surface water samples, the Low Level Modification should be used When the chloride
          concentration of the sample exceeds 2000 mg/1, the modification for saline  waters is
          required
2    Summary of Method
     2 1   Organic and oxidizable inorganic substances nxthe sample are oxidized by potassium
          dichromate in 50% sulfunc acid solution at reflux temperature Silver sulfate is used as a
          catalyst  and mercuric sulfate is added to remove chloride  interference The excess
          dichromate   is   titrated  with  standard   ferrous   ammonium   sulfate,   using
          orthophenanthrolme ferrous complex as an indicator
3    Sampling and Preservation
     3 1   Collect the samples in glass bottles, if possible  Use of plastic containers is permissible if it
          is known that no organic contaminants are present in the containers
     3 2  Biologically active samples should be tested as soon as possible  Samples containing
          settleable material should be well mixed, preferably homogenized, to permit removal of
          representative aliquots
     3 3   Samples should be preserved with sulfunc acid to a pH  < 2 and maintained at 4C until
          analysis
4    Interferences
     4 1   Traces of organic material either from the glassware or atmosphere may cause a gross,
          positive error
          411  Extreme care should be exercised to avoid inclusion of organic materials in the
                distilled water used for reagent preparation or sample dilution
          412 Glassware used in the test should be conditioned by running blank procedures to
                eliminate traces of organic material

Approved for NPDES
Issued 1971
Editorial revision  1978

                                         410 1-1

-------
     4 2   Volatile materials may be lost when the sample temperature rises during the sulfunc acid
           addition step To minimize this loss the flask should be cooled during addition of the
           sulfunc acid solution
     4 3   Chlorides  are  quantitatively  oxidized  by  dichromate  and  represent  a positive
           interference  Mercuric sulfate is added to the digestion flask to complex the chlorides,
           thereby effectively eliminating the interference on all but brine and estuarme samples
5.   Apparatus
     5 1   Reflux apparatus Glassware should consist of a  500 ml Erlenmeyer flask or a 300 ml
           round bottom flask made of heat-resistant glass connected to a 12 inch Alhhn condenser
           by means of a ground glass joint Any equivalent reflex apparatus may be  substituted
           provided that a ground-glass connection is used between the flask and the condenser
6    Reagents
     6.1   Distilled water Special precautions should be taken to insure that distilled water used in
           this test be low in organic matter
     6 2   Standard potassium dichromate solution (0 250 N) Dissolve 12 259 g K2Cr2O7, primary
           standard grade, previously dried at 103C for two hours, in distilled water and dilute to
           1000ml
     6 3   Sulfunc acid reagent  Cone H2SO4 containing 23 5g silver sulfate, Ag2SO4,  per 4 09kg
           bottle With continuous stirnng, the silver sulfate  may be dissolved m about 30 minutes
     6.4   Standard ferrous ammonium sulfate (0 25 N) Dissolve 98 0 g of Fe(NH4)2(SO4)26H2O
           in distilled water Add 20 ml of cone  H2SO4 (6 8),  cool and dilute to 1 liter This solution
           must be standardized daily against standard K2Cr2O7 solution (6 2)
           641 Standardization To approximately 200 ml of distilled water add 25 0 ml of 0 25 N
                K2Cr2O7 (6 2) solution Add 20  ml of H2SO4 (6 8) and cool Titrate with ferrous
                ammonium sulfate (6 4) using 3 drops of ferroin indicator (66)  The color change
                is sharp, going from blue-green to reddish-brown
                Normality = (ml K2Cr2O,)(0 25)
                             ml Fe (NH<)2 (SO,)2

     6.5  Mercunc sulfate Powdered HgSO4
     6.6  Phenanthrolme ferrous sulfate (ferroin) indicator  solution Dissolve 1 48 g of 1-10
           (ortho) phenanthrohne monohydrate, together with 0 70 g of FeSO47H2O in 100 ml of
           water This indicator may be purchased already prepared
     67  Sliver sulfate Powdered Ag2SO4
     6.8  Sulfunc acid (sp  gr 1 84) Concentrated H2SO4
     Procedure
     7 1  Place several boiling stones in the reflux flask, followed by 50 0 ml of sample or an
          aliquot diluted to 50 0 ml and 1 g of HgSO4 (6 5) Add 5 0 ml cone  H2SO4 (6 8), swirl
          until the mercunc sulfate has dissolved Place reflux flask in an ice bath and slowly add,
          With swirling, 25 0 ml of 0 25 N K2Cr2O7 (6 2)  Now add 70 ml of sulfunc acid-silver
                                         410 1-2

-------
           sulfate solution (6 3) to the cooled reflux flask, again using slow addition with swirling
           motion
           Caution Care must be taken to assure that the contents of the flask are well mixed If not,
           superheating may result, and the mixture may be blown out of the open end of the
           condenser
           7 1 1 If volatile orgamcs are present in the sample, use an allihn condenser and add the
                sulfunc acid-silver sulfate solution through the condenser, while cooling the flask,
                to reduce loss by volatilization
     7 2   Apply heat to the flask and reflux for 2 hours For some waste waters, the 2-hour reflux
           period is not necessary  The time required to give the maximum oxidation for a
           wastewater of constant or known composition may be determined and a shorter period of
           refluxing may be permissible
     7 3   Allow the flask to cool and wash down the condenser with about 25 ml of distilled water
           If a round bottom flask has been used, transfer the mixture to a 500 ml Erlenmeyer flask,
           washing out the reflux flask 3 or 4 times with distilled water Dilute the acid solution to
           about 300 ml with distilled water and allow the solution to  cool  to  about  room
           temperature  Add 8 to 10 drops of ferrom indicator (6 6) to the solution and titrate the
           excess dichromate with 0 25 N ferrous ammonium sulfate (6 4) solution to the end point
           The color change will be sharp, changing from a blue-green to a reddish hue
     7 4   Blank-Simultaneously run a blank determination following the details given in (7 1) and
           (7 2), but using low COD water in place of sample
     Calculation
     8 1   Calculate the COD in the sample in mg/1 as follows
                              COD,  mg/liter = (A - B)N x 8,000
                                                        S

                where
                A = milhliters of Fe(NH4)2(SO4)2 solution required for titration of the blank,
                B = milhliters of Fe(NH4)2 (SO4)2 solution required for titration of the sample,
                N = normality of the Fe(NH4)2(SO4)2 solution, and
                S = milhliters of sample used for the test
9    Precision and Accuracy
     9 1   Eighty-six analysts m  fifty-eight laboratories  analyzed  a  distilled water  solution
           containing oxidizable organic material equivalent to 270  mg/1 COD  The standard
           deviation was 17 76 mg/1  COD with an accuracy as  percent relative error (bias) of
           -4 7% (EPA Method Research Study 3)

                                       Bibliography

1    Standard  Methods for the Examination of Water and Wastewater, 14th Edition,  p 550,
     Method 508 (1975)
2    Annual Book of ASTM Standards, Part 31, "Water", Standard D1252-67, p 473 (1976)
                                         410 1-3

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                         CHEMICAL  OXYGEN DEMAND

                       Method  410.2  (Titrimetric, Low Level)

                                                                 STORET NO.  00335

 1     Scope and Application
      1 1   The scope of this modification of the Chemical Oxygen Demand (COD) test is the same
           as for the high level test It is applicable to the analysis of surface waters, domestic and
           industrial wastes with low demand characteristics
      1 2   This method (low level) is applicable foi samples having a COD in the range of 5-50
           mg/1 COD
 2     Summary of Method
      2 1   Organic and oxidizable inorganic substances in an aqueous sample are oxidized by
           potassium dichromate solution in 50 percent (by volume) sulfunc acid in solution  The
           excess  dichromate  is  titrated with  standard ferrous  ammonium sulfate  using
           orthophenanthrolme ferrous complex (ferrom) as an indicator
 3     Sampling and Preservation
      3 1   Collect the samples in glass bottles, if possible Use of plastic containers is permissible if it
           is known that no organic contaminants are present in the containers
      3 2   Biologically active samples should be tested as soon as possible Samples containing
           settleable material should be well mixed, preferably homogenized, to permit removal of
           representative ahquots
      3 3   Samples should be preserved with sulfunc acid to a pH < 2 and maintained at 4C until
           analysis
4     Interferences
      4 1   Traces of organic material either from the glassware or atmosphere may cause a gross,
           positive error
           411 Extreme  care should be exercised to avoid  inclusion of organic materials  in the
                distilled water used for reagent preparation or sample dilution
           412 Glassware used in the test should be conditioned by running blank procedures to
                eliminate traces of organic material
      4 2   Volatile materials may be lost when the sample temperature rises during the sulfunc acid
           addition step
      4 3   Chlorides  are  quantitatively oxidized  by  dichromate and  represent  a  positive
           interference Mercunc sulfate is added to the digestion flask to complex the chlondes,
           thereby effectively eliminating the interference on all but bnne and estuanne samples
5     Apparatus
      5 1   Reflux apparatus Glassware should consist of a 500 ml Erlenmeyer flask or a 300 ml
           round bottom flask made of heat-resistant glass connected to a 12 inch Alhhn condenser


Issued 1971
Editorial revision 1974 and 1978

                                         4102-1

-------
      by means of a ground glass joint  Any equivalent reflux apparatus may be substituted
      provided that a ground-glass connection is used between the flask and the condenser
Reagents
6 1   Distilled water Special precautions should be taken to insure that distilled water used in
      this test be low m organic matter
6 2   Standard potassium dichromate solution (0 025 N) Dissolve 12 259 g K2Cr2O7, primary
      standard grade, previously dried at 103C for two hours, m distilled water and dilute to
      1000 ml Mix this solution thoroughly then dilute  100 0 ml to 1000 ml with distilled
      water.
6 3   Sulfunc acid reagent  Cone H2SO4 containing 23 5g silver sulfate, Ag2SO4, per 4 09kg
      bottle (With  continuous stirring, the silver sulfate may be  dissolved m  about 30
      minutes )
6 4   Standard ferrous ammonium sulfate (0 025 N) Dissolve 98 g of Fe(NH4)2(SO4)26H2O in
      distilled water Add 20 ml of cone H2SO4 (6 8), cool and dilute to 1 liter Dilute 100 ml of
      this  solution to  1 liter with distilled water  This solution must be standardized daily
      against K2Cr2O7 solution
      6 4 1 Standardization To approximately 200 ml of distilled water add 25 0 ml of 0 025 N
           K2Cr2O7 (6 2) solution  Add 20 ml of H2SO4 (6 8) and cool Titrate with ferrous
           ammonium sulfate (6 4) using 3 drops of ferroin indicator (6 6)  The color change
           is sharp, going from blue-green to reddish-brown

                                              K,Cr2O7)(0 025)
                                          ml Fe (NH4)2 (SO4)2
65  Mercuric sulfate Powdered HgSO4
6 6  Phenanthrohne ferrous sulfate (ferroin) indicator solution Dissolve 1 48 g of 1-10
     (ortho)phenanthrolme monohydrate, together with 0 70 g of FeSO47H2O in 100 ml of
     water This indicator may be purchased already prepared
6 7  Silver sulfate Powdered Ag2SO4
6.8  Sulfunc acid (sp gr 1 84)  Concentrated H2SO4
Procedure
7 1  Place several boiling stones m the reflux flask, followed by 50 0 ml of sample or an
     aliquot diluted to 50 0 ml and 1 g of HgSO4 (6 5) Add 5 0 ml cone  H2SO4 (6 8), swirl
     until the mercuric sulfate has dissolved  Place reflux flask m an ice bath and slowly add,
     with swirling, 25 0 ml of 0 025 N K2Cr2O7 (6 2) Now add 70 ml of sulfunc acid-silver
     sulfate solution (6 3) to the cooled reflux flask, again using slow addition with swirling
     motion
     Caution  Care must be taken to assure that the contents of the flask are well mixed  If not,
     superheating may  result, and the mixture may be blown out  of the open end  of the
     condenser
                                    410 2-2

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     71,1 If volatile orgamcs are present in the sample, use an Allihn condenser and add the
           sulfunc acid-silver sulfate solution through the condenser, while cooling the flask,
           to reduce loss by volatilization
7 2  Apply heat to the flask and reflux for 2 hours  For some waste waters, the 2-hour reflux
     period is not necessary The time required to give the maximum oxidation for a
     wastewater of constant or known composition may be determined and a shorter period of
     refluxing may be permissible
7 3  Allow the flask to cool and wash down the condenser with about 25 ml of distilled water
     If a round bottom flask has been used, transfer the mixture to a 500 ml Erlenmeyer flask,
     washing out the reflux flask 3 or 4 times with distilled water Dilute the acid solution to
     about 300 ml with distilled water and allow the solution to cool  to  about room
     temperature  Add 8 to  10 drops of ferroin indicator (6 6) to the solution and titrate the
     excess dichromate with 0 025 N  ferrous ammonium sulfate (6 4) solution to the end
     point The color change will be sharp, changing from a blue-green to a reddish hue
7 4  BlankSimultaneously run a blank determination following the details given in  (7 1)
     and (7 2), but using low COD water in place of sample
Calculation
8 1  Calculate the COD in the sample in mg/1 as follows
                          COD, mg/1 = (A ~ B)N x 8,000
                                               O
           where
           A = millihters of Fe(NH4)2(SO4)2 solution required for titration of the blank,
           B = millihters of Fe(NH4)2(SO4)2 solution required for titration of the sample,
           N = normality of the Fe(NH4)2(SO4)2 solution, and
           S = millihters of sample used for the test

Precision and Accuracy
9 1   Eighty-six analysts  in fifty-eight laboratories analyzed  a distilled  water solution
     containing oxidizable organic  material equivalent to 12 3 mg/1 COD  The standard
     deviation  was 4 15 mg/1 COD  with an  accuracy as percent relative error (bias) of
     0 3% (EPA Method Research Study 3 )
                                     410 2-3

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                       CHEMICAL OXYGEN  DEMAND

          Method 410.3 (Titrimetric,  High Level  for Saline Waters)

                                                                STORET  NO.  00340

    Scope and Application
    1 1   When the chloride level exceeds 1000 mg/1 the minimum accepted value for the COD
          will be 250 mg/1  COD levels which fall below this value are highly questionable because
          of the high chloride correction which must be made
    Summary of Method
    2 1   Organic and oxidizable inorganic substances in an aqueous  sample are  oxidized by
          potassium dichromate solution in  50 percent (by volume) sulfunc acid solution  The
          excess  dichromate  is  titrated with  standard  ferrous  ammonium  sulfate using
          orthophenanthrolme ferrous complex (ferroin) as an indicator
    Sample Handling and Preservation
    3 1   Collect the samples in glass bottles, if possible Use of plastic containers is permissible if it
          is known that no organic contaminants are present in the containers
    3 2   Biologically  active samples should be tested as soon  as possible  Samples containing
          settleable material should be well mixed, preferably homogenized, to  permit removal of
          representative ahquots
    3 3   Samples should be preserved with sulfunc acid to a pH < 2 and maintained at 4C until
          analysis
    Interferences
    4 1   Traces of organic material either from the glassware or atmosphere may cause a gross,
          positive error
          411  Extreme care should be exercised to avoid inclusion of organic materials in the
                distilled water used for reagent preparation or sample dilution
          412 Glassware  used in the test should be conditioned by running blank procedures to
                eliminate traces of organic material
     4 2   Volatile materials may be lost when the sample temperature rises during the sulfunc acid
          addition step
     43   Chlorides are  quantitatively  oxidized  by dichromate  and represent a  positive
          interference A chloride correction is made using the  procedure outlined in 7 7 of this
          method
     Apparatus
     5 1   Reflux apparatus Glassware should consist of a 500 ml Erlenmeyer flask or a 300 ml
          round bottom flask made of heat-resistant glass connected to a 12 inch Allihn condenser
          by means of a ground glass joint  Any equivalent reflux apparatus may be substituted
          provided that a ground-glass connection is used between the flask and the condenser
Issued 1971
Editorial revision 1978

                                          4103-1

-------
      Reagents
      6 1   Standard potassium dichromate solution, (0 25 N)  Dissolve  12 2588 g of K2Cr2O7,
           primary standard grade, previously dried for 2 hours at 103C m water and dilute to 1000
           ml
      6 2   Sulfunc acid reagent  Cone  H2SO4 containing 23 5 g silver sulfate, Ag2SO4, per 4 09kg
           bottle  (With continuous stirring,  the  silver sulfate may be  dissolved m about 30
           minutes )
      6 3   Standard ferrous ammonium sulfate, 0 250 N  Dissolve 98 g of Fe(NH4)2(SO4)26H2O in
           distilled water Add 20 ml of cone H2SO4, (6 7), cool and dilute to 1 liter This  solution
           must be standardized against the standard potassium dichromate solution (61) daily
           631 Standardization Dilute 25 0 ml of standard dichromate solution (6 1) to about 250
                ml with distilled water Add 20 ml cone  sulfunc acid  (6 7)  Cool, then titrate with
                ferrous ammonium sulfate titrant (6 3), using 10 drops of ferroin indicator (6 5)


                                  Normality =
                                       dluy
                                              ml Fe(NH4)2 (S04)2
     6 4   Mercuric sulfate  Powdered HgSO4
     6 5   Phenanthrolme ferrous sulfate (ferroin) indicator solution  Dissolve 1 48 g of 1-10-
           (ortho) phenanthrohne monohydrate, together with 0 70 g of FeSO47H2O m 100 ml of
           water This indicator may be purchased already prepared
     66   Silver sulfate Powdered Ag2SO4
     6 7   Sulfunc acid (sp gr 1 84)  Concentrated H2SO4
7.    Procedure
     7 1   Pipet a 50 0 ml aliquot of sample not to exceed 800 mg/1 of COD into a 500 ml, flat
           bottom, Erlenmeyer flask Add HgSO4 (6 4) in the ratio of 10 mg to 1 mg chloride, based
           upon the mg of chloride in the sample aliquot and 5 ml of sulfunc acid (6 7) Swirl until
           all the mercunc sulfate has dissolved Add 25 0 ml of 0 25N K2Cr2O7 (6 1)  Carefully add
           70 ml of sulfunc  acid-silver sulfate solution (6 2) and gently swirl until the solution is
           thoroughly mixed  Glass beads should be added to  the reflux mixture to prevent
           bumping, which can be severe and dangerous
           Caution The reflux mixture must be thoroughly mixed before heat is applied If this is
           not done, local  heating occurs in the bottom of the flask, and the mixture may be blown
           out of the condenser
           711 If volatile organics are present in the sample, use an Allihn condenser and add the
                sulfunc acid-silver sulfate solution through the condenser, while cooling the flask,
                to reduce  loss by volatilization
     7 2   Attach the flask to the condenser and reflux the mixture for two hours
     7 3   Cool, and  wash down the interior of the condenser with 25  ml of distilled water
          Disconnect the  condenser and wash the flask and condenser joint with 25 ml of distilled
          water so that the total volume is 350 ml Cool to room temperature
                                         410 3-2

-------
7 4  Titrate with standard ferrous ammonium sulfate (6 3) using 10 drops of ferrom (6 5)
     indicator  (This amount must not vary from blank, sample and standardization ) The
     color change is sharp, going from blue-green to reddish-brown and should be taken as the
     end point although the blue-green color may reappear within minutes
7 5  Run a blank, using 50 ml of distilled water in place of the sample together with all
     reagents and subsequent treatment
7 6  For COD values greater than 800 mg/1, a smaller aliquot of sample should be taken,
     however, the volume should be readjusted to 50 ml with distilled water having a chloride
     concentration equal to the sample
7 7  Chloride correction"'  Prepare a standard curve of COD versus mg/1 of chloride,  using
     sodium chloride solutions of varying concentrations following exactly the procedure
     outlined The chloride interval,  as a minimum should be 4000 mg/1 up to 20,000  mg/1
     chloride Lesser intervals of greater concentrations must be run as per the requirements
     of the data, but in no case must extrapolation be used
Calculation
                      mg/1 COD =  [(A - B)C X 8.000] - SOD
                                          ml of sample
 where
A = ml Fe(NH4)2(SO4)2 for blank,
B = ml Fe(NH4)2(SO4)2 for sample,
C = normality of Fe(NH4)2(SO4)2,
D = chloride correction from curve (step 7 7)
 12 = compensation factor to account for the extent of chloride oxidation which is dissimilar in
      systems containing organic and non-organic material

Precision and Accuracy
9 1   Precision and accuracy data are not available at this time

                                  Bibliography

Burns, E R , Marshall, C , Journal WPCF, Vol 37, p 1716-1721 (1965)
                                     410 3-3

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                        CHEMICAL OXYGEN  DEMAND

                Method  410.4  (Colorimetric,  Automated; Manual)

                                                                STORET NO. 00340

1    Scope and Application
     1 1  This method covers the determination of COD in surface waters, domestic and industrial
          wastes
     1 2  The applicable range of the automated method is 3-900 mg/1 and the range of the
          manual method is 20 to 900 mg/1
2    Summary of Method
     2 1  Sample, blanks and standards in sealed tubes are heated m an oven or block digester m
          the presence of dichromate at  150C Aftei two hours, the tubes are removed from the
          oven or digester, cooled and measured spectrophotometncally at 600 nm
3    Sample Handling and Preservation
     3 1  Collect the samples in glass bottles if possible  Use of plastic containers is permissible if it
          is known that no organic contaminants are present in the containers
     3 2  Samples should be preserved with sulfunc acid to a pH < 2 and maintained at 4C until
          analysis
4    Interferences
     4 1  Chlorides  are  quantitatively  oxidized  by  dichromate and  represent  a  positive
          interference Mercuric sulfate is added to the digestion tubes to complex the chlorides
5    Apparatus
     5 1  Drying oven or block digestor,  150C
     5 2  Corning culture tubes, 16 x 100 mm or 25 x 150 mm with Teflon lined screw cap
     5 3  Spectrophotometer or Techmcon Auto Analyzer
     5 4  Muffle furnace, 500C
6    Reagents
     6 1  Digestion solution Add 10 2 g K2Cr2O7, 167 ml cone H2SO4 and 33 3 g HgSO4 to 500 ml
          of distilled water, cool and dilute to 1 liter
     6 2   Catalyst solution  Add  22  g  Ag2SO4 to  a  4 09kg bottle of cone  H2SO4   Stir until
           dissolved
     6 3   Sampler wash solution Add 500 ml of cone H2SO4 to 500 ml of distilled water
     6 4   Stock potassium acid phthalate Dissolve 0 850 g m 800 ml of distilled water and dilute to
           1 liter 1 ml =  1 mg COD
           641  Prepare  a  series  of standard solutions  that  cover  the expected sample
                concentrations by diluting appropriate volumes of the stock standard
7    Procedure
     7  1   Wash all culture tubes and screw caps with 20% H2SO4 before their first use to prevent
           contamination Trace contamination may be removed from the tubes by igniting them in
           a muffle oven at 500C for 1 hour

Pending approval for Section 304(h), CWA
Issued 1978
                                         4104-1

-------
      72-  Automated
           721 Add 2 5 ml of sample to the 16 x 100 mm tubes
           722 Add 1 5 ml of digestion solution (61) and mix
           723 Add 3 5 ml of catalyst solution (6 2) carefully down the side of the culture tube
           724 Cap tightly and shake to mix layers
           725 Process standards and blanks exactly as the samples
           726 Place in oven or block digester at 150C for two hours
           727 Cool,  and place standards in sampler in order  of decreasing concentration
                Complete filling sampler tray with unknown samples
           728 Measure color intensity on AutoAnalyzer at 600 nm
      7 3   Manual
           731 The following procedure  may be  used  if a larger  sample is  desired  or  a
                spectrophotometer is used in place of an AutoAnalyzer
           732 Add 10 ml of sample to 25 x 150 mm culture tube
           7.33 Add 6 ml of digestion solution (6 1) and mix
           734 Add 14 ml of catalyst solution (6 2) down the side of culture tube
           735 Cap tightly and shake to mix layers
           736 Place in oven or block digester at 150C for 2 hours
           737 Cool, allow any precipitate to settle and measure intensity in spectrophotometer at
                 600 nm  Use only  optically matched  culture tubes or a single cell for spectro-
                 photometnc measurement
8.    Calculation
      8 1   Prepare a standard curve by plotting peak height or percent transmittance against known
           concentrations of standards
      8 2   Compute concentration of samples by comparing sample response to standard curve
9     Precision and Accuracy
     9 1   Precision and accuracy data are not available at this time

                                     Bibliography

1    Jirka, A M , and M J  Carter, "Micro-Serm-Automated Analysis of Surface and Wastewaters
     for Chemical Oxygen  Demand " Anal Chem  47 1397, (1975)
                                        410 4-2

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                              4104-3

-------
                OIL AND  GREASE, TOTAL,  RECOVERABLE

           Method  413.1 (Gravimetric,  Separatory  Funnel Extraction)

                                                                STORET NO. 00556

1    Scope and Application
     1 1   This method includes the measurement of fluorocarbon-113 extractable matter from
          surface  and saline waters,  industrial  and domestic wastes  It is applicable to  the
          determination of relatively non-volatile hydrocarbons, vegetable oils, animal fats, waxes,
          soaps, greases and related matter
     1 2   The method is not applicable to measurement of light hydrocarbons that volatilize at
          temperatures below 70C Petroleum fuels from  gasoline through #2 fuel oils are
           completely or partially lost in the solvent removal operation
     1 3   Some crude oils and heavy  fuel oils contain a significant percentage of residue-type
          materials that are not soluble in fluorocarbon-113 Accordingly, recoveries of these
          materials will be low
     1 4  The method covers the range from 5 to 1000 mg/1 of extractable material
2    Summary of Method
     2 1   The sample is acidified to a low pH ( < 2) and serially extracted with fluorocarbon-113 in
           a separatory funnel The solvent is evaporated from the extract and the residue weighed
3    Definitions
     3 1    The definition of oil and grease is based on the procedure used The nature of the oil
           and/or grease, and the presence of extractable non-oily matter will influence the material
           measured and interpretation of results
4    Sampling and Storage
     41   A representative sample of 1 liter volume should be collected in a glass bottle If analysis
           is to be delayed for more than a few hours, the sample is preserved by the addition of 5 ml
           HC1 (6 1) at the time of collection and refngeiated at 4C
     4 2   Because losses of grease will occur on sampling equipment, the collection of a composite
           sample is impractical  Individual portions collected at prescribed time intervals must be
           analyzed separately to obtain the average concentration over an extended period
 5    Apparatus
     5 1   Separatory funnel, 2000 ml, with Teflon stopcock
     5 2   Vacuum pump, or other source of vacuum
     5 3   Flask, boiling, 125 ml (Corning No 4100 or equivalent)
     5 4   Distilling head, Claisen or equivalent
     5 5   Filter paper, Whatman No 40,11 cm
 6    Reagents
      6 1   Hydrochloric acid, 1 1  Mix equal volumes of cone  HC1 and distilled water

 Approved  for NPDES
 Issued 1974
 Editorial revision  1978

                                         413 1-1

-------
      62  Flurocarbon-113,(l,l,2-tnchloro-l,2,2-tnfluoroethane),b p 48C
      6 3  Sodium sulfate, anhydrous crystal
7.    Procedure
      7 1  Mark the sample bottle at the water meniscus for later determination of sample volume
           If the sample was not acidified at time of collection, add 5 ml hydrochloric acid (6 1) to
           the sample bottle  After mixing the sample, check the pH by touching pH-sensitive paper
           to the cap to insure that the pH is 2 or lower Add more acid if necessary
      7 2  Pour the sample into a separatory funnel
      7 3  Tare a boiling flask (pre-dned in an oven at 103C and stored m a desiccator)
      7 4  Add 30 ml fluorocarbon-113 (6 2) to the sample bottle and rotate the bottle to rinse the
           sides Transfer the solvent into the separatory funnel Extract by shaking vigorously for 2
           minutes Allow the layers to separate, and filter the solvent layer into the flask through a
           funnel containing solvent moistened filter paper
           NOTE: An emulsion that fails to dissipate  can be broken by pouring about 1 g sodium
           sulfate (6 3) into the filter paper cone and slowly draining the emulsion through the salt
           Additional 1 g portions can be added to the cone as required
      7 5   Repeat (7 4) twice more, with additional portions of fresh solvent, combining all solvent
           in the boiling flask
      7 6   Rinse the tip of the separatory funnel, the filter paper, and then the funnel with a total of
           10-20 ml solvent and collect the rinsings in the flask
      7.7   Connect the boiling flask to the distilling head and evaporate the solvent by immersing
           the lower half of the flask in water at 70C Collect the solvent for reuse A solvent blank
           should accompany each set of samples
      7 8   When the temperature in the distilling head reaches 50C or the flask appears dry remove
           the distilling head  Sweep out the flask for 15 seconds with air to remove solvent vapor by
           inserting a glass tube connected to a vacuum source Immediately remove the flask from
           the heat source and wipe the outside to remove excess moisture and fingerprints
      7 9   Cool the boiling flask in a desiccator for 30 minutes and weigh
8     Calculation
                                     Q 	 T3
      8.1   mg/1 total oil  and grease =    ...
           where

           R = residue, gross weight of extraction flask minus the tare weight, in milligrams
           B  =  blank determination, residue of equivalent  volume  of  extraction solvent, in
                milligrams
           V = volume of sample, determined by refilling sample bottle to calibration line and
                correcting for acid addition if necessary, in liters
                                         413 1-2
                                                              ''1"

-------
9    Precision and Accuracy
     9 1  The two oil and grease methods in this manual were tested by a single laboratory (EMSL)
          on sewage  This method determined the oil and grease level in the sewage to be 126
          mg/1 When 1 liter portions of the sewage were dosed with 14 0 mg of a mixture of #2
          fuel oil and Wesson oil, the recovery was 93% with a standard deviation of 0 9 mg/1

                                      Bibliography

1    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 515,
     Method 502A, (1975)
2    Blum, K A , and Taras, M J , "Determination of Emulsifying Oil m Industrial Wastewater",
     JWPCF Research Suppl 40,R404(1968)
                                         413 1-3

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                OIL AND GREASE, TOTAL RECOVERABLE

                   Method 413.2  (Spectrophotometric, Infrared)

                                                                STORET NO.  00560

1    Scope and Application
     1 1  This method includes the measurement of fluorocarbon-113  extractable matter from
          surface and saline waters, industrial and domestic wastes  It is applicable to the
          determination of hydrocarbons, vegetable oils, animal fats, waxes, soaps, greases and
          related matter
     1 2  The method is applicable to measurement of most light petroleum fuels, although loss of
          about half of any gasoline present during the extraction manipulations can be expected
     1 3  The method covers the range from 0 2 to 1000 mg/1 of extractable material
     1 4  While this method can be used to obtain an estimate of the oil and grease that would be
          measured gravimetncally, in  many cases the estimate  more  accurately describes the
          parameter, as it will measure  volatiles more effectively and is  not susceptible to
          interferences such as extractable sulfur It can be used with the Petroleum Hydrocarbon
          procedure to obtain an oil and grease value and a petroleum hydrocarbon value on the
          same sample
2    Summary of Method
     2 1  The sample is  acidified to a low pH ( < 2) and extracted with fluorocarbon-113  The oil
          and grease is determined by comparison of the infrared absorbance of the sample extract
          with standards
3    Definitions
     3 1  The definition of oil and grease is based on the procedure used The source of the oil
          and/or grease, and the presence of extractable non-oily matter will influence the material
          measured and interpretation of results
4    Sampling and Storage
     41  A representative sample of 1 liter volume should be collected in a glass bottle If analysis
          is to be delayed for more than a few hours, the sample is preserved by the addition of 5 ml
          HC1 (6 1) at the time of collection and refrigerated at 4C
     4 2  Because losses of grease will occur on sampling equipment, the collection of a composite
          sample is impractical Individual portions collected at prescribed time intervals must be
          analyzed separately to obtain the average concentration over an extended period
5    Apparatus
     5 1  Separatory funnel, 2000 ml, with Teflon stopcock
     5 2  Infrared spectrophotometer, scanning Non-scanning instruments may also be used but
          can be subject to positive interferences in complex chemical wastewaters
     5 3  Cells, 10 mm,  50 mm, and 100 mm path length, sodium chloride or infrared grade glass
     5 4  Filter paper, Whatman No 40,11 cm

Issued 1974
Editorial revision 1978

                                         413 2-1

-------
6    Reagents
     6 1   Hydrochloric acid, 1 1 Mix equal volumes of cone HC1 and distilled water
     62   Fluorocarbon-113, (l,l,2-tnchloro-l,2,2-tnfluoroethane),b p 48C
     6 3   Sodium sulfate, anhydrous crystal
     6 4   Calibration mixtures
           641 Reference oil   Pipet 15 0 ml n-hexadecane, 15 0 ml isooctane,  and 100 ml
                chlorobenzene into a 50 ml glass stoppered bottle Maintain the integrity of the
                mixture by keeping stoppered except when withdrawing ahquots
           642 Stock standard   Pipet 1 0 ml reference oil (6 4 1) into a tared 200 ml volumetric
                flask and immediately stopper Weigh and dilute to volume with fluorocarbon-113
           643 Working standards   Pipet appropriate volumes of stock standard (6 4 2) into 100
                ml volumetric flasks according to the cell pathlength to be used Dilute to volume
                with fluorocarbon-113  Calculate concentration of standards  from the  stock
                standard
7.    Procedure
     7 1   Mark the sample bottle at the water meniscus for later determination of sample volume
           If the sample was not acidified at time of collection, add 5 ml hydrochloric acid (6 1) to
           the sample bottle After mixing the sample, check the pH by touching pH-sensitive paper
           to the cap to insure that the pH is 2 or lower Add more acid if necessary
     7 2   Pour the sample into a separatory funnel
     7.3   Add 30 ml fluorocarbon-113 (6 2) to the sample bottle and rotate the bottle to rinse the
           sides Transfer the solvent into the separatory funnel Extract by shaking vigorously for 2
           minutes Allow the layers to separate
     7 4   Filter the solvent layer into a 100 ml volumetric flask through a funnel containing
           solvent-moistened filter paper
           NOTE: An emulsion that fails to dissipate can be broken by pouring about 1 g sodium
           sulfate (6 3) into the filter paper cone and slowly draining the emulsion through the salt
           Additional 1 g portions can be added to the cone as required
     7 5   Repeat  (7 3 and 7 4)  twice more with  30  ml portions of fresh solvent, combining all
           solvent  in the volumetric flask
     7 6   Rinse the tip of the separatory funnel, filter paper, and the funnel with a total of 5-10 ml
           fluorocarbon-113 and collect the rinsings in the flask Dilute the extract to 100 ml, and
           stopper the flask
     7 7   Select appropriate working standards and cell pathlength according to the following
           table of approximate working ranges

                       Pathlength                                     Range

                         10 mm                                     2-40 mg
                        50 mm                                     04-8 mg
                       100 mm                                     0 1-4 mg

     7 8   Scan standards and samples from 3200  cm"1 to 2700 cm"1 with fluorocarbon-113 in the
           reference beam and record the results on absorbance paper The absorbances of samples
                                          413 2-2

-------
           and standards are measured by constructing a straight baseline over the range of the scan
           and measuring the absorbance of the peak maximum at 2930 cm"1 and subtracting the
           baseline absorbance at that point  For an example of a typical oil spectrum and baseline
           construction, see Gruenfeld<3) Non-scanning instruments should be operated according
           to  manufacturer's instructions, although  calibration  must be performed using the
           standards described  above (6 4)  If the absorbance exceeds 0 8 for a sample, select a
           shorter pathlength or dilute as required
     7 9   Use a calibration plot of absorbance vs mg oil prepared from the standards to determine
           the mg oil in the sample solution
     Calculation
     8 1   mg/1 total oil and grease = R *  D
           where

           R = oil in solution, determined from calibration plot, in milligrams
           D = extract dilution factor, if used
           V = volume of sample, determined by refilling sample bottle to calibration line and
                correcting for acid addition if necessary, in liters
9    Precision and Accuracy
     9 1   The two oil and grease methods in this manual were tested by a single laboratory (EMSL)
           on sewage  This method determined the oil and grease level in the sewage to be 17 5
           mg/1  When 1 liter portions of the sewage were dosed with 14 0 mg of a mixture of #2
           fuel oil and Wesson oil, the recovery was 99% with a standard deviation of  1 4 mg/1

                                       Bibliography

1    Standard  Methods for the Examination of Water  and Wastewater,  14th Edition,  p 516,
     Method 502B, (1975)
2    American Petroleum Institute, "Manual on Disposal of Refinery Wastes", Vol IV, Method
     733-58(1958)
3    Gruenfeld, M,  "Extraction of Dispersed Oils from  Water  for Quantitative Analysis  by
     Infrared Spectroscopy", Environ  Sci Technol 7,636(1973)
                                          413 2-3

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                           ORGANIC CARBON, TOTAL

                     Method 415.1  (Combustion or Oxidation)

                                                          STORET NO. Total 00680
                                                                       Dissolved 00681

      Scope and Application
      1 1   This method includes the measurement of organic carbon in drinking, surface and saline
           waters, domestic and industrial wastes  Exclusions are noted under Definitions and
           Interferences
      1 2   The method is most applicable to measurement of organic carbon above 1 mg/1
      Summary of Method
      2 1   Organic carbon in a sample is converted to carbon dioxide (CO2) by catalytic combustion
           or wet chemical oxidation The CO2 formed can be measured directly by an infrared
           detector or converted to methane  (CH4) and measured by a flame lomzation detector
           The amount of CO2 or CH4 is directly proportional to the concentration of carbonaceous
           material in the sample
      Definitions
      3 1   The carbonaceous analyzer measures all of the carbon in a sample Because of various
           properties of carbon-containing compounds in liquid samples, preliminary treatment of
           the sample prior to analysis dictates the definition of the carbon as it is measured Forms
           of carbon that are measured by the method are
           A)   soluble, nonvolatile organic carbon, for instance, natural sugars
           B)   soluble, volatile organic carbon, for instance, mercaptans
           C)   insoluble, partially volatile carbon, for instance, oils
           D)   insoluble, particulate carbonaceous materials, for instance, cellulose fibers
           E)   soluble or insoluble  carbonaceous materials adsorbed or entrapped on insoluble
                inorganic suspended matter, for instance, oily matter adsorbed on silt particles
      3 2   The final usefulness  of the carbon measurement is in assessing the potential oxygen-
           demanding load  of organic material on a  receiving  stream  This statement applies
           whether the carbon measurement is made on a sewage plant effluent, industrial waste, or
           on water taken directly from the stream  In this light, carbonate and bicarbonate carbon
           are not a part of the oxygen demand in the stream and therefore should be discounted in
           the final calculation or removed prior to analysis  The manner of preliminary treatment
           of the sample and instrument settings defines the types of carbon which are measured
           Instrument manufacturer's instructions should be followed
Approved for NPDES
Issued 1971
Editorial revision 1974
                                         415 1-1

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4.   Sample Handling and Preservation
     4 1   Sampling and storage of samples in glass bottles is preferable Sampling and storage in
           plastic bottles such as conventional polyethylene and cubitamers is permissible if it is
           established that the containers do not contribute contaminating organics to the samples
           NOTE 1: A brief study performed in the EPA Laboratory indicated that distilled water
           stored in new, one quart cubitamers did not show any increase in organic carbon after
           two weeks exposure
     4 2   Because of the possibility of oxidation or bacterial decomposition of some components of
           aqueous samples, the lapse of time between collection of samples and start of analysis
           should be  kept to a rrummum Also, samples should be kept cool (4C) and protected
           from sunlight and atmospheric oxygen
     43   In instances where analysis cannot be performed within two hours (2 hours) from time of
           sampling, the sample is acidified (pH < 2) with HC1 or H2SO4
5    Interferences
     5 1   Carbonate and bicarbonate carbon represent an interference under the terms of this test
           and must be removed or accounted for in the final calculation
     5 2   This procedure is applicable only to homogeneous samples which can be injected into the
           apparatus reproducibly by means of a microhter type syringe or pipette The openings of
           the syringe or pipette limit the maximum size of particles which may be included in the
           sample
6    Apparatus
     6 1   Apparatus for blending or homogenizing samples Generally, a Wanng-type blender is
           satisfactory
     6 2   Apparatus for total and dissolved organic carbon
           6 2 1 A  number of companies manufacture systems for  measuring carbonaceous
                material in liquid samples  Considerations should  be made as to  the  types of
                samples to be analyzed, the expected concentration range, and forms of carbon to
                be measured
           622 No specific analyzer is recommended as superior
7,   Reagents
     7 1   Distilled water used in preparation of standards and for dilution of samples should be
           ultra pure to reduce the carbon concentration of the blank Carbon dioxide-free, double
           distilled  water is recommended  Ion exchanged waters are not recommended because of
           the possibilities of contamination with organic materials from the resins
     7 2   Potassium hydrogen phthalate, stock solution, 1000 mg carbon/liter Dissolve  0 2128 g
           of potassium hydrogen phthalate (Primary Standard Grade) in distilled water and dilute
           to 100 0 ml
           NOTE 2- Sodium oxalate and acetic acid are not recommended as stock solutions
     7 3   Potassium hydrogen phthalate, standard solutions Prepare standard solutions from the
           stock solution by dilution with distilled water
     7 4   Carbonate-bicarbonate, stock solution, 1000 mg carbon/liter  Weigh 0 3500 g of sodium
           bicarbonate and 0 4418 g  of sodium carbonate and transfer both to  the same 100 ml
           volumetric flask Dissolve with disulled water
                                          415 1-2

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      7 5   Carbonate-bicarbonate, standard solution Prepare a series of standards similar to step
           73
           NOTE 3: This standard is not required by some instruments
      7 6   Blank solution  Use the same distilled water (or similar quality water) used for the
           preparation of the standard solutions
8     Procedure
      8 1   Follow  instrument  manufacturer's  instructions  for  calibration,  procedure,  and
           calculations
      8 2   For calibration  of the  instrument, it is  recommended that  a series of standards
           encompassing the expected concentration range of the samples be used
9     Precision and Accuracy
      9 1   Twenty-eight analysts in twenty-one laboratories analyzed distilled water solutions
           containing exact increments of oxidizable organic compounds, with the following results

       Increment as             Precision as                          Accuracy as
          TOC             Standard  Deviation              Bias,                  Bias,
        mg/liter              TOC, mg/liter                _%	mg/hter

           49                    393                   +1527                  +075
           107                    832                   +101                  +108

(FWPCA Method Study 3, Demand Analyses)

                                       Bibliography

1     Annual Book of ASTM Standards, Part 31, "Water", Standard D 2574-79, p 469 (1976)
2     Standard Methods for the Examination of Water and Wastewater,  14th Edition, p 532,
      Method 505, (1975)
                                          415 1-3

-------
                                United States
                                Environmental Protection
                                Agency
                                 Environmental Monitoring and
                                 Support Laboratory
                                 Cincinnati OH 45268
                                Research and Development
&EPA
Test  Method
                                Organic Carbon, Total
                                (low  level)
                                (UV promoted,  persulfate
                                oxidation)Method 415.2
                               1   Scope and Application

                               1 1 This method covers the
                               determination of total organic carbon
                               in drinking water and other waters
                               subject to the limitations in 1 3 and
                               5 1

                               1 2 This instrument is designed for
                               a two-step operation to distinguish
                               between purgeable and nonpurgeable
                               organic carbon These separate values
                               are not pertinent to this method

                               1 3 This method is applicable only to
                               the carbonaceous matter which is
                               either soluble or has a particle size of
                               0 2 mm or less

                               1 4 The applicable range is from
                               approximately 50 yug/L to 10 mg /L
                               Higher concentrations may be
                               determined by sample dilution

                               2   Summary of Method
                                A sample is combined with 1  mL of
                               acidified persulfate reagent and
                               placed in a sparger The sample is
                               purged with helium which transfers
                               inorganic  CO2 and purgeable organics
                               to a CO2 scrubber The CO2 is
                               removed with at least 99 9%
                               efficiency  with a 2 5-mmute purge
                               The purgeable organics proceed
                               through a  reduction system where the
                               gas stream is joined by hydrogen and
                               passed over a nickel catalyst which
                               converts the purgeable organic carbon
                               to methane The methane is
                               measured  by a flame lomzation
                               detector  The detector signal is
                               integrated and displayed as the
                               concentration of purgeable organic
                               carbon
                                 The sample is then transferred to a
                               quartz ultraviolet reaction coil where
                               the nonpurgeable organics are
                               subjected to intense ultraviolet
                               illumination in the presence of the
                               acidified persulfate reagent The
                               nonpurgeables are converted to CO2
                               and transferred to a second sparger
                               where a helium purge transfers the
                               COa to the reduction system and into
                               the detector The signal is integrated,
                               added to the purgeable organic carbon
                               value and displayed as the
                               concentration of total organic carbon

                               3   Definitions

                               3 1   Total organic carbon measured
                               by this procedure is the sum of the
                               purgeable organic carbon and the
                               nonpurgeable organic carbon as
                               defined m 3 2 and 3 3

                               3 2  Purgeable organic carbon is the
                               organic carbon matter that is
                               transferred to the gas phase when the
                               sample is  purged with helium and
                               which passes through the CO2
                               scrubber The definition is instrument-
                               condition dependent

                               3 3  Nonpurgeable organic carbon is
                               defined as that which remains  after
                               removal of the purgeable  organic
                               carbon from the sample containing
                               acidified persulfate reagent and which
                               4152-1
                                                     Dec 1982

-------
 is converted to COt under the
 instrument conditions

 3.4  The system blank is the value
 obtained in 8 2 for an irradiated,
 recirculatod reagent distilled water
 sample

 4.   Sample Handling and
Preservation

 4,1  Sampling and storage of
 samples must be done in glass
 bottles Caution Do not leave any
 headspace in the sample bottle as
 this may contribute to loss  of
 purgeable organics

 4 2  Because of the possibility of
 oxidation or bacterial decomposition of
 some components of aqueous
 samples, the lapse of time between
 collection of samples and start of
 analysis should be kept to a minimum
 Also, samples should be kept cool
 (4C) and protected from sunlight and
 atmospheric oxygen

 4 3  When analysis cannot be
 performed within two hours from time
 of sampling, the sample should be
 acidified to pH 2 with H2SO<  Note
 HCI should not be used because it is
 converted to chlorine during the
 analysis This causes damage to the
 instrument

 5.   Interferences

5.1   If a sample is homogenized to
reduce the size of the paniculate
matter, the homogenizing may cause
loss of purgeable organic carbon, thus
yielding erroneously low results

6.   Apparatus

6.1  Apparatus for blending or
homogenizing samples A household
blender or similar device that will
reduce particles in the sample to less
than 0 2 mm

6,2  Apparatus for Total Organic
Carbon* The essential components for
the apparatus  used in this method
are A sparge assembly,  flow
switching valves, a pyrolysis furnace,
quartz ultraviolet reactor coil, reducing
column, flame lonization detector,
electrometer and integrator  This
method is based on the Dohrmann
Envirotech DC-54 Carbon Analyzer
Other Instruments  having similar
performance characteristics may be
used

6 3  Sampling Devices Any
apparatus that will reliably transfer
10 mL of sample to the sparger  A 50
mL glass syringe is recommended
 when analyzing samples with easily
 purgeable organics so as to minimize
 losses

 7   Reagents

 7 1  Reagent Distilled Water
 Distilled water used m preparation of
 standards and for dilution of samples
 should be ultra-pure to reduce the
 magnitude of the blank Carbon
 dioxide-free, double distilled water is
 recommended The water should be
 distilled from permanganate or be
 obtained from a system involving
 distillation and carbon treatment The
 reagent distilled water value must be
 compared to a system blank
 determined on a  recirculated distilled
 water sample The total organic
 carbon value of the reagent distilled
 water should be less than 60/ug/L
 Purgeable organic carbon  values of
 the reagent distilled water should be
 less than
 7 2  Potassium hydrogen phthalate,
 stock solution 500 mg carbon/liter
 Dissolve 1 063 g of potassium
 hydrogen phthalate (Primary Standard
 Grade) m reagent distilled water (7 1)
 and dilute to 1  liter

 7 3  Potassium hydrogen phthalate (2
 mg/L) Pipet 4 mL of potassium
 hydrogen phthalate stock solution
 (7 2) into a one liter volumetric flask
 and dilute to the mark with reagent
 distilled water (71}

 7 4  Potassium hydrogen phthalate (5
 mg/L) Pipet 1 mL of potassium
 hydrogen phthalate stock solution
 (7 2) into a 100 mL volumetric flask
 and dilute to the mark with reagent
 distilled water (7 1)

 7 5  Potassium hydrogen phthalate
 (10 mg/L) Pipet 2 mL  of potassium
 hydrogen phthalate stock solution
 (7 2) into a 100 mL volumetric flask
 and dilute to the mark with reagent
 distilled water (7 1)

 7 6 Acidified Persulfate Reagent
 Place 100 mL of reagent distilled
 water (7  1 ) m a container Add 5 g of
 potassium persulfate Add 5 g (3 mL)
 of concentrated (85%) phosphoric
 acid

 7 7 Carbonate-bicarbonate, stock
 solution,  1000 mg carbon/liter Place
 0 3500 g of sodium bicarbonate and
 0 441 8 g of sodium carbonate in a
 100 mL volumetric flask  Dissolve with
 reagent distilled water (7 1) and dilute
to the mark

7 8  Carbonate-bicarbonate, standard
solution 50 mg/L Place 5 ml of the
 carbonate-bicarbonate stock solution
 m a 100 mL volumetric flask and
 dilute to the mark with reagent
 distilled water (7 1)

 8    Procedure

 8 1   Allow at least 30 minutes
 warm-up time  Leave instrument
 console on continuously when m daily
 use, except for the ultraviolet light
 source, which should be turned off
 when not m use for more than a few
 hours

 8 2  Adjust all gas flows,
 temperatures and cycle times to
 manufacturer s specifications Perform
 the  System Cleanup and Calibration
 procedure m the manufacturer s
 specifications each day Recirculate a
 sample of irradiated distilled water
 until two consecutive readings within
 10% of each other are obtained
 Record  the last value for the system
 blank This value is a function of the
 total instrument operation and should
 not vary significantly from previous
 runs  Reasons for significant changes
 m the value should be identified

 8 3  Check the effectiveness of the
 COa scrubber by analyzing the
 carbonate-bicarbonate standard
 solution(7 8) Add 1 mL of acidified
 persulfate reagent (7 6) to 50 mL of
 the solution Transfer 10 mL of the
 solution-with-reagent to the first
 sparger and start the analysis cycle
 No response, or a very minor reading,
 should be obtained from this solution

8 4  Add 1 mL of acidified persulfate
reagent  (7 6) to 50 mL of reagent
distilled water (7 1) blank, standards
7 3, 7 4, and 7 5 and the samples

8 5  Calibrate the analyzer  as
follows

851   Run the reagent distilled water
(7 1) and 5 0 mg/L standard (7 4)
Transfer 10 mL of the solution-with-
reagent  to the first sparger and start
analyzer cycle

Ignore the meter reading for the first
cycle

Transfer a second 10 mL of the
solution-with-reagent to the first
sparger  and start the analysis cycle

Record the meter reading (see 9 1) of
the final carbon value for each of  the
reagent  distilled water (7 1) and the
standard (7 4)

If the meter reading is more than  25%
above or below the calculated value of
standard 7 4, reanalyze the standard
                                      Dec 1982
                                                                  4152-2

-------
 and set the calibration within 25%
 \Sb 4) reanalyze the system blank
 and then begin 851 again If the
 meter reading (see 9 1) is within 25%
 of the calculated value, continue to
 next step The calculated value is
 defined in 8 5 2

 852  Calculate the factor for the
 deviation of the instrument reading
 (see 9 1) for the standard (7 4) from
 the calculated value by

 standard reading -
 calculated value _ FACTOR
 calculated value

 where the calculated value is that
 value obtained by using the weight of
 potassium hydrogen phthalate and
 does not include the carbon
 contributed by the  reagent distilled
 water (7 1) with which it has been
 diluted

 853   Calculate the adjusted reading
 by
 calculated value + (ROW - (FACTOR X
 ROW)) = ADJUSTED READING
 where ROW = mean reagent distilled
 water (7 1) value

 854   Push in CALIBRATE button
 after READY light comes on and
 adjust the SPAN control to the
 ADJUSTED READING calculated m
 853

 8 6  Analyze the standards 7 3 and 7 5
 in order to check the linearity of the
 instrument at least once each day

 Transfer 10 mL of the solution-with-
 reagent to the first sparger and start
 analyzer cycle

 Ignore the meter reading for the first
 cycle

 Transfer a second 10 mL of the
 solution-with-reagent to the first
 sparger and start the analyzer cycle

 Record the meter reading (see 9 1) of
 the final carbon value for each of the
 standards 7 3 and 7 5
  The range of concentration  used for
 calibrating the instrument and
 checking the linearity of the
 instrument should be ascertained
 from a knowledge of the range of
 concentrations expected from  the
 samples Standards for lower ranges
 can be prepared by diluting standards
 72,73, and 7 4
  Transfer 10 mL of the solution-with-
reagent to the  first sparger and start
analyzer cycle

Ignore the meter reading for the first
cycle

Transfer a second 10 mL of the
solution-with-reagent to the first
sparger and  start the  analyzer cycle

Record the meter reading (see  9 1) of
the final carbon value for each of the
samples

9   Calculations

9 1  The values are read off the final
digital readout in fjg/L The  system
blank reading obtained in 8  2 must be
subtracted from all reagent  distilled
water, standard and sample readings

10   Precision and  Accuracy

101  In a single laboratory (MERL)
using raw river water  centrifuged
river wa'er drinking water  and the
effluent from a carbon column which
had concentrations of 3 11,  3 10
1 79 and 0 07 mg/L total organic
carbon respectively the standard
deviations from ten replicates were
0 13, 0 03 0 02 and +0 02
mg/L respectively

102 In a single laboratory (MERL)
using potassium hydrogen phthalate
m distilled water at concentrations of
50 and  1 0 mg/L total organic carbon,
recoveries were 80% and 91%
respectively

Bibliography
1  Proposed  Standard Method for
Purgeable and Nonpurgeable Organic
Carbon in Water (UV-promoted,
persulfate oxidation method) ASTM
Committee D-19, Task Group
19060203  (Chairman R J Joyce),
January 1978

2  Operating Instruction  Dohrmann
Envirotech 3420 Scott Boulevard
Santa Clara  California 95050

3  Takahashi, Y   Ultra Low Level
TOC  Analysis of Potable Waters
Presented at Water Quality
Technology Conference AWWA Dec
5-8  1976
8 7  Analyze the samples Transfer
10 mL of sample with  reagent to the
first sparger and start the analysis
cycle
                                     4152-3
                                                                Dec  1982

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        PETROLEUM HYDROCARBONS, TOTAL RECOVERABLE

                    Method 418.1  (Spectrophotometric, Infrared)

                                                                STORET NO. 45501

1    Scope and Application
     1 1   This  method is  for  the  measurement  of fluorocarbon-113  extractable  petroleum
           hydrocarbons from surface and saline waters, industrial and domestic wastes
     1 2   The method is applicable to measurement of light fuels, although loss of about half of any
           gasoline present during the extraction manipulations can be expected
     1 3   The method is sensitive to levels of 1 mg/1 and less, and may be extended to ambient
           monitoring
2    Summary of Method
     2 1   The sample is acidified to a low pH ( < 2) and serially extracted with fluorocarbon-113 in
           a separatory funnel  Interferences are removed  with  silica gel adsorbant Infrared
           analysis of the extract is performed by direct comparison with standards
3    Definitions
     31   As in the case of Oil and Grease, the parameter of Petroleum Hydrocarbons is defined by
           the method  The measurement may be subject to interferences and the results should be
           evaluated accordingly
     3 2   Oil and Grease is a measure of biodegradable animal greases and vegetable  oils along
           with the relative non-biodegradable mineral oils  Petroleum hydrocarbons is the measure
           of only the mineral oils Maximum information may be obtained using both methods to
           measure and characterize oil and grease of all sources
4    Sampling and Storage
     4 1   A representative sample of 1 liter volume should be collected in a glass bottle Because
           losses of grease will occur on sampling equipment, the collection of a composite sample is
           impractical  The entire sample  is consumed by this test,  no other  analyses may be
           performed using ahquots of the sample
     42   A delay between sampling and analysis of greater than  4 hours requires sample
           preservation by the addition of 5 ml HC1 (6 1) A delay of greater than 48 hours also
           requires refrigeration for sample preservation
5    Apparatus
     5 1   Separatory funnel, 2000 ml, with Teflon stopcock
     5 2   Filter paper, Whatman No 40, 11 cm
     5 3   Infrared spectrophotometer, scanning or fixed wavelength, for measurement around
           2950cm-'
     5 4   Cells, 10 mm, 50 mm,  and 100 mm pathlength, sodium chloride or infrared grade glass
     5 5   Magnetic stirrer, with Teflon coated stirring bars
6    Reagents
     6 1   Hydrochloric acid, 1 1  Mix equal volumes of cone HC1 and distilled water

Issued  1978

                                         418 1-1

-------
 6 2   Fluorocarbon-113,(1,l,2-tnchloro-l,2,2-tnfluroethane), b p 48C
 6 3   Sodium sulfate, anhydrous crystal
 6 4   Silica gel, 60-200 mesh, Davidson Grade 950 or equivalent Should contain 1-2% water
      as defined by residue test at 130C Adjust by overnight equilibration if needed
 6 5   Calibration mixtures
      65 1 Reference oil  Pipet 150 ml  n-hexadecane,  15 0 ml isooctane, and  100 ml
           chlorobenzene into a 50 ml glass stoppered bottle Maintain the integrity of the
           mixture by keeping stoppered except when withdrawing ahquots
      652 Stock standard  Pipet 1 0 ml reference oil (6 5 1) into a tared 200 ml volumetric
           flask and immediately stopper Weigh and dilute to volume with fluorocarbon-113
      653 Working standards   Pipet appropriate volumes of stock standard (6 5 2) into 100
           ml volumetric flasks according to the cell pathlength to be used Dilute to volume
           with fluorocarbon-113 Calculate concentration of standards  from  the  stock
           standard
Procedure
7 1    Mark the sample bottle at the water meniscus for later determination of sample volume
      If the sample was not acidified at time of collection, add 5  ml hydrochloric acid (6 1) to
      the sample bottle After mixing the sample,  check the pH by touching pH-sensitive paper
      to the cap to insure that the pH is 2 or lower Add more acid if necessary
7 2    Pour the sample into a separatory funnel
7 3    Add 30 ml fluorocarbon-113 (6 2) to the sample bottle and rotate the bottle to rinse the
      sides  Transfer the solvent into the separatory funnel Extract by shaking vigorously for 2
      minutes Allow the layers to separate
7 4    Filter the solvent layer through a funnel containing solvent-moistened filter paper into a
      100 ml volumetric flask
      NOTE 1 An emulsion that fails to dissipate can be broken by pouring about 1 g sodium
      sulfate (6 3) into the filter paper cone and slowly draining the emulsion through the salt
      Additional 1 g portions can be added to the cone as required
7.5    Repeat (7 3 and 7 4) twice more with 30  ml portions of fresh solvent, combining all
      solvent into the volumetric flask
7 6    Rinse the tip of the separatory funnel, filter paper, and the funnel with a total of 5-10 ml
      solvent and collect the rinsings in the flask  Dilute the extract to 100 ml If the extract is
      known  to contain greater than 100 mg of  non-hydrocarbon organic material, pipet an
      appropriate portion of the sample to a 100 ml volumetric and dilute to volume
7 7    Discard about 5-10 ml solution from the volumetric flask  Add 3 g silica gel (6 4) and a
      stirring bar, stopper the volumetric flask, and stir the solution for a minimum of 5 mm on
      a magnetic stirrer
                                     418 1-2

-------
 7 8   Select appropriate working standards and cell pathlength according to the following
      table of approximate working ranges

                  Pathle"gth                                      Range

                                                                    mg

      Calibrate the instrument for the appropriate cells using a series of working standards
      (6 5 3)  It is not necessary to add silica gel to the standards  Determine absorbance
      directly for each solution at the absorbance maximum at about 2930 cm"1  Prepare a
      calibration plot of absorbance vs  mg petroleum hydrocarbons per 100 ml solution
7 9   After the silica gel has settled in the sample extract, fill a clean cell with solution and
      determine the absorbance of the  extract  If the absorbance exceeds 0 8 prepare an
      appropriate dilution
      NOTE 2:  The possibility that the absorptive capacity of the silica gel has been exceeded
      can be tested at this point by adding another 3 0 g silica gel to the extract and repeating
      the treatment and determination
7 10  Determine the concentration of petroleum hydrocarbons in the extract by comparing the
      response against the calibration plot
Calculations
8 1   Calculate the petroleum hydrocarbons in the sample using the formula


     mg/1 Petroleum Hydrocarbons =  R * P
     where

     R = mg of Petroleum Hydrocarbons as determined from the calibration plot (7 10)
     D = extract dilution factor, if used
     V = volume of sample, in liters
 Precision and Accuracy
 9 1   Precision and accuracy data are not available at this ti
                                                      me
                                  418 1-3

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                      PHENOLICS,  TOTAL  RECOVERABLE

       Method 420.1 (Spectrophotometric, Manual  4-AAP with Distillation)

                                                                 STORET NO. 32730

      Scope and Application
      1 1  This method is applicable to the analysis of drinking, surface and saline waters, domestic
           and industrial wastes
      1 2  The method is capable of measuring phenolic materials at the 5 ug/1 level when the
           colored end product is extracted and concentrated in a solvent phase using phenol as a
           standard
      1 3  The method is capable of measuring phenolic materials that contain more than 50 ug/1
           in the aqueous phase (without solvent extraction) using phenol as a standard
      14  It is not possible to use this method to differentiate between different kinds of phenols
      Summary of Method
      2 1   Phenolic  materials react  with 4-aminoantipynne in the  presence  of  potassium
           ferncyanide at a pH of 10 to form a stable reddish-brown colored antipynne dye The
           amount of color produced is a function of the concentration of phenolic material
      Comments
      3 1   For most samples a preliminary distillation is required to remove interfering materials
      3 2   Color response of phenolic materials with 4-ammo antipynne is not  the same for all
           compounds Because phenolic type wastes usually contain a variety of phenols, it is not
           possible to duplicate a  mixture of phenols to be used as a standard For this reason phenol
           has been selected as a standard and any color produced by the reaction of other phenolic
           compounds is reported as phenol This value will represent the minimum concentration
           of phenolic compounds present in the sample
      Sample Handling and Preservation
      4  1   Biological degradation is inhibited by the addition  of 1 g/1 of copper sulfate to the
           sample and acidification to a pH of less than 4 with phosphoric acid The sample should
           be kept at 4C and analyzed within 24 hours after collection
      Interference
      5  1   Interferences from sulfur compounds are eliminated by acidifying the sample to a pH of
           less than 4 with H3PO4 and aerating briefly by stirring and adding CuSO4
      5 2   Oxidizing agents such  as chlorine, detected by the liberation  of iodine upon acidification
           in the presence of potassium iodide, are removed immediately after sampling by the
           addition of an excess of ferrous ammonium sulfate  (7 10) If chlorine is not removed,
           the phenolic compounds may be partially oxidized and the results may be low
Approved for NPDES
Issued 1971
Editorial revision 1978

                                        420 1-1

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 6.    Apparatus
      6 1   Distillation apparatus, all glass consisting of a 1 liter pyrex distilling apparatus with
           Graham condenser
      6 2   pH meter
      6 3   Spectrophotometer, for use at 460 or 510 nm
      6 4   Funnels
      6 5   Filter paper
      6 6   Membrane filters
      6 7   Separatory funnels, 500 or 1,000 ml
      6 8   Nessler tubes, short or long form
7     Reagents
      7 1   Phosphoric acid solution, 1 + 9 Dilute 10 ml of 85% H3PO4 to 100 ml with distilled
           water
      7 2   Copper sulfate solution Dissolve  100 g CuSO45H2O in distilled water and dilute to 1
           liter
      7.3   Buffer solution Dissolve 16 9 g NH4C1 in 143 ml cone NH4OH and dilute to 250 ml
           with distilled water Two ml should adjust 100 ml of distillate to pH 10
      7 4   Ammoantipynne solution Dissolve 2 g of 4AAP in distilled water and dilute to 100 ml
      7 5   Potassium ferncyanide solution Dissolve 8 g of K3Fe(CN)6 m distilled water and dilute
           to 100 ml
      7.6   Stock phenol solution Dissolve 1 0 g phenol in freshly boiled and cooled distilled water
           and dilute to 1 liter 1 ml = 1 mg phenol
      7 7   Working solution A  Dilute 10 ml stock phenol solution to 1 liter with distilled water
           1 ml =  10 ug phenol
      7 8   Working solution B  Dilute 100 ml of working solution A to 1000 ml with distilled water
           1 ml  = 1 ug phenol
      7 9   Chloroform
      7.10 Ferrous ammonium sulfate Dissolve 1 1 g ferrous ammonium sulfate in 500 ml distilled
          water containing 1 ml cone HaSO4 and dilute to 1 liter with freshly  boiled and cooled
          distilled water
8     Procedure
      8  1   Distillation
           811  Measure 500 ml sample into a beaker Lower the pH to approximately 4 with 1+9
                H3PO4 (7 1), add 5 ml  CuSO4  solution (7 2)  and transfer to the  distillation
                apparatus Omit adding H2PO4 and CuSO4 if sample was preserved as described in
                41
           812 Distill 450 ml of sample, stop the distillation, and when boiling ceases add 50 ml of
                warm distilled water to the flask and resume distillation until 500 ml have been
                collected
           813  If the distillate is turbid, filter through a prewashed membrane filter
      8 2   Direct photometric method
           821  Using working solution  A  (7 7), prepare the  following standards in 100 ml
                volumetric flasks
                                          420 1-2

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                 ml of working solution  A           Cone ug/1
                           ET                        o~0
                           05                       500
                           10                      1000
                           20                      2000
                           50                      5000
                           80                      8000
                          10 0                     1000 0

      8 2 2 To 100 ml of distillate or an aliquot diluted to 100 ml and/or standards, add 2 ml of
           buffer solution (7 3) and mix The pH of the sample and standards should be
           10 02
      823 Add 2 0 ml ammoantipyrme solution (7 4) and mix
      824 Add 2 0 ml potassium ferncyanide solution (7 5) and mix
      825 After 15 minutes read absorbance at 510 nm
8 3   Chloroform extraction method
      8 3 1 Using working solution B (7 8), prepare the following standards Standards may be
           prepared by pipetting  the required volumes  into the separatory funnels and
           diluting to 500 ml with distilled water


                ml  of working solution B           Cone ug/1
                          00                        00
                          30                        60
                          50                       100
                         10 0                       20 0
                         20 0                       40 0
                         25 0                       50 0

      832 Place 500 ml of distillate or an aliquot diluted to 500 ml in a separatory funnel The
           sample should not contain more than 25 ug phenol
      8 3 3 To sample and standards add 10 ml of buffer solution (7 3) and mix The pH
           should be 10 02
      834 Add 3 0 ml ammoantipyrme solution (7 4) and mix
      835 Add 3 0 ml potassium ferncyanide solution (7 5) and mix
      836 After three minutes, extract with 25 ml of chloroform (7 9) Shake the separatory
           funnel at least 10 times,  let CHC13 settle, shake again 10 times and let chloroform
           settle again  Vent chloroform fumes into hood
      837 Filter chloroform extracts through filter paper Do not add more chloroform
      Carryout filtration in  a hood Dispose of chloroform  in  environmentally
      acceptable manner
      838 Read the absorbance of the samples and standards against the blank at 460 nm
Calculation
9 1   Prepare a standard curve by plotting the absorbance value of standards versus the
      corresponding phenol concentrations
9 2   Obtain concentration value of sample directly from standard curve.
                                    420 1-3

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10   Precision and Accuracy
     10 1  Using the extraction procedure for concentration of color, six laboratories analyzed
           samples  at  concentrations of 9 6,  48 3, and  93 5  ug/1  Standard deviations were
           0 99, 3 1 and 4 2 ug/1, respectively
     10 2  Using the  direct  photometric  procedure, six laboratories analyzed  samples  at
           concentrations of 4 7, 48 2 and 97 0 mg/1 Standard deviations were 0 18,  0 48 and
           1 58 mg/1, respectively

                                      Bibliography

1    Annual Book of ASTM Standards, Part 31, "Water", Standard D1783-70, p553 (1976)
2.    Standard Methods for the Examination of Water and Wastewater, 14th Edition, p574-581,
     Method 510 through 5 IOC, (1975)
                                         420 1-4

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                    PHENOLICS, TOTAL RECOVERABLE

        Method 420.2  (Colorimetric,  Automated 4-AAP with  Distillation)

                                                               STORET  NO.  32730

1    Scope and Application
     1 1  This method is applicable to the analysis of drinking, surface and saline waters, domestic
          and industrial wastes
     1 2  The method is capable of measuring phenolic materials from 2 to 500 ug/1 m the
          aqueous phase using phenol as a standard  The working ranges are 2 to 200 ug/1 and 10
          to 500 ug/1
2    Summary of Method
     2 1  This automated method is based on the distillation of phenol and subsequent reaction of
          the distillate with alkaline ferncyamde and 4-ammoantipynne to form a red complex
          which is measured at 505 or 520 nm The same manifold is used with the AAI or AAII
3    Sample Handling and Preservation
     3 1  Biological degradation is  inhibited by the addition of 1 g/1 of copper sulfate to the
          sample and acidification to a pH of less than 4 with phosphoric acid The sample should
          be kept at 4C and analyzed within 24 hours after collection
4    Interference
     4 1  Interferences from sulfur compounds are eliminated by acidifying the sample to a pH of
          less than 4 0 with H3PO4 and aerating briefly by stirring and adding CuSO4
     4 2  Oxidizing agents such as chlorine, detected by the liberation of iodine upon acidification
          in the presence of potassium iodide, are  removed immediately after sampling by the
          addition of an excess of ferrous ammonium sulfate (6 5) If chlorine is not removed, the
          phenolic compounds may be partially oxidized and the results may be low
     4 3  Background contamination from plastic tubing and sample containers is eliminated by
          filling the wash receptacle by siphon (using Kel-F tubing) and using glass tubes for the
          samples and standards
5    Apparatus
     5 1  Techmcon AutoAnalyzer (I or II)
          511  Sampler equipped with continuous mixer
          5 1 2  Manifold
          513  Proportioning pump II or III
          514  Heating bath with distillation coil
          5 1 5  Distillation head
          5 1 6  Colorimeter equipped with a 50 mm flow cell and 505 or 520 nm filter
          5 1 7  Recorder
6    Reagents
     6 1  Distillation reagent Add  100 mi of cone  phosphoric acid  (85% H3PO4) to 800 ml of
          distilled water, cool and dilute to 1 liter

Issued  1974

                                        420 2-1

-------
 6 2   Buffered potassium ferncyamde Dissolve 2 0 g potassium ferncyamde, 3 1 g bone acid
      and 3 75 g potassium chloride m 800 ml of distilled water Adjust to pH of 10 3 with 1 N
      sodium hydroxide (6 3) and dilute to 1 liter Add 0 5 ml of Bnj-35 Prepare fresh weekly
 6 3   Sodium hydroxide (IN) Dissolve 40 g NaOH in 500 ml of distilled water, cool and dilute
      to 1 liter
 6 4   4-Ammoantipynne Dissolve 0 65 g of 4-aminoantipyrme in 800 ml of distilled water and
      dilute to 1 liter Prepare fresh each day
 6 5   Ferrous ammonium sulfate Dissolve 1 1 g ferrous ammonium sulfate in 500 ml distilled
      water containing 1 ml H2SO4 and dilute to 1 liter with freshly boiled and cooled distilled
      water
 6 6   Stock phenol  Dissolve 1 00 g phenol m 500 ml of distilled water and dilute to 1000 ml
      Add 1 g CuSO4 and 0 5 ml cone H3PO4 as preservative 1 0 ml = 10 mg phenol
 6 7   Standard phenol solution A Dilute 10 0 ml of stock phenol solution (6 6) to 1000 ml
      10  ml  =  0 01 mg phenol
 6 8   Standard phenol solution B Dilute 100 0 ml of standard phenol solution A (6 7) to 1000
      ml with distilled water  1 0 ml = 0 001 mg phenol
 6 9   Standard solution C  Dilute 100 0 ml of standard phenol solution B (6 8) to 1000 ml with
      distilled water  1 0 ml = 0 0001 mg phenol
 610  Using standard solution A, B or C prepare the following standards in 100 ml volumetric
      flasks Each standard should be preserved by adding 0  1  g CuSO4 and 2 drops of cone
      H3PO4tolOOOml

           ml of Standard Solution                              Cone  ug/1
                 Solution C
                   10                                            10
                   20                                            20
                   30                                            30
                   50                                            50

                 Solution B

                   10                                           100
                   20                                           200
                   50                                           500
                  100                                          1000

                 Solution A
                    2                                           200
                    3                                           300
                    5                                           500

Procedure
7 1  Set up the manifold as shown in Figures 1 or 2
7 2  Fill the wash receptacle by siphon Use Kel-F tubing with a fast flow (1 liter/hr)
7 3  Allow colorimeter and recorder to warm up for 30 minutes Run a baseline with all
     reagents, feeding distilled water through the sample line Use polyethylene tubing for
                                    420 2-2

-------
          sample line When new tubing is used, about 2 hours may be required to obtain a stable
          baseline This two. hour time period may be necessary to remove the residual phenol from
          the tubing
     7 4  Place appropriate phenol standards in sampler in  order of decreasing concentration
          Complete loading pf sampler tray with unknown samples, using glass tubes
          NOTE 1: If samples have not been preserved as instructed m (3 1), add 0 1 g CuSO4 and
          2 drops of cone H3PO4 to 100 ml of sample
     7 5  Switch sample line from distilled water to sampler and begin analyses
8    Calculation
     8 1  Prepare standard curve  by plotting peak heights of  standards against concentration
          values Compute concentration of samples by  comparing sample peak heights with
          standards
9    Precision and Accuracy
     91  In a single laboratory (EMSL), using sewage samples at concentrations of 3 8, 15,43 and
          89 ug/1, the standard deviations were 0,5,  0 6, 0 6 and  1,0 ug/1, respectively At
          concentrations of 73,  146, 299 and 447 ug/1, the  standard deviations were 10,
          18,  42 and 5 3 ug/1, respectively
     92  In a single laboratory  (EMSL), using sewage samples at concentrations of 5 3 and 82
          ug/1, the recoveries were 78% and 98% At concentrations of 168 and 489 ug/1, the
          recoveries were 97% and 98%, respectively

                                      Bibliography

1    Techmcon Auto Analyzer II Methodology, Industrial Method No  127-71W, A All
2    Standard Methods for the Examination of Water and  Wastewater,  14th Edition,  p 574,
     Method 510 (1975)
3    Gales, M E and Booth, R,L , "Automated 4 AAP Phenolic Method", AWWA 68, 540 (1976)
                                         420 2-3

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                                                420 2-5

-------
                     PHENOLICS, TOTAL RECOVERABLE

           Method  420.3  (Spectrophotometric,  MBTH with  Distillation)

                                                                 STORET NO. 32730

 1     Scope and Application
      1 1   This method is applicable to the analysis of drinking, surface and saline waters, domestic
           and industrial wastes
      1 2   The method is capable of measuring phenolic materials at the 2 ug/1 level when the
           colored end product is extracted and concentrated in a solvent phase using phenol as a
           standard
      1 3   The method is capable of measuring phenolic materials that contain from 50 to 1000
           ug/1 in the aqueous phase (without solvent extraction) using phenol as a standard
      14   It is not possible to use this method to differentiate between different kinds of phenols
 2     Summary of Method
      2 1   This method is based on the coupling of phenol with MBTH in an acid medium using
           cenc ammonium sulfate as an oxidant The coupling takes place in the p-position, if this
           position is occupied, the MBTH reagent will react at a  free o-position The  colors
           obtained have maximum absorbance from 460-595 nm For phenol and most phenolic
           mixtures the absorbance is 520 and 490 nm
 3     Comments
      3 1   For most samples a preliminary distillation is required to remove interfering materials
      3 2   Color response of  phenolic materials with MBTH is not the same for all compounds
           Because phenolic type wastes usually contain a variety of phenols, it is not possible to
           duplicate a mixture of phenols to be used as a standard For this reason phenol has been
           selected as  a  standard and  any color produced by the  reaction  of other  phenolic
           compounds is  reported as phenol  This value will represent the minimum concentration
           of phenolic compounds present in the sample
4     Sample Handling and Preservation
      4 1   Biological degradation is inhibited by the addition of 1 g/1 of copper sulfate  to the
           sample and acidification to a  pH of less than 4 with sulfunc acid The sample should be
           kept at 4C and analyzed within 24 hours after collection
5     Interference
      5 1   Interferences from  sulfur compounds are eliminated by acidifying the sample to a pH of
           less than 4 0 with H2SO4 and aerating briefly by stirring and adding CuSO4
      5 2   Oxidizing agents such as chlorine, detected by the liberation of iodine upon acidification
           in the presence of potassium iodide, are removed immediately after sampling by the
           addition of an  excess of ferrous ammonium sulfate (6 5) If chlorine is not removed, the
           phenolic compounds may be partially oxidized and the results may be low
      5 3   Phosphate causes a precipitate to form, therefore, phosphoric acid should not be used for
           preservation All glassware should be phosphate free

Issued 1978

                                         420 3-1

-------
     5 4  High concentrations of aldehydes may be an interference
6,   Apparatus
     6 1   Distillation apparatus  All glass consisting of a 1 liter pyrex distilling apparatus with
           Graham condenser
     6 2   pH meter
     6 3   Spectrophotometer
     6 4   Funnels
     6 5   Filter paper
     6 6   Membrane filters
     6 7   Separatory funnels
7.   Reagents
     7 1   Copper sulfate solution Dissolve 100 g CuSO45 H2O in distilled water and dilute to 1
           liter
     7 2   Sulfunc acid, 1 N Add 28 ml of cone H2SO4 to 900 ml of distilled water, mix and dilute
           to 1 liter
     7 3   MBTH solution, 0 05%  Dissolve 0 1 g  of 3-methyl-2-benzothiazolmone hydrazone
           hydrochlonde in 200 ml of distilled water
     7 4   Cenc ammonium sulfate solution Add 2 0 g of Ce(SO4)22(NH4)2SO42H2O and 2 0 ml
           of cone H2SO4 to 150 ml of distilled water  After the solid has dissolved dilute to 200 ml
           with distilled water
     7 5   Buffer solution  Dissolve in the following  order, 8 g of sodium hydroxide, 2 g EDTA
           (disodmm salt) and 8 g boric acid in 200  ml of distilled water Dilute to 250  ml with
           distilled water
     7.6   Working buffer solution Make a working solution by mixing an appropriate volume of
           buffer solution (7 5) with an equal volume of ethanol
     7 7   Chloroform
     7 8   Stock phenol Dissolve 1 00 g phenol in 500 ml of distilled water and dilute to  1000 ml
           Add 1 g CuSO4 and 0 5 ml cone  H2SO4 as preservative 1 0 ml = 1 0 mg phenol
     7.9   Standard phenol solution A Dilute 10 0 ml of stock phenol solution (7 8) to 1000 ml 1 0
           ml = 0 01 mg phenol
     7.10  Standard phenol solution B Dilute 100 0 ml of standard phenol solution A (7 9) to 1000
           ml with distilled water  1 0 ml = 0 001 mg phenol
8    Procedure
     8 1   Distillation
           8 1 1 To 500 ml of sample add 5 ml of copper sulfate solution (7 1) and adjust the pH to
                approximately 4 with 1 N sulfunc acid solution (7 2)
           8.1 2 Distill over 450 ml of sample,  add 50 ml of warm distilled water to flask, and
                resume distillation until 500 ml has been collected
           813  If the distillate is turbid, filter through a prewashed membrane filter
     8 2  Concentration above 50 ug/1
           821  To 100 ml of distillate or an aliquot diluted to 100 ml, add 4 ml of MBTH solution
                (73)
           822 After 5 minutes, add 2 5 ml of cenc amihomum sulfate solution (7 4)
                                        420 3-2

-------
           823 Wait another 5 minutes and add 7 ml of working buffer solution (7 6)
           824 After 15 minutes, read the absorbance at 520 nm against a reagent blank The color
                is stable for 4 hours
     8 3   Concentration below 50 ug/1
           8 3 1 To 500 ml of distillate in a separately funnel, add 4 ml of MBTH solution (7 3)
           832 After 5 minutes, add 2 5 ml of eerie ammonia sulfate solution (7 4)
           833 After an additional 5 minutes, add 7 ml of working buffer solution (7 6)
           834 After 15 minutes, add 25 ml of chloroform  Shake the separatory funnel at least 20
                times  Allow the layer to separate, and pass the chloroform layer through filter
                paper
           835 Read the absorbance at 490 nm against a reagent blank
9    Calculation
     9 1   Prepare a standard curve by plotting absorbance against concentration values
     9 2   Obtain concentration value of sample directly from prepared standard curve
10   Precision and Accuracy
     101  Precision and accuracy data are not available at this time

                                      Bibliography

1    Fnestad, H O , Ott, E E, and Gunther, F A , "Automated Colonmetnc Micro Determination
     of Phenol  by Oxidative Coupling with 3-Methyl-2-benzothiazolmone Hydrazone", Techmcon
     International Congress (1969)
2    Gales, M  E, "An Evaluation of the 3-Methyl-2 benzothiazohnone Hydrazone Method for the
     Determination of Phenols in Water and Wastewater", Analyst, 100, No 1197, 841 (1975)
                                         420 3-3

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           METHYLENE BLUE ACTIVE SUBSTANCES (MBAS)

                            Method 425.1 (Colorimetric)

                                                               STORET NO.  38260

     Scope and Application
     1 1   This method  is applicable to the measurement of methylene blue active substances
          (MBAS) in drinking waters,  surface waters,  domestic and industrial wastes It is not
          applicable to measurement of surfactant-type materials in salme waters
     12   It is not possible to differentiate between linear alkyl sulfonate (LAS) and alkyl benzene
          sulfonate (ABS) or other isomers of these types of compounds  However, LAS has
          essentially replaced ABS on the surfactant market so that measurable surfactant
          materials will probably be LAS type materials
     1 3   The method is applicable over the range of 0 025 to 100 mg/1 LAS
     Summary of Method
     2 1   The dye, methylene blue, m  aqueous solution reacts with amomc-type surface active
          materials to form  a blue colored salt The salt is extractable with chloroform and the
          intensity of color produced is proportional to the concentration of MBAS
     Comments
     3 1   Materials other than man-made surface active agents which react with methylene blue
          are organically bound sulfates, sulfonates, carboxylates, phosphates, phenols, cyanates,
          thiocyanates and  some inorganic ions  such  as  nitrates and chlorides However, the
          occurrence of these materials at interference levels is relatively  rare and with the
          exception of chlorides may generally be disregarded
     3 2   Chlorides  at concentration of about 1000 mg/1 show a positive interference  but the
          degree of interference has not been quantified  For this reason  the method is not
          applicable to brine samples
     3 3   Naturally occurring organic matenals that  react with methylene blue are relatively
          insignificant Except under highly unusual circumstances, measurements of MBAS in
          finished waters, surface waters and  domestic sewages may be assumed to be accurate
          measurements of man-made surface active agents
     Precision and Accuracy
     41   On a sample of filtered river water, spiked with 2 94 mg LAS/liter, 110 analysts obtained
          a mean of 2 98 mg/1 with a standard deviation of  0 272
     4 2