Federal Water Pollution Control Administration
         Division of Water Quality Research
         Analytical Quality Control Laboratory
                 Cincinnati, Ohio
FWPCA  METHODS  FOR CHEMICAL  ANALYSIS

                      OF

            WATER  AND  WASTES
                 NOVEMBER, 1969
          U.S. DEPARTMENT OF THE INTERIOR

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      FWPCA METHODS FOR CHEMICAL ANALYSIS




              OF WATER AND WASTES
                NOVEMBER 1969
        U.S.  DEPARTMENT OF THE INTERIOR




FEDERAL WATER POLLUTION CONTROL ADMINISTRATION




      DIVISION OF WATER QUALITY RESEARCH




     ANALYTICAL QUALITY CONTROL LABORATORY




                 1014 BROADWAY




                CINCINNATI, OHIO

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                              PREFACE



This manual describes the analytical procedures selected for use

in FWPCA laboratories for the chemical analysis of water and waste

samples.  The methods were chosen by a committee of senior chemists

from within the Administration, using Standard Methods for the

Examination of Water and Wastewater, 12th Edition (1965) and ASTM

Standards, Part 23, Water; Atmospheric Analysis (1968) as basic

references.  Where acceptable methods were not available from these

sources, detailed descriptions of suitable procedures are included

in this manual.



In order to provide reliable water quality and waste constituent

data for use by FWPCA, these procedures will be used in all

Administration laboratories except under very unusual circumstances.

Other agencies and individuals are encouraged to use these methods,

in the interest of uniformity throughout the water pollution control

effort.
                              5avid G. Stephan
                           Assistant Commissioner
                           Research  Development
                              Allan Hirsch
                     Acting Assistant Commissioner
                         Office of Operations

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                         INTRODUCTION








This 1969 edition of "FWPCA Methods for Chemical Analysis of Water and




Wastes" describes chemical analytical procedures to be used in FWPCA




laboratories.   The methods were selected by a team of senior scientists




within FWPCA based on the following criteria:




(1) The method should measure the desired constituent with precision




    and accuracy sufficient to meet the data needs of FWPCA, in the




    presence of the interferences normally encountered in polluted




    waters.




(2) The procedures should utilize the equipment and skills normally




    available in the typical water pollution control laboratory.




(3) The selected methods are in use in many laboratories or have been




    sufficiently tested to establish their validity.




(4) The methods should be sufficiently rapid to permit routine use for




    the examination of a large number of samples.




Except where noted under "Scope and Application" for each constituent,




the methods are useful for the measurement of the indicated constituent




in both water and wastewaters and in both saline and fresh water samples,




Table I lists the parameter to be measured, the basis of the analytical




method, the reference volume which contains a detailed description of




the procedure, and the STORET number to be used in recording the final




result.  The reader should note that most of the detailed analytical




procedures found in this manual will ultimately appear in Standard




Methods for the Examination of Water and Wastewater, 13th Edition',




and/or ASTM Standards, Part 23.  A majority of the procedures have been
                                   111

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accepted for future publication and adoption by these organizations or




are under consideration by the appropriate subcommittees.








The 1969 edition contains a number of procedures not included in pre-




vious publications of FWPCA methods.  In particular, procedures are




included for the use of the AutoAnalyzer for the determination of alka-




linity, chloride, fluoride, hardness, Kjeldahl nitrogen, ammonia nitrogen,




nitrate nitrogen, phosphorus, and sulfate.  In certain cases two pro-




cedures are offered, since definitive data are not presently available




to indicate a choice.  Detailed instructions are also given for the




measurement of metals by atomic absorption spectroscopy.  The dissolved




oxygen probe and the fluoride specific ion electrode are included as




alternative methods.








Certain changes in recommended FWPCA methods have been made, notably




(a) the use of the pyridine pyrazalone method for the determination of




cyanide replacing the benzidine pyridine method; (b) the use of glass




fiber filters instead of membrane filters in the determination of sus-




pended solids; and (c) a drying temperature of 180C in place of the




previously recommended 105C for dissolved solids measurement.








Specific instructions for the handling and preservation of samples




cannot be given because of the wide variability in types of samples




and local sampling situations.  However, certain general principles




should be followed.  Wherever possible, the sampling program should




be designed to provide for the shortest possible interval between




sample collection and analysis.  Positive steps should be taken to
                                   IV

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maintain both the concentration and the physical state of the consti-




tuents to be measured.  Where both total and dissolved concentrations




are to be determined, the dissolved concentration is the amount present




after filtration through a 0.45 micron membrane filter.   When the dis-




solved concentration is to be determined, filtration should be carried




out as soon as possible after collection of the sample,  preferably in




the field.  Where field filtration is not practical, the sample should




be filtered as soon as it is received in the laboratory.








In situations where the interval between sample collection and analysis




is long enough to produce significant changes in either the concen-




tration or the physical state of the constituent to be measured, the




preservatives listed in Table II are recommended.








Although every effort has been made to select methods which are appli-




cable to the widest range of sample types, circumstances may require




that alternative procedures be used in place of the methods recommended




herein.  In these situations, the analyst is urged to define the nature




of the interference with the FWPCA method and bring this information to




the attention of the Analytical Quality Control Laboratory through the




appropriate Regional AQC Coordinator.  The analyst should also suggest




alternative procedures which have been found to be superior for this




kind of sample condition.  In this manner, any weaknesses in the selected




methods and the preferable alternatives can be called to the attention




of all laboratories utilizing the FWPCA methods.

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The methods described herein  were  selected with the assistance of the
following Regional Analytical Quality Control Coordinators:
Richard T. Dewling
AQC Coordinator
Hudson-Delaware Basins Office
Northeast Region, FWPCA
Edison, New Jersey 08817

Kenneth R. Tinsley
AQC Coordinator
Middle Atlantic Region, FWPCA
918 Emmet Street
Charlottesville, Virginia 22901

William T. Donaldson
AQC Coordinator
Southeast Water Laboratory
Southeast Region, FWPCA
College Station Road
Athens, Georgia 30601

Jacob D. Dumelle
ATTN:  LeRoy E. Scarce
AQC Coordinator
Great Lakes Region, FWPCA
1819 West Pershing Road
Chicago, Illinois 60605
Theodore 0.  Meiggs
AQC Coordinator
Missouri Basin Region Laboratory
Missouri Basin Region, FWPCA
7300 Rochester Road, Box 4963
Kansas City, Missouri 64120

Robert E. Crowe
AQC Coordinator
Kerr Water Research Center
South Central Region, FWPCA
P. 0. Box 1198
Ada, Oklahoma 74820

Daniel F. Krawczyk
AQC Coordinator
Pacific Northwest Water Laboratory
Northwest Region, FWPCA
200 South 35th Street
Corvallis, Oregon 97330

John C. Merrell, Jr.
AQC Coordinator
Southwest Region, FWPCA
Phelan Bldg., 760 Market Street
San Francisco, California 94102
                  Robert  L.  Booth
                  AQC  Coordinator
                  Analytical Quality  Control Laboratory
                  Ohio Basin Region,  FWPCA
                  1014 Broadway
                  Cincinnati,  Ohio  45202
                                    VI

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                                         FWPCA METHODS  FOR CHEMICAL ANALYSIS
                                                OF WATER AND WASTES
                                                     JULY, 1969
                                                       TABLE I
Parameter

Acidity, Total (mg/1 as CaCO_)
Alkalinity, Total (mg/1 as CaCO )
Aluminum, Total (yg/1
, Dissolved (yg/1)
Arsenic, Inorganic (yg/1)
Biochemical Oxygen Demand,
5 day mg/1)
Cadmium, Total (yg/1)
, Dissolved (yg/1)
Calcium, Total (mg/1)
Chemical Oxygen Demand (mg/1)
Low Level (mg/1)
Saline Waters (mg/1)
Storet
Number

00435
00410
01105
01000
00310
01025
00915
00340
00335
00340
Method

Electrometric titration - pH 8.3
Electrometric titration - pH 4.5
Technicon - Methyl Orange
Atomic Absorption
Filtration through 0.45y MF
Silver diethyldithiocarbomate
Winkler-azide or DO analyzer
Atomic Absorption
Filtration through 0.45y MF
Atomic Absorption
Dichromate reflux - 0.25N
- 0.025N
- Chloride, correction
Referenc
Std. Meth.
12th Ed.
(1965)

This Ma
This Ma
This Ma
p. 56-57
This Ma
This Ma
This Ma
p. 510-514
This Ma
This Ma
es to be Used
ASTM Stds.
Part 23
(1968)

lual
p. 155
lual
mal

lual
lual
lual
p. 244
lual
mal
uses

*
*

*

*
*
*
:(See USGS Reference,  last page  of  index)

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                                        FWPCA METHODS FOR CHEMICAL ANALYSIS
                                               OF WATER AND WASTES
Parameter

Chloride (mg/1)
Chlorine Demand,
15 min. (mg/1)
1 hr. (mg/1)
2 hr. (mg/1)
24 hr. (mg/1)
Chlorine Residual (mg/1)
Chromium, Total (yg/1)
, Dissolved (pg/1)
Color, Units
Copper, Total (yg/1)
, Dissolved (yg/1)
Cyanide (mg/1)
Storet
Number Method

00940
00365
00370
00375
00380
50060
01030
00080
01040
00720
Mercuric nitrate titration
Technicon - Ferricyanide
Amperometric titration
Amperometric titration
Atomic Absorption
Filtration through 0.45y MF
Platinum-cobalt visual
Atomic Absorption
Filtration through 0.45y MF
Silver nitrate titration or pyridine-
pyrazalone
Referei
Std. Meth.
12th Ed.
(1965)

p. 87-90
This M;
p. 381-383
p. 378
This M;
This M;
This M;
This M;
ices to be Used
ASTM Stds.
Part 23
(1968)

p. 24
nual


nual
nual
nual
nual
uses

*


*
*
*
*
:(See USGS Reference, last page of index)

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                                               FWPCA METHODS FOR CHEMICAL ANALYSIS
                                                      OF WATER AND WASTES
CO




Parameter
[ f
I References to be Used

Std* Meth.
Storet i 12th Ed.
Number Method (1965)
ASTM Stds.


i
Dissolved Oxygen
Fluoride (mg/1)
(mg/1) 00300 ; Winkler-azide or DO analyzer i This
00950 ; SPADNS, with distillation i p. 144-146
1 Technicon - complexone This
Probe i This
Hardness, 1 ;
Total, (mg/1 as CaCO ) 00900 j EDTA titration p. 147-152
j Technicon - E.B.T. This


Iron, Total (yg/1)
, Dissolved (yg/1) 01046
Lead, Total (yg/1)
, Dissolved (yg/1)
Magnesium, Total
(mg/1)
Manganese, Total (yg/1)
, Dissolved (yg/1)
01049
00925
01055
Calculation - Ca + Mg by atomic absorption j This
Atomic Absorption '.
Filtration through 0.45y MF i This
Atomic Absorption
Filtration through 0.45y MF This
Atomic Absorption This
Atomic Absorption
Filtration through 0.45 MF This
M
Part 23 '
(1968)


uses

mual
1
p. 212-217 [
Manual ;
Manual
Manual
Manual
j
Manual
M
M
M
mual
mual
mual
*

*

*
*
*
*
      r(See USGS Reference,  last page of index)

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                                          FWPCA  METHODS  FOR CHEMICAL ANALYSIS
                                                 OF  WATER AND WASTES
        Parameter
                                                                                                References to be Used
Storet
Number
                 Method
jStd. Meth.   ASTM Stds..
j 12th Ed.    ;  Part 23
I   (1965)     j  (1968)    USGS
MBAS (mg/1)
38260    Methylene Blue
                                            p.  297-299
Nitrogen, Ammonia  (mg/1)
00610    Distillation (pH 9.5) - Nesslerization
         Technicon - sodium phenolate
                                                  This Manual
                                                  This Manual
                                                         i
Nitrogen, Kjeldahl, Total  (mg/1)
00625    Digestion - distillation
         Technicon - digestion + phenolate
                                                  This Manual
                                                  This M4nual
Nitrogen, Nitrate  (mg/1)
00620   I Brucine sulfate
        j Technicon - hydrazine reduction
                                                  This Manual
                                                  This Manual
Nitrogen, Nitrate - Nitrite  (mg/1)
         Technicon - cadmium reduction
                                                  This M
             nual
Nitrogen, Nitrite  (mg/1)
00615
Diazotization
Technicon - diazotization
      This Mdnual
      This M; nual
Nitrogen, Organic + Ammonia (mg/1)
00635
Technicon - digestion + phenolate
      This Mi
nual
Oil  Grease (mg/1)
00550
Hexane soxhlet extraction
      This M;
nual
 '(See USGS Reference, last page of index)

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                                         FWPCA METHODS  FOR  CHEMICAL ANALYSIS
                                                OF WATER AND WASTES
Parameter

Organic Carbon, Total (mg/1)
, Dissolved (mg/1)
pH (units)
Phenolics (mg/1)
Phosphorus , (mg/ 1 )
Hydrolyzable (mg/1)
Orthophosphate (mg/1)
Phosphorus, Dissolved
Potassium, Total (mg/1)
, Dissolved (mg/1)
Storet
Number

00680
00681
00400
32730
00665
70507
00666
00935
Method

Dow Beckman (MOD #915) or Carbonaceous
Analyzer
Filtration through 0.45y MF
Electrometric
4-aminoantipyrine
Persulfate - digestion + single reagent
Technicon - manual digestion + automated
single reagent or stannous
chloride
Sulfuric acid digestion + single reagent
Technicon - manual digestion + automated
single reagent or stannous
Direct single reagent chloride
Technicon - single reagent or stannous
chloride
Filtration through 0.45p MF
Atomic Absorption
Titration through 0.45p MF
References to be Used
Std. Meth.
12th Ed.
(1965)

This M
This M
p. 226-228
p. 516

This N

This N
ASTM Stds.
Part 23 !
(1968) !
E
inual
inual
p. 284
p. 517

anual

anual

*


*

*
:(See USGS Reference, last page of index)

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                                      FWPCA METHODS FOR CHEMICAL ANALYSIS
                                             OF WATER AND WASTES

Parameter

Selenium, Total ( g/1)
, Dissolved ( g/1)
Silica, Total (yg/1)
, Dissolved (ug/1)
Sodium, Total (mg/1)
, Dissolved (mg/1)
Solids, Total (mg/1)
, filterable
, non-filterable
, Volatile (mg/1)
Specific Conductance
Sulfate (mg/1)
Sulfide (mg/1)

Storet
Number

.
01145
00955
00930
00500
00515
00530
00505
00095
00945
00745

Method
i
Diaminobenzidiue
Filtration through 0.45p MF
1
Molybdate
Filtration through 0.45y MF
Atomic Absorption
Filtration through 0.45y MF
Gravimetric, 105 C
Filtration through glass fiber, 180C
Glass-fiber filtration, 105C
Gravimetric, 550C
Wheatstone Bridge
Turbidimetric
Technicon - Barium chloranilate
lodometric
Referen
Std. Meth.
12th Ed.
(1965)

p. 251-253

This N
This M
p. 425
p. 280
p. 291-293
This M
p. 428
ces to be Us
ASTM Stds.
Part 23
(1968)



anual
mual
p. 183
p. 56-58
mual

ed
USGS

*
*
*

*

*
(See USGS Reference,  last  page  of index)

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                                          FWPCA METHODS FOR CHEMICAL ANALYSIS
                                                 OF WATER AND WASTES
          Parameter
Storet
Number
                 Method
Std. Meth.
12th Ed.
 (1965)
                                                                                                References to be Used
 ASTM Stds.
 Part 23
 (1968)
USGS
 Temperature (C)
 00010
Mercury, dial, or thermistor
p. 311
 Threshold Odor - 60C
                - Room Temp.
 00085
Dilution series
Dilution series
p 304
 Turbidity, Nephelometric (JCU)
 00070
Hach 2100 or equivalent
      This MJ
nual
 Zinc, Total (ug/1)
     , Dissolved (ug/1)
 01090
Atomic Absorption
Filtration through 0.45u MF
      This Mi
nual
Techniques of Water Resources Investigations of the U.S. Geological Survey, Book 5, Chap AI: Laboratory Analysis
 of Water, Dissolved Minerals and Gases (to be published)

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                          Table  II - Sample Preservation
       Parameter

Acidity-Alkalinity

Biochemical Oxygen Demand

Calcium

Chemical Oxygen Demand

Chloride

Color

Cyanide

Dissolved Oxygen

Fluoride

Hardness

Metals, Total

Metals, Dissolved

Nitrogen, Ammonia

Nitrogen, Kjeldahl

Nitrogen, Nitrate - Nitrite

Oil and Grease

Organic Carbon

pH

Phenolics



Phosphorus
   Preservative

Refrigeration at 4C

Refrigeration at 4C

None required

2 ml H2S04 per liter

None required

Refrigeration at 4C

NaOH to pH 10

Determine on site

None required

None required

5 ml HNOg per liter

Filtrate: 3 ml 1:1 HN03 per liter

40 mg HgCl2 per liter - 4C

40 mg HgCl2 per liter - 4C

40 mg HgCl- per liter - 4C

2 ml H2S04 per liter - 4C

2 ml H2S04 per liter (pH 2)

Non e avai 1 ab 1 e

1.0 g CuS04 + H3P04 to

pH 4.0 - 4C

40 mg HgCl2 per liter - 4C
    Maximum
Holding Period

 24 hours

  6 hours
  7 days



 24 hours

 24 hours

 No holding
  6 months

  6 months

  7 days

 Unstable

  7 days

 24 hours

  7 days



 24 hours



  7, days

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                          Table II - Sample Preservation
                                     (continued)


                                                                         Maximum
        Parameter                   Preservative                     Holding Period

Solids                          None available                           	

Specific Conductance            None required                            	

Sulfate                         Refrigeration at 4C                   7 days

Sulfide                         2 ml Zn acetate per liter              7 days

Threshold Odor                  Refrigeration at 4C                  24 hours

Turbidity                       None available                           	
References:

   Jenkins,  David,  "A Study of Methods  Suitable for the Analysis and Preserva-
     tion of Phosphorus Forms in an Estuarine Environment."  Report for the
     Central Pacific River Basins Project,  Southwest Region,  FWPCA (1965).

   Jenkins,  David,  "A Study of Methods  for  the Analysis and Preservation of
     Nitrogen Forms in an Estuarine Environment."  Report for Central Pacific
     River Basins Project, Southwest Region,  FWPCA (1965).

   Howe, L.  H.  and Holley, C. W.  "Comparisons of Mercury (II) Chloride and
     Sulfunic Acid as Preservatives for Nitrogen Forms in Water Samples."
     Env. Sci.   Techn. 3:478 (1969).

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                             ACIDITY

1.   Scope and Application
    1.1  The method recommended is  identical  to the  procedure des-
         cribed in ASTM Standards,  Part  23, pp  155-158,  except that
         the sample is  titrated to  a final pH of 8.3 and results  re-
         ported as mg/1 CaCO .
                            O
    1.2  This method is not  applicable to analysis of acid samples
         from mine drainage.   It is the  decision of  the  AQC staff to
         delay the method selection for  measurement  of acidity in
         acid mine drainage  samples until such  time  that a more com-
         prehensive review of the problem can be made.
    1.3  Methods for analysis of mine drainage  samples for all con-
         stituents contributing to  acidity of such samples may be
         selected at the option of  the respective laboratory directors,


2.   Calculation
    2.1  Acidity is reported as calcium  carbonate CaCO,  according to
                                               >       o
         the following  formula:
               Acidity  as mg/1 CaCO  = A x N  x  50,-OOP
                                          ml  sample
         where:
         A - ml of base used for titration
         N = normality  of base


3.   Precision
    3.1  A synthetic sample  containing  21 mg/1  acidity as CaCO, was
         analyzed by 55 laboratories with a  standard deviation of

         1.73 mg/1.

                                11

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                         TOTAL ALKALINITY




                 (Automated Methyl Orange Method)








1.   Scope and Application




    1.1  This automated method is applicable to surface and saline




         waters.  The applicable range is 10 to 200 mg/1 as CaCO,.








2.   Summary of Method




    2.1  Methyl orange is used as the indicator in this method be-




         cause 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 color change directly proportional to the amount of alka-



         linity.








3.   Sample Handling and Preservation




    3.1  Sample should be refrigerated at 4C and run as soon as




         practical.








4.   Interferences




    4.1  No significant interferences.








5.   Apparatus




    5.1  Technicon AutoAnalyzer  consisting of:
                                12

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                                                     (Total  Alkalinity)









         5.1.1   Sampler I.




         5.1.2   Manifold.




         5.1.3   Proportioning pump.




         5.1.4   Colorimeter equipped with  15  mm tubular flow cell




                and 550 my  filters.




         5.1.5   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 1.0 liter of pH 3.1




         buffer to 200 ml methyl orange solution and mix well.   Stable




         for 24 hours.




    6.4  Stock  Solution:  Dissolve 1.0000  g of pre-dried anhydrous




         sodium carbonate in distilled  water  and dilute to 1.0 liter.




         1.0 ml = 1.00 mg Na2C03.



         6.4.1   Prepare a series of standards by diluting suitable




                volumes of stock solution  to  100.0 ml with distilled




                water.  The following dilutions are suggested:
                                 13

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                                                      (Total Alkalinity)
ml of
Stock
Solution
1.
2.
4.
6.
8.
10.
14.
18.
20.
0
0
0
0
0
0
0
0
0

Cone, mg/1
10
20
40
60
80
100
140
180
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.
                                 14

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                                                     (Total Alkalinity)









"9.   Precision  and Accuracy




     9.1   In a  single  laboratory (AQC),  using surface water samples




          at concentrations  of 15,  57,  154,  and 193 mg/1 as CaC03, the




          standard deviation was 0.5.




     9.2   In a  single  laboratory (AQC),  using surface water samples




          at concentrations  of 31 and 149 mg/1 as CaCO.j, recoveries




          were  100% and 99%, respectively.








                              References




 1.   Technicon  AutoAnalyzer  Methodology, Bulletin 1261, Technicon Con-




     trols,  Inc.,  Chauncey,  N.Y.  (1961).




 2.   Standard-Methods,  APHA, 12th Ed.,  p. 48, New York, N.Y.  (1965).
                                 15

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  LARGE MIXING COILS
          oooooooo
'i'i'l'I' '  '!'
1/2 DELAY COIL
                   *-  WASTE -*
                                   PURPLE
                                   GREEN
RED
                                    BLUE
                                                    SAMPLER 1

                                                   SAMPLE
                                                               CONTINUOUS FILTER
                                                   AIR
                                                   BUFFER + INDICATOR
                                           B^    WASTE
                              PROPORTIONING PUMP
             -il?
                                  2X
                COLORIMETER    RECORDER
             15mm TUBULAR f/c
              550 mn FILTERS
                                                          SAMPLING TIME: 2.0 MINUTES
                                                          WASH TUBES: ONE
              FIGURE 1.  ALKALINITY  MANIFOLD

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                   BIOCHEMICAL  OXYGEN  DEMAND









1.   Scope and Application




    1.1  It is the opinion  of the  Analytical Quality  Control  Program




         and its advisors that  present BOD test  procedures  are in-




         herently nonreproducible  and  that the unpredictable  nature




         of the test  results  make  their interpretation  difficult.




         Therefore, no specific procedure has been selected as the




         FWPCA standard test  for Biochemical Oxygen Demand.




    1.2  The traditional BOD  test  is empirical,  employing standard-




         ized laboratory conditions in an attempt  to  yield  repro-




         ducible results.   Since the actual environmental conditions




         of temperature, biological population,  water movement,




         sunlight, and oxygen concentrations cannot be  accurately




         reproduced in the  laboratory, the results obtained from the




         empirical test have  little relationship to stream  oxygen




         demands.




    1.3  The test may be useful for determining  the relative  waste




         loadings to  treatment  plants  and the degree  of oxygen demand




         removal provided by  primary treatment.   Because of the com-




         plex changes in oxygen-demanding materials during  secondary




         treatment, the use of  the test to measure secondary  plant




         efficiency is questionable.




    1.4  At the present time, there are no other procedures that




         adequately replace the BOD test.  There are, however, other
                                17

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                                                              (BOD)


         measurements available which furnish useful information.

         These tests include Total Organic Carbon (TOC)  and Chemical

         Oxygen Demand (COD).



2.   Procedure

    2.1  Directions for conducting the BOD test are found in:

           Standard Methods for the Examination of Water and
           Wastewater, 12 Edition (1965), pp. 415-421.

           ASTM Standards (1968) Part 23, Water; Atmospheric
           Analyses, pp. 727-732.

    2.2  Determinations of dissolved oxygen in the BOD test may be

         made by use of Dissolved Oxygen (Probe Method)  or Dissolved

         Oxygen (Modified Winkler with Full-Bottle Technique) in this

         manual.



3.   Precision and Accuracy

    3.1  In 34 laboratories, the standard deviation of the BOD test,

         using a glucose-glutamic acid mixture, was 31  mg/1 at a mean

         BOD concentration of 184 mg/1.  In a single laboratory, the

         precision was 11 mg/1 at a BOD of 218 mg/1 (Analytical Refer-

         ence Service, PHS).

    3.2  There is no method available to determine the accuracy of the

         BOD test.
                                 18

-------
                      CHEMICAL OXYGEN DEMAND




                            (Low Level)






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 for 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) sulfuric acid solution.  The excess




         dichromate is titrated with standard ferrous ammonium




         sulfate using orthophenanthroline ferrous complex (ferroin)




         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.
                                 19

-------
                                                      (Chemical Oxygen Demand)
                                                             (Low Level)
    3.3  Samples may be preserved with sulfuric acid at a rate of

         2 ml of cone.  H2S04 per liter of sample.

4.  Interferences

    4.1  Traces of organic material either from the glassware or

         atmosphere may cause a gross, positive error.

         4.1.1  Extreme care should be exercised to avoid inclusion

                of organic materials in the distilled water used

                for reagent preparation or sample dilution.

         4.1.2  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 sulfuric acid addition step.

    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 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 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.
                                     20

-------
                                                       (Chemical Oxygen Demand)
                                                              (Low Level)
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 (0.025 N) - Dissolve

         12.259 g ICCr-O-, primary standard grade, previously dried

         at 103C for two  hours, in distilled water and dilute to

         1000 ml.  Mix this solution thoroughly then dilute 100 ml

         to one liter with distilled water.

    6.3  Sulfuric acid reagent - Cone. H-SC"  containing 23.5 g silver

         sulfate, Ag_SO.,  per 9 Ib. bottle (one to two days required

         for dissolution).

    6.4  Standard ferrous  ammonium sulfate (0.025 N) - Dissolve 98 g

         of Fe(NH4)2(S04)2.6H20 in distilled water.  Add 20 ml of cone.

         H2SO., cool and dilute to 1000 ml.  Dilute 100 ml of this

         solution to one liter with distilled water.  This solution

         must be standardized daily against JCCr^CL solution.

         6.4.1  Standardization - To 15 ml of distilled water add

                10 ml of 0.025 N Kr2Cr20  solution.  Add 20 ml of

                H_SO. and cool.  Titrate with ferrous ammonium sulfate

                using 1 drop of ferroin indicator.  The color change is

                sharp, going from blue-green to reddish-brown.

                      Normality =  (ml KCr0 ) (0.025)
                                   ml Fe (NH4)2(S04)2
                                    21

-------
                                                      (Chemical Oxygen Demand)
                                                             (Low Level)
    6.5  Mercuric sulfate - Powdered HgSCL.

    6.6  Phenanthroline ferrous sulfate (ferroin) indicator solution -

         Dissolve 1.48 g of 1-10-(ortho)-phenanthroline monohydrate,

         together with 0.70 g of FeSCK.TH-O in 100 ml of water.   This

         indicator may be purchased already prepared.

    6.7  Silver sulfate - Powdered Ag^SO..

    6.8  Sulfuric acid (sp. gr. 1.84) - Concentrated H2S04.

7.   Procedure

    7.1  Place several boiling stones in the reflux flask, followed by

         1 g of HgSO..  Add 5.0 ml cone. H SO  (6.8); swirl until mercuric

         sulfate has dissolved.  Place reflux flask in an ice bath and

         slowly add, with swirling, 25.0 ml of 0.025 N K Cr 0 .   Now

         add 70.0 ml of sulfuric acid-silver sulfate solution (6.3) to

         the cooled reflux flask, again using slow addition with swirling

         motion.

    7.2  With the reflux flask still in the ice bath, place 50.0 ml of

         sample or a sample aliquot diluted to 50.0 ml into the  reflux

         flask.  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 con-

         denser.  Attach the flask to the condenser and start the cooling

         water.

    7.3  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 waste water of

         constant or known composition may be determined and a shorter

         period of refluxing may be permissible.


                                   22

-------
                                                  (Chemical Oxygen Demand)
                                                         (Low Level)

    7.4  Allow the flask to cool and wash down the condenser with

         about 25 ml of 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 water.  Dilute the

         acid solution to about 300 ml with water and allow the

         solution to cool to about room temperature.  Add 8 to 10

         drops of phenanthroline ferrous sulfate solution to the

         solution and titrate the excess dichromate with 0.025 N

         ferrous ammonium sulfate solution to the end point.  The

         color change will be sharp, changing from a blue-green to a

         reddish hue.

    7.5  Blank - Simultaneously run a blank determination following

         the details given in 7.1 and 7.2, but using low COD water

         in place of the sample.

8.   Calculation

    8.1  Calculate the COD in the sample in mg/1 as follows:

              COD, mg/liter = (A - B) N x 8000
                                      S

         where:

         A = milliliters of Fe  (NH^^CSO^)~ solution required

             for titration of the blank,
                               .!
         B = milliliters of Fe (^4)2(804)2 solution required

             for titration of the sample,

         N = normality of the Fe (NI^) 2 (SO^)-solution, and

         S = milliliters of sample used for the test.
                                23

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                                                      (Chemical Oxygen Demand)
                                                             (Low Level)
9.  Precision

    9.1  The precision of the low level test described in the

         foregoing material has not been determined by collaborative

         testing.
                                  24

-------
                        CHEMICAL OXYGEN DEMAND




                    (High Level  for Saline  Waters)








1.   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.








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) sulfuric acid solution.  The excess di-




         chromate is titrated with standard ferrous ammonium sulfate




         using orthophenanthroline ferrous  complex  (ferroin) as an




         indicator.








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  Biologically active samples should be tested as soon as pos




         sible.  Samples containing settleable material should be




         well mixed, preferably  homogenized, to permit removal of




         representative aliquots.




    3.3  Samples are preserved by the addition of 2 ml of cone. ^SO




         per liter of sample.
                                  25

-------
                                                      (COD - High Level for
                                                               Saline Waters)
4.   Interferences

    4.1  Traces of organic material either from the glassware or atmos-

         phere may cause a gross, positive error.

         4.1.1  Extreme care should be exercised to avoid inclusion of

                organic materials  in the distilled water used for

                reagent preparation or sample dilution.

         4.1.2  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 sulfuric acid addition step.

    4.3  Chlorides are quantitatively oxidized by dichromate and re-

         present a positive interference.  Mercuric sulfate is added

         to the digestion flask to complex the chlorides, thereby

         effectively eliminating the interference on all but brine

         samples.



5.   Apparatus

    5.1  Reflux apparatus - Glassware should consist of a 500 ml Erlen-

         meyer 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.
                                   26

-------
                                                       (COD - High Level for
                                                                Saline Waters)
6.  Reagents

    6.1  Standard potassium dichromate solution,  (0.25 N):   Dissolve

         12.2588 g of K2Cr207,  primary standard grade, previously dried

         for 2 hours at 1Q3C in water and dilute to 1.0 liter.

    6.2  Sulfuric acid reagent:   Cone. H2S04 containing 23.5 g silver

         sulfate, Ag2SC>4,  per 9 Ib.  bottle (1 to 2 days required for

         dissolution).

    6.3  Standard ferrous  ammonium sulfate, 0.250 N:  Dissolve 98 g of

         Fe(NH4)2(S04)2.6H20 in distilled water.   Add 20 ml of cone.

         H2S04, cool and dilute to 1000 ml.  This solution  must be

         standardized against the standard potassium dichromate solution

         daily.

         6.3.1  Standardization:  Dilute 25.0 ml of standard dichromate

                solution to about 250 ml with distilled water.  Add 75

                ml cone, sulfuric acid.  Cool, then titrate with ferrous

                ammonium sulfate titrant, using 10 drops of ferroin

                indicator.

                     Normality = (ml K2Cr20?) (0.25)
                                  ml Fe(NH4)2(S04)2

    6.4  Mercuric sulfate  - Powdered HgSCh.

    6.5  Phenanthroline ferrous sulfate (ferroin) indicator solution -

         Dissolve 1.48 g of 1-10-(ortho)-phenanthroline monohydrate,

         together with 0.70 g of FeS04.7H20 in 100 ml of water.   This

         indicator may be  purchased already prepared.
                                  27

-------
                                                       (COD -  High Level  for
                                                                Saline Waters)
    6.6  Silver sulfate - Powdered Ag-SCK.

    6.7  Sulfuric acid (sp. gr. 1.84) - Concentrated H-SO..



7.   Procedure

    7.1  Pipet a 50 ml aliquot of sample not to exceed 800 mg/1 of COD

         into a 500 ml, flat bottom, Erlenmeyer flask.  Add 25 ml of

         0.25 N K^C^Oy, then 5.0 ml of cone. t^SO, (containing.no

         silver sulfate).  Add HgSO, in the ratio of 10 mg to 1 mg

         chloride, based upon the mg of chloride in the sample aliquot.

         Swirl until all the mercuric sulfate has dissolved.  Care-

         fully add 70 ml of sulfuric acid-silver sulfate solution 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).

         7.1.1  If volatile organics are present in the sample, use

                an Allihn condenser and add the sulfuric 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
                                  28

-------
                                                       (COD - High Level for
                                                               Saline Waters)
         and  condenser joint with 25 ml of distilled water.  Remove the

         condenser and carefully add to the flask 175 ml of distilled

         water  so that the total volume is 350 ml.  Cool to room tem-

         perature .

    7.4   Titrate with standard ferrous ammonium  sulfate using  10 drops

         of ferroin  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 ml, 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.


*Burns,  E.  R.,  Craig, N., Journal WPCF, Vol. 37, pp 1716-1721, 1967.
                                  29

-------
                                                       (COD - High Level for
                                                                Saline Waters)
8.   Calculation

    8.1               mg/1 COD = (A - B) C x 8000 - D x 1.20
                                     ml sample

         where:

         COD = chemical oxygen demand from dichromate

           A = ml Fe(NH4)2(S04)2 for blank;

           B = ml Fe(NH.)2(S04)2 for sample;

           C = normality of Fe(NH4)2(S04)2;

           D = chloride correction from curve (step 7.7).

        1.20 = compensation factor to account for the extent of

               chloride oxidation which is dissimilar in systems

               containing organic and nonorganic material.



9.   Precision and Accuracy

    9.1  Precision and accuracy data are not available at this time.
                                  30

-------
                             CHLORIDE




                  (Automated Ferricyanide Method)








1.  Scope and Application




    1.1  This automated method is applicable on surface water, domestic




         and industrial wastes, and saline waters.   The applicable




         range is 1 to 250 mg Cl/1.  Approximately 15 samples per hour




         can be analyzed.




2.  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 ferric ion,




         the liberated SCN forms highly colored ferric thiocyanate, in




         concentration proportional to  the original chloride concen-




         tration.




3.  Sample Handling and Preservation




    3.1  No special requirements.




4.  Interferences




    4.1  No significant interferences.




5.  Apparatus




    5.1  Technicon AutoAnalyzer consisting of:




         5.1.1  Sampler I.




         5.1.2  Continuous filter.




         5.1.3  Manifold.




         5.1.4  Proportioning pump.
                                   31

-------
                                                            (Chloride)


         5.1.5  Colorimeter equipped with 15 mm tubular flow cell
                and 480 my filters.
         5.1.6  Recorder


6.  Reagents
    6.1  Ferric Ammonium Sulfate:  Dissolve 60 g of FeNH  (SO ) .12 HO
         in approximately 500 ml distilled water.  Add 355 ml of cone
         HNO- and dilute to 1 liter with distilled water.  Filter.
    6.2  Saturated Mercuric 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 (0.141 N NaCl):  Dissolve 0.8241 g of
         pre-dried NaCl in distilled water.  Dilute to 1 liter.
         1 ml  =  0.5 mg Cl".
         6.3.1  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
                         0.2                   1.0
                         1.0                   5.0
                         2.0                   10
                         4.0                   20.
                         8.0                   40
                        15.0                   75
                        20.0                  100
                        30.0                  150
                        40.0                  200
                        50.0                  250
                                   32

-------
                                                          (Chloride)


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 concen-

         trations.   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, using  surface  water  samples at  concentra-

         tions of 1, 100, and 250  mg  Cl~/l, the standard  deviation was

         -0.3 (AQC Laboratory).
                                   i
                               33

-------
                                                           (Chloride)





    9.2  In a single laboratory (AQC),  using surface water samples at




         concentrations of 10 and 100 mg Cl/1. recoveries were 97% and




         104%, respectively.










                           Reference







1.   J. E. O'Brien, "Automatic Analysis  of Chlorides in Sewage,"




    Wastes Engr., 33, 670-672 (Dec.  1962).
                               34

-------
                                                                                         CONTINUOUS  FILTER
co
01
                                                                              Fe NH4(S04J2
                                                                               (SCNJ2
                                                            PROPORTIONING
                                                                PUMP
                        COLORIMETER
                   15mm TUBULAR f/c
                      480mjJ FILTERS
SAMPLING  TIME:  2.0 MINUTES
WASH TUBES: ONE
                                        FIGURE 1.  CHLORIDE MANIFOLD

-------
                            COLOR
1.  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.








         Note - The Spectrophotometric and Tristimulus 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.








2.  Summary of Method




    2.1  Color is measured by visual comparison of the sample with




         platinum-cobalt  standards.   One unit of color is  that pro-




         duced by 1 mg/1  platinum in the form of the chloroplatinate




         ion.








3.  Interference




    3.1  Since very slight amounts  of turbidity interfere  with the




         determination, samples  showing visible turbidity  should  be




         clarified by centrifugation.
                                 37

-------
                                                             (Color)



4.  Sample Handling and Preservation

    4.1  Representative samples shall be taken in scrupulously

         clean glassware.

    4.2  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.


5.  Apparatus

    5.1  Nessler tubes - Matched, tall form, 50 ml capacity.


6.  Reagents

    6.1  Standard chloroplatinate solution.  Dissolve 1.246 g potassium

         chloroplatinate, K PtCl,, (equivalent to 0.500 g metallic Pt)

         and 1 g crystalline cobaltous chloride, CoCl-^tLO, in distilled

         water containing 100 ml of cone. HC1.  Dilute to 1 liter with

         distilled water.  This standard solution is equivalent to 500

         color units.


7.  Preparation of Standards

    7.1  Prepare standards in increments from 5 to 70 units.

         The following series is suggested:

         ml of Standard Solution
         Diluted to 50.0 ml                      Color in
         with Distilled Water              Chloroplatinate Units

                 0.0                                0
                 0.5                                5
                 1.0                               10
                 1.5                               15
                 2.0                               20
                 2.5                               25
                 3.0                               30
                 3.5                               35
                 4.0                               40
                 4.5                               45
                 5.0                               50
                 6.0                               60
                 7.0                               70

                                  38

-------
                                                              CColor)








    7.2  Protect these  standards  against  evaporation and




         contamination  by use  of  clean, inert stoppers.








         Note -   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 re-




         flected upward through the columns  of liquid.  If turbidity




         has not been removed  by  the  procedure given in 8.2, report




         the color as "apparent color."   If  the color exceeds  70




         units,  dilute  the sample with distilled water in known




         proportions until the color  is within the range  of the standards.




    8.2  True color - Remove turbidity by centrifuging the sample  until




         the supernatant is clear. Compare  the centrifuged sample with




         distilled water to insure that turbidity has been removed.  If




         the sample is  clear,  then compare with standards as given in 8.1,








9.   Calculation




    9.1  Calculate the  color units by means  of the following equation:





                                      A x 50
                       Color units =
                                        V
                                  39

-------
                                                             (Color)
    Where:  A = estimated color of diluted sample.

            V = ml sample taken for dilution.

    9.2  Report the results in 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

    10.1  Precision and accuracy data are not available at this

          time.



    Reference - Standard Methods for the Examination of Water

                and Wastewater, 12th Edition, 127-129, 1965.

                APHA Inc., N.Y.
                                   40

-------
                              CYANIDE






1.   Scope and Application




    1.1  This method is applicable to the determination of cyanide




         in surface waters,  domestic and industrial wastes, and




         saline waters.




    1.2  The titration procedure using silver nitrate with p-




         dimethylamino-benzalrhodanine indicator is used for




         measuring concentrations of cyanide exceeding 1 mg/1




         (0.2 mg/200 ml of absorbing liquid).




    1.3  The colorimetric procedure is used for concentrations




         below 1 mg/1 of cyanide and is sensitive to about 5 yg/1.




2.   Summary of Method




    2.1  The cyanide as hydrocyanic acid (HCN) is released from




         metallic cyanide complex ions by means of a reflux-distilla-




         tion operation and absorbed in a scrubber containing sodium




         hydroxide solution.   The cyanide ion in the absorbing




         solution is then determined by volumetric titration or




         colorimetrically.




    2.2  The colorimetric measurement employs the pyridine-pyrazolone




         reaction in which the cyanide is coupled with free chlorine




         to form cyanogen chloride and then with pyridine to a




         glutaconic aldehyde.   The aldehyde then reacts with 1-phenyl-



         3-methyl-5-pyrazolone to form a highly colored blue dye.
                                41

-------
                                                 (Cyanide)








    2.3  The titrimetric 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 and mercuric ions.




4.   Sample Handling and Preservation




    4.1  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 containers.




    4.2  Samples must be preserved with 20 ml of a 1 N sodium




         hydroxide per liter of sample at the time of collection.




    4.3  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 temperatures at 4C.




5.   Interferences




    5.1  Interferences are eliminated or reduced by using the distillate



         obtained with the preliminary screening procedure.




    5.2  Sulfides are an interference that should be removed prior to




         distillation.  Remove sulfides with pH adjustment to >11,
                                 42

-------
                                                  ( Cyanide)








         addition of lead carbonate and mixing.   Filter sample to




         remove lead sulfide.   Repeat until no more lead sulfide




         is formed as evidenced by whiteness of the lead carbonate.




    5.3  Oxidizing substances  interfere and should be treated with




         ascorbic 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.




    6.2  Microburet, 5.0 ml (for titration).




    6.3  Spectrophotometer suitable for measurements at 620 my with




         a 1.0 cm cell or larger.




7.   Reagents




    7.1  Sodium hydroxide solution, 1 N.  Dissolve 40 g of NaOH in




         distilled water, and dilute to a liter with distilled water.




    7.2  Lead carbonate.




    7.3  Ascorbic acid.




    7.4  Mercuric chloride solution.  Dissolve 34 g HgCl? in 500 ml




         distilled water.




    7.5  Magnesium chloride solution.  Dissolve 51 g MgCl~.6H70 in




         100 ml distilled water.




    7.6  Sulfuric acid,  concentrated.




    7.7  Sodium dihydrogenphosphate, 1 M.  Dissolve 138 g of




         NaH-PO-.H 0 in a liter of distilled water.  Refrigerate this



         solution.
                                43

-------
ALLIHN CONDENSER*

AIR INLET
CONNECTING TUBING
ONE LITER	
BOILING FLASK
                                    SUCTION
                   GAS ABSORBER
                 FIGURE 1
   CYANIDE DISTILLATION APPARATUS
                      45

-------
   COOLING WATER
   INLET TUBE'
SCREW CLAMP
     I
        HEATER
                                  TO LOW VACUUM
                                     SOURCE
                               - ABSORBER
                        ^  DISTILLING FLASK
                  O
             FIGURE 2
CYANIDE  DISTILLATION  APPARATUS
                 47

-------
                                                  (Cyanide)








 7.8  Stock cyanide  solution.   Dissolve  2.51  'g of KCN and 2  g




      KOH in a liter of distilled water.   Standardize with




      0.0192 N AgNO,.   Dilute  to  appropriate  concentration




      so that 1 ml  = 1  mg CN~.




 7.9  Standard cyanide  solution,  intermediate.  Dilute 10 ml




      of stock (1 ml =  1 mg CN) to a liter of distilled water




      (1 ml = 10 yg).




7.10  Standard cyanide  solution.   Prepare fresh daily by




      diluting 100  ml of intermediate cyanide solution to a




      liter of distilled water and store in a glass  stoppered




      bottle.  One  ml = 1.0 yg CN (1.0 ppm).




7.11  Standard silver nitrate  solution,  0.0192 N.  Prepare by




      crushing approximately 5 g  AgNO, crystals and drying to




      constant weight at 40C.  Weigh out 3.2647 g of dried  AgNO ,




      dissolve in water, and dilute to liter  (1 ml = 1 mg CN).




7.12  Rhodanine indicator.   Dissolve 20  mg of p-dimethylamino-




      benzalrhodanine in 100 ml of acetone.




7.13  Chloramine T  solution.  Dissolve 1.0 g  of white water




      soluble Chloramine T in  100 ml of  distilled water and




      refrigerate until ready  to  use. Prepare fresh weekly.




7.14  Pyridine-pyrazolone solution.




      7.14.1  One-phenyl-3-methyl-5-pyrazolone reagent.  Weigh




              0.25  g of 3-methyl-l-phenyl-2-pyrazolone-5-one and
                             49

-------
                                                     (Cyanide)








                 dissolve in 50 ml of distilled water by heating




                 to 60C.  Cool after reagent is in solution.




         7.14.2  Three,3'-Dimethyl-1,1'-diphenyl-4,4'-bi-2




                 pyrazolone - 5,5' dione (bispyrazolone).   Dissolve




                 0.01 g of bispyrazolone in 10 ml of pyridine.




         7.14..3  Pour solution 7.14.1 through  nonacid-washed




                 filter paper.  Collect the filtrate.   Through the




                 same filter paper pour solution 7.14.2 collecting




                 the filtrate in the same container as filtrate




                 from 7.14.1.  Mix until the filtrates are homoge-




                 neous.  The mixed reagent develops a pink color but




                 this does not affect the color production with




                 cyanide if used within 24 hours of preparation.




8.  Procedure




    8.1  Place 500 ml of sample, or an aliquot diluted to 500 ml in




         the 1-liter boiling flask.  Add 50 ml of 1 N sodium




         hydroxide (7.1) to the absorbing tube and dilute if




         necessary with distilled water to obtain an adequate depth




         of liquid in the absorber.  Connect the boiling flask,




         condenser, absorber and trap in the train.




    8.2  Start a slow stream of air entering the boiling flask by




         adjusting the vacuum source.  Adjust the vacuum so that




         approximately 1 bubble of air per second enters the boiling
                                 50

-------
                                                 (Cyanide)








     flask through the  air  inlet  tube.   (Caution:   The




     bubble rate will not remain  constant after the reagents




     have been added and while  heat  is  being applied to the




     flask.  It will be necessary to readjust the  air rate




     occasionally to prevent the  solution in the boiling flask




     from backing up into the air inlet tube.)




8.3  Add 10 ml of mercuric  chloride  solution (7.4) and 40 ml




     of magnesium chloride  solution  (7.5) through  the air inlet




     tube.  Rinse the air inlet tube with a few ml of distilled




     water and allow the air flow to mix the contents of the




     flask for at least 3 minutes.




8.4  Slowly add 25 ml of concentrated sulfuric acid (7.6)




     through the air inlet  tube and  rinse with distilled water.



8.5  Heat the solution  to boiling, taking care to prevent  the




     solution from backing  up into and overflowing from the air




     inlet tube.  Reflux for one  hour.   Turn off heat and




     continue the airflow for at  least 15 minutes.  After cooling




     of 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 and bring up to  volume with distilled water washings




     from the absorber  tube.  Cool the volumetric flask in an ice




     bath until the temperature of the solution is 5C.
                             51

-------
                                                      (Cyanide)



8.7  Withdraw 50 ml of the solution from the volumetric flask

     and transfer to a 100-ml volumetric flask.  Add 10 ml of

     sodium phosphate solution (7.7) and 0.2 ml of Chloramine

     T solution (7.13) and mix.  Add an additional 5 ml of the

     sodium phosphate (7.7), followed by 5 ml of mixed pyridine-

     pyrazolone solution, (7.14.3), bring to mark with distilled

     water and mix.  Allow 40 minutes for color development.

8.8  Read absorbance at 620 my using at least a 1.0 cm cell.

8.9  Prepare a series of standards by diluting suitable volumes

     of standard solution to 500.0 ml with distilled water as

     follows:

     ml of Standard Solution        Cone., When Diluted to
       (1.0 ml = 1 yg CN)              500 ml, mg/1 CN

              0 (Blank)                      0
              5.0                            0.01
             10.0                            0.02
             20.0                            0.04
             50.0                            0.10
            100.0                            0.20
            150.0                            0.30
            200.0                            0.40

     8.9.1  Standards must be treated in the same manner as the

            samples, as outlined in 8.1 through 8.8 above.

     8.9.2  Prepare a standard curve by plotting absorbance of

            standards vs. cyanide concentrations.

     8.9.3  Subsequently, at least two standards  (a high and a

            low) should be treated as in 8.9.1 to verify standard

            curve.  If results are not comparable (20%), a com-

            plete new standard curve must be prepared.
                             52

-------
                                                          (Cyanide)








          8.9.4  To check the efficiency of the sample distillation,




                 add an increment of cyanide from either the inter-




                 mediate standard (7.9)  or the working standard (7.10)




                 to insure a level of 10 yg/1 or a significant  increase




                 in absorbance value.  Proceed with the analysis  as  in




                 Procedure (8.) using the same flask and system from



                 which the previous sample was just distilled.




    8.10  Alternatively, if the sample contains more than 1  mg  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 benzalrhodanine indicator.



    8.11  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 the sample.




    8.12  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.  A 5 or 10  ml  micro-




          buret may be conveniently used to obtain a more precise




          titration.



9.  Calculation




    9.1  Using the colorimetric procedure, calculate concentration of




         CN, mg/1, directly from prepared standard curve.




    9.2  Using the titrimetric procedure, calculate concentration of




         CN as follows:
                                 53

-------
           CN, mg/1 =
                                                            (Cyanide)







                             (A-B) x 1000         	250	
                       Vol. of original sample   Vol. of aliquot titrated



           where:




           A = volume of AgNOg for titration of sample.




           B = volume of AgNOj for titration of blank.








10.  Precision and Accuracy




     10.1  A synthetic sample prepared by the Analytical Reference Ser-




           vice  (PHS) at a known concentration of 0.02 mg/1 CN was analyzed




           by 47 analysts; the data showed a standard deviation of 0.035




           mg/1 for the titrimetric procedure and 0.020 mg/1 for the colori-




           metric procedure.  Similarly, at a concentration of 1.10 mg/1




           of CN, the data showed a standard deviation of 0.333 mg/1 for




           the titrimetric procedure and 0.306 mg/1 for the colorimetric




           procedure.








                               References
1.  Bark, L. S., and Higson, H. G.  Investigation of reagents for the




    colorimetric determination of small amounts of cyanide.  Talanta,




    2:471-479 (1964).




2.  Ely, C. T.  Recovery of cyanides by modified Serfass distillation.




    Journal Water Pollution Control Federation, 40:848-856 (1968).
                                   54

-------
                         DISSOLVED OXYGEN




           (Modified Winkler With Full-Bottle Technique)








1.   Scope and Application




    1.1  This method is  applicable for use with most wastewaters and




         streams that contain nitrite nitrogen and not more than 1




         mg/1 of ferrous iron.   Other reducing or oxidizing materials




         should be absent.   If 1 ml 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 azide modification is not applicable under the following




         conditions:  (a) samples containing sulfite, thiosulfate,




         polythibnate,  appreciable quantities of free chlorine or




         hypochlorite;  (b)  samples high in suspended solids; (c)




         samples containing organic substances which are readily




         oxidized in a highly alkaline solution, or which are oxi-




         dized by free iodine in an acid solution; (d) domestic sewage;




         (3) biological  floes; and (f) where sample color interferes



         with endpoint detection.  In instances where the azide modi-




         fication is not applicable,  a DO probe should be used.








2.   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 sulfuric acid.  The
                                55

-------
                                                       (Dissolved Oxygen)








         initial precipitate of manganous hydroxide, Mn(OH)2,  combines




         with the dissolved oxygen in the sample to form a brown pre-




         cipitate, manganic hydroxide, Mn 0(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 stoichiometrically equivalent




         to the dissolved oxygen in the sample is then titrated with




         sodium thiosulfate.








3.  Interferences




    3.1  There are a number of interferences to the dissolved oxygen




         test, including oxidizing and reducing agents, nitrite ion,




         ferrous iron, and organic matter.




    3.2  Various modifications of the original Winkler procedure for




         dissolved oxygen have been developed to compensate or elimi-




         nate 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 Theriault 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.








4.  Sample Handling and Preservation




    4.1  Where possible, collect the sample in a 300 ml BOD incu-




         bation bottle.  Special precautions are required to avoid
                                 56

-------
                                                 (Dissolved Oxygen)








     entrainment or solution of atmospheric oxygen or dissolution




     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 turbu-




     lence and the formation of bubbles when filling  bottle.




4.4  The sample temperature should be recorded at time of sampling



     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 reagent and then 2 ml




            of alkali azide reagent 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 tem-




            perature of 10 to 20C,  in the dark.
                              57

-------
                                                  (Dissolved Oxygen)








     entrairunent or solution of atmospheric oxygen or dissolution




     of dissolved oxygen.




4.2  Where samples are collected from shallow depths (less than




     five 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 turbu-




     lence and the formation of bubbles when filling bottle.




4.4  The sample temperature should be recorded at time of sampling




     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 4.5.1 or 4.5.2




     below may be employed.




     4.5.1  Add 2 ml of manganous sulfate reagent and then 2 ml




            of alkali azide reagent 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 tem-



            perature of 10 to 20C, in the dark.
                            58

-------
                                                      (Dissolved Oxygen)






         4.5.2  Add 0.7 ml  of concentrated ^864 and 1  ml  sodium



                azide solution (2  g NaN,  in 100 ml  distilled water)



                to the sample in the DO bottle.  Store  sample as in



                4.5.1.      Complete the procedure using 2  ml of



                manganous  sulfate  solution, 3 ml alkali iodide solu-



                tion, and  2 ml of  concentrated 1^504.


    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



         0.1 ml of reagent.






6.   Reagents



    6.1  Manganous sulfate solution:  Dissolve 480  g of manganous



         sulfate (MnSO .4H 0) in distilled water and dilute to 1 liter.



         6.1.1  Alternately, use 400 g of MnSO .2H  0 or 364 g of MnSO .HO
                                              4-   ,                  T-  


                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 at  20C.



    6.2  Alkaline iodide 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
                                 59

-------
                                                  (Dissolved Oxygen)

     distilled water and dilute to 1 liter.   To this solution add
     10 g of sodium azide (NaN ) dissolved in 40 ml of distilled
     water.
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
     10G refrigerator.
     6.4.1  Dry, powdered starch indicators such as "thyodene"
            may be used in place of starch solution.
6.5  Potassium fluoride solution:  Dissolve 40 g KF.2H20 in dis-
     tilled water and dilute to 100 ml.
6.6  Sodium thiosulfate. stock solution. 0.75 N:  Dissnlvfi 186.15 a
     ^28203. SF^O in boiled and cooled distilled water and dilute
     to 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 biniodate.
6.8  Potassium biniodate standard, 0.375 N:  Dissolve 4.873 g
     potassium biniodate, previously dried 2 hours at 103C, in
     1.0 liter of distilled water.  Dilute 250 ml to 1.0 liter for
     0.0375 N biniodate solution.
                            60

-------
                                                      (Dissolved Oxygen)



    6.9  Standardization  of 0.0375  N  sodium thiosulfate:   Dissolve

         2 g 1.0  g  KI  in 100  to  150  ml  distilled  water;  add 10  ml

         of 10% H-SO.  followed by 20  ml  standard potassium biniodate.

         Place in  dark  for 5 minutes, dilute to  300  ml,  and titrate

         with the  standard sodium thiosulfate titrant  to a pale  straw

         color. Add 1-2  ml starch  solution and  continue the titration

         drop by drop until the blue  color disappears.   Run in duplicate.

         Duplicate determinations should agree within  0.05 ml.



7.   Procedure

    7.1  To the sample  collected  in the  BOD incubation bottle, add 2

         ml of the manganous sulfate  solution followed by 2 ml of the

         alkali-iodide-azide reagent, 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. With estuarine-type waters, a

         minimum 2-minute period  of contact with the precipitate

         rather than settling  is  sufficient.  When settling has  produced

         at least  100 ml  of clear supernate, carefully remove the

         stopper and immediately  add  2.0 ml of cone. H-SO. (sulfamic

         acid packets,  3  g may be substituted for  FUSO.) * ' by allowing
(l)Kroner,  R.  C.,  Longbottom,  J.  E.,  Gorman,  R.,  A Comparison of Various
   Reagents Proposed for Use in the Winkler Procedure for Dissolved
   Oxygen,  PHS Water Pollution Surveillance System Applications and
   Development Report #12,  Water Quality Section,  Basic Data Branch,
   July 1964.
                                61

-------
                                                      (Dissolved Oxygen)








         the acid to run down the neck of the bottle,  re-stopper, and




         mix by gentle inversion until the iodine is uniformly dis-




         tributed throughout the bottle.  Complete the analysis within




         45 minutes.




    7.2  Transfer the entire bottle contents by inversion into a 500-ml



         wide mouth Erlenmeyer flask and titrate with 0.0375 N thio-




         sulfate solution (where problems of stability arise, 0.0375  N




         PAO may be substituted as titrant)    to a pale straw color.



         Add 1-2 ml of starch solution or 0.1 g of powdered indicator




         and continue to titrate to the first disappearance of the




         blue color.




    7.3  If ferric iron is present (100 to 200 ppm), add 1.0 ml of




         KF solution before acidification.




    7.4  Occasionally, a dark brown or black precipitate persists in




         the bottle after acidification.  This precipitate will dis-




         solve if the solution is kept for a few minutes longer than




         usual or, if particularly persistent, a few more drops of




         H2S04 will effect dissolution.








8.   Calculation




    8.1  Each ml of 0.0375  sodium thiosulfate titrant is equivalent



         to 1 mg/1 DO when the entire bottle contents are titrated.




    8.2  If the results are desired in milliliters of oxygen gas per




         liter at 0C and 760 mm pressure, multiply mg/1 DO by 0.698.
                                 62

-------
                                                      (Dissolved Oxygen)



    8.3  To express  the  results  as  percent  saturation  at  760 mm

         atmospheric pressure, the  solubility data in  Table  25

         (Whipple &  Whipple  Table,  p.  409,  Standard Methods, 12th

         Edition) may be used.   Equations  for correcting  the solu-

         bilities 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, y (mm Hg),  for the  given T, may be  calculated

         between the temperature of 0 and 30C by:

                    ml/1 DO  = (P -  U)  x 0.678
                                   35  + T

         and between 30 and 50C by:

                    ml/1 DO  = (P -  U)  x 0.827
                                   49  + T



9.   Precision and Accuracy

    9.1  Exact data  are unavailable on  the  precision and accuracy of

         this technique; however, reproducibility is approximately

         0.2 ppm of  DO at the 7.5 ppm  level due to equipment toler-

         ances and uncompensated displacement errors.
                                63

-------
                      DISSOLVED  OXYGEN




                       (Probe Method)








1.   Scope and Application




    1.1  The probe method  for dissolved  oxygen  is  recommended for those




         samples  containing materials which  interfere  with  the modified




         Winkler  procedure such  as  sulfite,  thiosulfate,  polythionate,




         mercaptans,  free  chlorine  or hypochlorite,  organic substances




         readily  hydrolyzed in alkaline  solutions,  free  iodine, in-




         tense color  or turbidity,  biological floes, etc.




    1.2  The probe method  is recommended as  a substitute for the modified




         Winkler  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




         Winkler  procedure in BOD determinations where it is desired to




         perform  non-destructive DO measurements on a  sample.




    1.4  The probe method  may be used under  any circumstances as a sub-




         stitute  for  the modified Winkler procedure provided that the




         probe itself is standardized against the  Winkler 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 scales




         (0 to 10,  0  to 15, 0 to 20 ing/liter, for  example)  with a




         sensitivity  of approximately 0.05 mg/liter.
                                65

-------
                                                      (DO - Probe Method)








2.   Summary of Method



    2.1  The most common instrumental probes for determination of dis-




         solved oxygen in water are dependent upon electrochemical




         reactions.  Under steady-state conditions, the current or




         potential can be correlated with DO concentrations.  Inter-




         facial dynamics at the probe-sample interface are a factor in




         probe response and a significant degree of interfacial turbu-




         lence is necessary.  For precision performance, turbulence




         should be constant.








3.   Sample Handling and Preservation




    3.1  See 4.1, 4.2, 4.3, 4.4 under Modified Winkler Method.








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.




         4.2.1  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.  Broad




                variations in the kinds and concentrations of salts in




                samples can make the use of a membrane  probe difficult.
                                66

-------
                                                  (DO -  Probe Method)


                                                               /
     4.2.2  The thallium probe requires  the presence of  salts in

            concentrations which provide a minimum conductivity of

            approximately 200 micromhos.

4.3  Reactive compounds can interfere with the output or the per-

     formance of dissolved oxygen probes.

     4.3.1  Reactive gases which pass through the membrane of

            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 eventu-

            ally 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.

     4.3.2  Sulfur compounds (hydrogen sulfide, sulfur dioxide and

            mercaptans, for example)  cause interfering outputs from

            the thallium probe.  Halogens  do not interfere with the

            thallium probe.



4.4  At low dissolved oxygen concentrations, pH variation below

     pH 5 and above  pH 9 interfere with  the performance  of the
                            67

-------
                                                      (DO - Probe Method)








         thallium probe (approximately 0.05 mg/1 DO per pH unit).




         The performance of membrane  probes is not affected by pH




         changes.




    4.5  Dissolved oxygen probes are temperature sensitive, and tem-




         perature compensation is normally provided by the manufac-




         turer.  The thallium probe has a temperature coefficient of




         1.9 m/C.  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 Delta Scientific, Model 85.








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.
                                  68

-------
                            FLUORIDE


                  (Automated Coraplexone Method)





1.  Scope and Application


    1.1  This method is applicable to surface waters, domestic and


         industrial wastes, and saline waters.  The applicable range


         of the method is 0.05 to 1.5 mg F/l.  Twelve samples per


         hour can be analyzed.





2.  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.





3.  Sample Handling and Preservation


    3.1  No special requirements.





4.  Interferences


    4.1  Method is free from most anionic and cationic interferences,


         except aluminum, which forms an extremely stable fluoro com-

                    -2
         pound, AIFg  .  This is overcome by treatment with 8-hydroxy


         quinoline to complex the aluminum and by subsequent extraction


         with chloroform.
                                69

-------
                                                             (Fluoride)









5.   Apparatus



    5.1  Technicon AutoAnalyzer Unit consisting of:




         5.1.1  Sampler I.



         5.1.2  Manifold.




         5.1.3  Proportioning pump.




         5.1.4  Continuous filter.




         5.1.5  Colorimeter equipped with 15 mm tabular




                flow cell and 650 my filters.




         5.1.6  Recorder equipped with range expander.




6.   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-hydroxyquinoline solution:  Dissolve 6 g of 8-




         hydroxyquinoline in 34 ml of cone, acetic acid, and dilute




         to 1 liter.




    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.  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 of 2 N




         hydrochloric acid and mix with above solution.  Dilute to 1 liter.
                                   70

-------
                                                              (Fluoride)



    6.7  Stock Solution:   Dissolve 2.210 g of sodium fluoride in 100

         ml of distilled  water and dilute to 1 liter.   1 ml = 1.0 mg F.

    6.8  Standard Solution:   Dilute 10.0 ml of stock solution to 1

         liter.   1 ml  = 0.01 mg F.

         6.8.1  Using  standard solution, prepare the following stan-

                dards  in  100-ml volumetric flasks:

                  mg F/l       ml Standard Solution/100 ml

                   0.05                   0.5
                   0.10                   1.0
                   0.20                   2.0
                   0.40                   4.0
                   0.60                   6.0
                   0.80                   8.0
                   1.00                  10.0
                   1.20                  12.0
                   1.50                  15.0


7.   Procedure

    7.1  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 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.
                                   71

-------
                                                          (Fluoride)








8.  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.








9.  Precision and Accuracy




    9.1  In a single  laboratory, using surface water samples at con-




         centrations  of  0.06, 0.15, 0.55, and 1.08 mg F/l, the stan-




         dard deviation  was  0.018  (AQC Laboratory).




    9.2  In a single  laboratory, using surface water samples at concen-




         trations of  0.14  and 1.25 mg F/l recoveries were 89% and 102%,




         respectively (AQC Laboratory).








                              References
1.  R. Greenhaigh  and  J.  P.  Riley,  "The Determination of Fluorides in




    Natural Waters, with  Particular Reference  to Sea Water."  Anal.




    Chim. Acta,  25_, 179  (1961).




2.  K. M. Chan and J.  P.  Riley,   "The Automatic Determination of




    Fluoride in  Sea Water and  Other Natural Waters."  Anal. Chim. Acta,




    35,  365 (1966).
                                 72

-------
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-------
                             FLUORIDE



                  (Specific Ion Electrode Method)







1.   Scope and Application



    1.1  This method is applicable to the measurement of fluoride in



         finished waters, natural waters, brines,  and industrial waste



         waters and the need for distillation of the sample is elimi-



         nated.



    1.2  Concentrations of fluoride from 0.1 up to 1000 mg/liter may



         be measured.







2.   Summary of Method



    2.1  The fluoride is determined potentiometrically using a specific



         ion fluoride electrode in conjunction with a standard single



         junction sleeve-type reference electrode and a pH meter having



         an expanded millivolt scale or a specific ion meter having a



         direct concentration scale for fluoride.



    2.2  The fluoride electrode consists of a lazer-type doped lanthanum



         fluoride crystal across which a potential is developed by



         fluoride ions.  The cell may be represented by Ag/Ag Cl, Cl



         (0.3), F" (0.001) LaF / test solution/SCE/.
                              o






3.   Interferences



    3.1  Extremes of pH interfere; sample pH should be between 5 and 9.



         Polyvalent cations of Si  , Fe   and Al   interfere by forming



         complexes with fluoride.  The degree of interference depends
                                  75

-------
                                                          (Fluoride)



         upon the concentration of the complexing cations, the con-

         centration 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.



4.   Sample Handling and Preservation

    4.1  No special requirements.



5.   Apparatus

    5.1  Electrometer, (pH meter) with expanded mv scale or a specific

         ion meter such as the Orion 400 Series.

    5.2  Fluoride Ion Activity Electrode, such as Orion No. 94-09.

    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.



6.   Reagents

    6.1  Buffer solution, pH 5.0-5.5.  To approximately 500 ml of

         distilled water in a one-liter beaker add 57 ml of glacial

         acetic acid, 58 g of sodium chloride and 2 g of CDTA   
^ 'CDTA is the abbreviated designation of 1,2-cyclohexylene dinitrilo
   tetraacetic acid, produced by Mathieson, Coleman  Bell, Cat. No.
   P8661.
                                76

-------
                                                            (Fluoride)



         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 dis-

         tilled 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.



         Note - CDTA replaces citric acid used in the original buffer

         formula.  It is a strong chelating agent and more effectively

         ties up aluminum than the  original citric acid.

    6.2  Sodium fluoride, stock solution (1.0 ml = 0.01  mg F),



7.   Calibration

    7.1  Prepare a series of standards using the fluoride stock solu-

         tion (1 ml = 0.01 mg F) in the range of 0 to 2.00 mg/liter

         by diluting appropriate volumes to 50 ml.   The  following

         series may be used:

           Milliliters of Stock        Concentration when Diluted
           (1.0 ml = 0.01 mg/F)           to 50 ml, mg F/liter

                  0.00                            0.00
                  1.00                            0.20
                  2.00                            0.40
                  3.00                            0.60
                  4.00                            0.80
                  5.00                            1.00
                  6.00                            1.20
                  8.00                            1.60
                 10.00                            2.00
                                77

-------
                                                          (Fluoride)








    7.2  Calibration of Electrometer:   Immerse the electrodes in each




         stock solution starting with the lowest concentration and




         measure the developed potential while mixing.   The electrodes




         must remain in the solution for at least three minutes or




         until the reading has stabilized.  Using semilogarithmic




         graph paper, plot the concentration of fluoride in mg/liter




         on the log axis vs. the electrode potential developed in the




         standard on the linear axis, starting with the lowest concen-




         tration at the bottom of the scale.




    7.3  Calibration of a specific ion meter:  Follow the directions




         of the manufacturer for the operation of the instrument.








8.   Procedure




    8.1  Place 50.0 ml of sample and 50.0 ml of buffer 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 ml/liter F, it may




         require as  long as five minutes  to reach a stable meter reading;




         higher concentrations stabilize more quickly.   If a pH meter




         is used, record the potential measurement for each unknown




         sample and  convert the potential reading to the fluoride ion




         concentration of the unknown using the standard curve.  If a




         specific ion meter is used, read the fluoride level in the



         unknown sample directly in mg/1  on the fluoride scale.
                                  78

-------
                                                          (Fluoride)
                          \


9.  Precision and Accuracy

    9.1  A synthetic sample prepared by the Analytical Reference Ser-

         vice, PHS, containing 0.85 mg/1 fluoride and no interferences

         was analyzed by 111 different analysts;  a mean of 0.84 mg/1

         with a standard deviation of 0.030 was  obtained.

    9.2  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.
                                79

-------
                       HARDNESS,  TOTAL


               (Automated Eriochrome BT Method)





1.   Scope and Application


    1.1  This automated method is applicable to  surface and saline


         waters.   The applicable  range is 10 to  400 mg/1 as CaCO .
                                                                o

         Approximately 12 samples per hour can be analyzed.





2.   Summary of Method


    2.1  The disodium magnesium EDTA exchanges magnesium on an equi-


         valent basis for any calcium and/or other cations to form a


         more stable EDTA chelate than magnesium.  The free magnesium


         reacts with Eriochrome Black T at a pH  of 10 to give a red-


         violet complex.   Thus, by measuring only magnesium concen-


         tration in the final reaction stream, an accurate measurement


         of total hardness is possible.





3.   Sample Handling and Preservation


    3.1  No special requirements.





4.   Interferences


    4.1  No significant interferences.





5.   Apparatus


    5.1  Technicon AutoAnalyzer consisting of:


         5.1.1  Sampler I.


         5.1.2  Continuous Filter.
                                81

-------
                                                     (Hardness, Total)



         5.1.3  Manifold.

         5.1.4  Proportioning Pump.

         5.1.5  Colorimeter equipped with 15 mm tubular flow cell

                and 520 my filters.

         5.1.6  Recorder equipped with range expander.



6.  Reagents

    6.1  Buffer:  Dissolve 67.6 g NH4C1 in 572 ml of NhLOH and dilute

         to 1 liter.

    6.2  Eriochrome Black T (or Calmagite):  Dissolve 0.25 g in 500 ml

         of distilled water by stirring approximately 30 minutes on a

         magnetic stirrer.  Filter.

    6.3  Magnesium EDTA:  Dissolve 0.2 g of MgEDTA in 1 liter of dis-

         tilled water.

    6.4  Stock Solution:  Weigh 1.0 g of calcium carbonate (pre-dried

         at 105C) into 500 ml Erlenmeyer flask; add 1:1 HC1 until all

         CaCOj has dissolved.  Add 200 ml of distilled water and boil

         for a few minutes.  Cool, add a few drops of methyl red indi-

         cator, and adjust to the orange color with 3N NH.OH and dilute

         to 1 liter.  1.0 ml = 1.0 mg CaC03.

         6.4.1  Dilute each of the following volumes of stock solutions

                to 250 ml for appropriate standards:

                     Stock Solution, ml        CaC03, mg/1

                             2.5                   10.0
                             5.0                   20.0
                            10.0                   40.0
                            15.0                   60.0
                            25.0                  100
                            35.0                  140
                            50.0                  200
                            75.0                  300
                           100.0                  400

                                82

-------
                                                   (Hardness,  Total)

7.   Procedure
    7.1  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 in
         Sampler and set sample timing at 2.5 minutes.
    7.4  Arrange working 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.

8.   Calculation
    8.1  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.
    o
9.   Precision and Accuracy
    9.1  In a single laboratory (AQC), using surface water samples at
         concentrations of 19, 120, 385, and 366 mg/1 as CaCO.,, the
         standard deviations were 1.5, 1.5, 4.5, and 5.0, respec-
         tively
    9.2  In a single laboratory (AQC), using surface water samples at
         concentrations, of 39 and 296 mg/1 as CaCOj, recoveries were
         89% and 93%, respectively.
                                83

-------
                                                   (Hardness, Total)








                           References




1.  Technicon AutoAnalyzer Methodology, Bulletin No.  2, Technicon




    Controls, Inc., Chauncey, New York (July 1960).




2.  Standard Methods, 12th Edition, p 147, American Public Health




    Association, New York, N.Y.  (1965).
                                 84

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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 surface waters,




         domestic and industrial wastes, and saline waters.








    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, will provide the reader




         with some indication of the concentration ranges deter-




         minable.   In the majority of instances  the concentration




         range shown in the table may be extended much lower with




         scale expansion and conversely extended upwards by using




         a less sensitive wavelength.   Sensitivity may also be ex-




         tended through concentration of the sample, or through




         solvent extraction techniques.  Following are detection




         limits, sensitivities, and the optimum  concentration




         ranges achieved directly on the sample  using the




         Instrumentation Laboratories, Model IL-153 without scale




         expansion (Pos 2.5).
                                87

-------
                                                             (Metals)
                                                           Optimum
                                                        Concentration
Metal
Aluminum
Arsenic
Cadmium
Calcium
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Potassium
Silver
Sodium
Zinc
Detection Limit
mg/1
0.1
0.25
0.001
0.003
0.01
0.005
0.004
0.01
0.0005
0.005
0.005
0.01
0.001
0.005
Sensitivity
mg/1
0.4
0.5
0.004
0.07
0.02
0.04
0.006
0.06
0.005
0.04
0.01
0.05
0.003
0.02
Range
mg/1
10
10
0.1
1
1
0.1
0.1
1
0.01 -
0.1
0.01 -
0.1
1
0.1

1000
100
2
200
200
10
20
10
2
20
2
20
200
2
2.  Summary of Method

    2.1  Atomic absorption spectroscopy is similar to flame emission

         photometry in that a sample is aspirated into a flame and

         atomized.  Flame photometry, however, measures the amount of

         light emitted, whereas, in atomic absorption spectrophotometry

         a light beam is directed through the flame into a monochromator,

         and onto a detector that measures the amount of light absorbed.

         In many instances absorption is more sensitive because it de-

         pends upon the presence of free unexcited atoms and generally

         the ratio of unexcited to excited atoms at a given moment is

         very high.  Since the wavelength of the light beam is character-

         istic 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.
                               88

-------
                                                                 Metals
    2.2   Although  methods have been  reported  for  the  analysis  of solids




          by atomic absorption spectroscopy  the  technique  generally  is




          limited to metals  in solution or solubilized through  some  form




          of sample processing.   Thus it is  a  relatively simple matter  to




          determine metals in the soluble fraction by  aspirating a




          filtered  portion of the water sample.




    2.21  In those  instances where complete  characterization of a sample




          is desired, the suspended material must  also be  analyzed.   This




          may be accomplished by  filtration  and  acid digestion  of the sus-




          pended material.   Metalic constituents in this acid digest are




          subsequently determined and the sum  of the dissolved  plus  sus-




          pended concentrations will  then provide  the  total  concentrations




          present




    2.22  The sample may also be  treated with  acid before  filtration to




          measure what may be termed  "extractable" concentrations.








3.   Definition Of Terms




    3.1   Sensitivity:  is the concentration in  milligrams of metal  per




          liter that produces an  absorption  of 1%.




    3.2   Detection Limit:   is defined as the  concentration that produces




          absorption equivalent to twice the magnitude of  the fluctuation




          in the background  (zero absorption).                 




    3.3   Dissolved:  those  constituents which will pass through a 0.45 y




          membrane filter.




    3.4   Suspended:  those  constituents which are retained by  a 0.45 y




          membrane filter.
                                 89

-------
                                                               (Metals)








    3.5   Total:  concentration is the sum of the concentrations  in




          the dissolved and suspended fraction.




    3.6   Extractable:  the extractable fraction is the dissolved




          concentrations plus that quantity adsorbed on the surface of




          the silt particles that is soluble in hot dilute mineral




          acids.








4.  Sample Handling and Preservation




    4.1   For the determination of trace metals, contamination and




          loss are of prime concern.  Dust in the laboratory environ-




          ment, 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 traee 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 should be thoroughly washed




          with detergent and tap water; rinsed with chromic acid, tap




          water, nitric acid, tap water and finally distilled water in




          that order.  After collection of the sample the analyst must



          decide on the type of desired data, ie., dissolved, suspended,




          total or extractable, before proceeding with the sample




          handling.
                                 90

-------
                                                         (Metals)








4.11  For the determination of soluble constituents  the sample




      should be filtered through a 0.45 y membrane filter as  soon




      as practicable after collection.  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 nitric acid  (3 ml per liter).  Normally this amount




      of acid will lower the pH to 2 or 3 and should be sufficient to




      preserve the sample indefinitely.  Analyses performed on a sam-




      ple so treated shall be  reported as "dissolved" concentrations.




4.12  For the determination of suspended metals a representative




      volume of sample should  be filtered through a  0.45 y




      membrane filter.  When considerable sediment is present, as




      little as 100 ml of a well shaken sample is filtered.








      Record the volume filtered and transfer the membrane filter




      containing the sediment  to a 250 ml Griffin beaker and add




      3 ml distilled HNO,.  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 ar.d  digest the




      material.  When the acid has evaporated, cool  the beaker




      and watch glass and add another 3 ml of distilled HNO,.








      Cover and continue heating until the digestion is complete,




      generally indicated by a light colored residue.  Add dis-




      tilled 1:1 HC1 (2 ml) to the dry residue and again warm the
                            91

-------
                                                         (Metals)







      beaker gently to dissolve the material.  Wash down the



      watch glass and beaker walls with distilled water and



      filter the sample to remove silicates and other insoluble



      material that would clog the atomizer.  Adjust the volume



      to some predetermined value based on the expected concen-



      trations of trace 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".  STORET parameter num-



      bers for reporting this type of data are currently not



      available.



4.13  To determine metals soluble in diluted hot HC1 - HNO,,
                                                          o


      acidify the entire sample at the time of collection with



      redistilled HNO,, 5 ml/1.  At the time of analysis the
                     o


      sample is mixed and a 100-ml aliquot transferred to a beaker



      or flask.  Five ml of redistilled hydrochloric acid is added



      and the sample heated for 15 minutes on a steam bath or hot



      plate.  After this digestion period the sample is filtered



      and the volume adjusted to 100 ml.  The sample is then ready



      for analysis.








      The data so obtained are significant in terms of "total"



      metals in the sample, with the reservation that something



      less than "total" is actually measured.  Concentrations of



      metal found, especially in heavily silted samples, will be
                            92

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                                                             (Metals)








          substantially higher than  data obtained on  only  the  soluble




          fraction.   STORE! parameter numbers  for the storage  of this




          type data are not available.








5.   Interferences




    5.1   The most troublesome type  of interference  in atomic  absorption




          spectrophotometry is usually termed  "chemical" and results




          from lack of absorption of atoms  bound in  molecular  combina-




          tion 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 inter-




          ference  in the magnesium determination. Similarly,  silica




          interference in the determination of manganese can be elimi-




          nated by the addition of calcium.




    5.11  Chemical interferences may also be eliminated by separating




          the metal from the interfering material.  While  complexing




          agents are usually employed to increase the sensitivity of




          the analysis they may also be used to eliminate  or reduce




          interferences.








6.  Apparatus




    6.1  Atomic absorption spectrophotometer:   Instrumentation Laboratory,




         Model IL-153 or equivalent.  A satisfactory instrument will have
                                  93

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                                                              (Metals)








          an energy source, an atomizer burner system, a monochrometer,




          and a detector.




    6.2   Burner:  A Boling burner is recommended for most aqueous




          solutions.  A premix burner is used for organic solvents.




          For certain elements the nitrous oxide burner is preferred.




    6.3   Volumetric flasks; 200 ml, for extraction with organic




          solvents.




    6.4   Glassware:  All glassware, including sample bottles,  should




          be washed with detergent, rinsed with tap water, chromic




          acid, tap water, 1:1 nitric acid, tap water and distilled




          water in that order.




    6.5   Borosilicate glass distillation apparatus.








7.   Reagents




    7.1   Deionized distilled water:  Prepare by passing distilled




          water through a mixed bed of cation and anion exchange




          resins.  Use deionized distilled water for the preparation




          of all reagents, calibration standards, and as dilution




          water.




    7.2   Nitric acid (cone):  Distill reagent grade nitric acid in  a




          borosilicate glass distillation apparatus.  Prepared a 1:1




          dilution with deionized distilled water.




    7.3   Hydrochloric acid  (1:1):  Prepare a 1:1 solution of reagent




          grade hydrochloric acid and distilled water.  Distill this




          mixture  from a borosilicate glass distillation apparatus.
                                  94

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                                                      (Metals)








    7.4   Stock metal solutions:   Prepare as directed in 8.1 and




          under the individual metal procedures.




    7.5   Standard metal solutions:  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.




    7.7   Special reagents for the extraction procedure




          a.  Ammonium pyrrolidine dithiocarbamate solution (APDC):




              Dissolve Ig APDC in 100 ml of deionized distilled water.




              Prepare fresh before use.




          b.  Bromphenol blue indicator solution:




              Dissolve 0.Ig bromphenol blue in 100 ml 50% ethanol.




          c.  Hydrochloric acid,  0.5N:




              Mix 25 ml cone. HC1 with deionized distilled water and




              dilute to 1 liter.




          d.  Methyl isobutyl ketone (MIBK):
Ammonium pyrrolidine dithiocarbamate (APDC) may be obtained commercially




from Fisher Scientific Company (Cat. No.  A-182), K and K Labs Inc.  or




Eastman Kodak.
                                95

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                                                             (Metals)








          e.  Sodium hydroxide, 2.5N:




              Dissolve 10 g NaOH in deionized distilled water and




              dilute to 100 ml.








8.  Preparation of Standards and Calibration




    8.1   Stock solutions are prepared from high purity metals,




          oxides or nonhygroscopic reagent grade salts  using redis-




          tilled nitric or hydrochloric acids.   Sulfuric or phosphoric




          acids should be avoided as they produce an adverse effect  on




          many elements.   The stock solutions are prepared at concen-




          trations of 1000 mg/1.




    8.2   Standard solutions are prepared by diluting the stock  metal




          solutions at the time of analysis.  For best  results,  cali-




          bration standards should be prepared fresh each time an




          analysis is to be made and discarded after use.  Prepare a




          blank and calibration standards in graduated  amounts in the




          appropriate range.  As the filtered samples are preserved




          with redistilled nitric acid (3 ml (1:1) per  liter) the acid




          strength of the calibration standards should  be similarly




          adjusted.  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.




    8.3   For those instruments which do not read out directly in




          concentration a calibration curve is prepared to cover the
                                 96

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                                                             (Metals)

                                                j
         appropriate concentration  range.   Usually,  this  means  the

         preparation of standards which  produce  an absorption of 0

         to 80 percent.   The  correct  method for  plotting  data derived

         from an atomic absorption  instrument  equipped with  a linear

         readout system is  to convert percent  absorption  to  absorbance

         and plot the absorbance  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

         in that portion of the  curve.


9.  General Procedure for Analysis  by Atomic Absorption

    9.1  Differences between  the  models  of satisfactory atomic  absorp-

         tion 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

         correct hollow cathode  lamp  for the analysis, the lamp should

         be allowedto warm  up for a minimum of 15 minutes.   During

         this period, align the  instrument, position the  monochromator

         at the correct wavelength, select the proper monochromator

         slit width, adjust the  hollow cathode current according to

         the manufacturer's recommendation, light the flame  and regulate
                                97

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                                                         ('Metals)









      the flow of fuel and oxidant, adjust the burner for maximum




      percent absorption and stability and balance the photometer.




      Run a series of standards of the element under analysis and




      construct working curves 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.  For best results run standards each time




      a sample or series of samples are run.




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, cer-




      tain of the metals may be chelated and extracted with organic




      solvents.  Ammonium pyrrolidine dithiocarbamate (APDC) is




      widely used for this purpose and is particularly useful for




      zinc, cadmium, iron, manganese, copper, silver, lead and




      chromium   .  The most frequently used organic solvent for




      APDC is methyl isobutyl ketone (MIBK).  Apart from the fact




      that the solvent should extract the chelate, it should burn




      and provide a stable flame.  In addition, the physical prop-




      erties of  the solvent such as viscosity, surface tension,




      boiling point, and mutual solubility  in an aqueous medium




      must be taken into account.  It should not produce toxic




      products during combustion or give a  high background in the



      flame.
                              98

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                                                          (Metals)








9.21  Extraction Procedure with APDC



      a.   Pipet a volume of sample  (100  ml  max.)  into a 200 ml




          volumetric flask and adjust  the volume  to 100 ml  with




          deionized distilled water.




      b.   Prepare a blank and sufficient standards  in the same




          manner and adjust the volume of each to approximately




          100 ml with deionized distilled water.




      c.   Add 2 drops of bromphenol blue indicator  solution.




      d.   Adjust the pH of the sample  by dropwise addition  of




          2.5N NaOH until a blue color persists.  Add 0.3N  HC1




          dropwise until the blue color  just disappears in  both




          standards and samples. Then add  2.0 ml of 0.3N HC1 in




          excess.




      e.   Add 2.5 ml fresh APDC solution and mix.




      f.   Add 10.0 ml MIBK and shake vigorously for 1 minute.




      g.   Allow the layers to separate and  add deionized distilled




          water until the ketone layer is completely in the neck




          of the flask.




      h.   Aspirate the ketone layer and  record the  scale readings




          for each standard and sample against the  prepared blank.




          Repeat and average the duplicate  results.   Plot a cali-




          bration curve in pg metal vs.  absorbance.




      Note:




      When aspirating organic solvents the  fuel-to-air ratio should




      be  reduced as the burning of the organic solvent contributes




      to  the fuel supply.   When adjusting the fuel-to-air ratio of
                             99

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                                                              (Metals)


          the gas mixture at the burner, begin with the settings
          recommended by the manufacturer.  Gradually reduce the fuel
          flow while the organic solvent is being aspirated until the
          flame is as blue as possible.  Care should be taken that the
          flame does not lift off the burner producing an undesirable
          luminescent flame.


10.  Calculation
     10.1 Direct determination:  Read the metal value in mg/1 from the
          calibration curve or directly from the readout system of the
          instrument.
            mg/1 metal in sample = (mg/1 of metal in the aliquot) x D
            where D = ml of aliquot + ml of deionized distilled water
                                      ml of aliquot
     10.2 Extracted samples:  Read the metal value in Ug from the extracted
          calibration curve or from the readout system of the instrument.
            mg/1 metal in sample = yg metal in aliquot
                                      ml of aliquot


11.  Precision and Accuracy
     11.1 Three synthetic unknown samples containing varying concen-
          trations of cadmium, chromium, copper, iron, lead, magnesium,
          manganese, silver, and zinc were analyzed in 59 laboratories
          with the results indicated in Table 2.  (Analytical Reference
          Service PHS)
                                100

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                                                               (Metals)
                               Table 2
       Precision and Accuracy Data for Atomic Absorption Methods
      Metal
    Metal
Concentration,
     Hg/1
Relative
Error,
percent
Relative
Standard
Deviation,
 percent
Direct determination
Cadmium
Chromium
Copper
Iron
Magnesium
Manganese
Silver
Zinc
Extracted samples
Cadmium
Lead
      50
      50
    1000
     300
     200
      50
      50
     500

      10
      50
 8.15
 2.29
 3.42
 0.64
 6.30
 6.00
10.57
 0.41

 3.03
19.00
 21.62
 26.44
 11.23
 16.53
 10.49
 13.50
 17.47
  8.15

 72'. 77
 23.46
                                 101

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                                                              (Metals)






                   Aluminum - Standard Conditions








Optimum Concentration Range   10-1000 mg/1 using the 3092 A line




Sensitivity  0.4 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 concen-




         trated HC1 to the metal in a covered beaker and warm




         gently.  When solution is complete, transfer quantitatively




         to a 1 liter volumetric flask and make up to volume with




         distilled water.  One ml equals 1 mg Al.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% nitric acid in all calibration




         standards.




Instrumental Parameters  (General)




     1.  Aluminum hollow cathode lamp




     2.  Wavelength:  3092 A




     3.  Type of burner:  Nitrous oxide




     4.  Fuel:  Acetylene




     5.  Oxidant:  Nitrous oxide




     6.  Type of flame:  Fuel rich




     7.  Photomultiplier tube:  IP-28
                                102

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                                                                (Metals)
Notes




     1.  The following lines may also be used




         3082 A Relative Sensitivity  1




         3962 A Relative Sensitivity  2




         3944 A Relative Sensitivity  2.5
                                 103

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                                                               (Metals)
                   Arsenic - Standard Conditions








Optimum Concentration Range  10-100 mg/1 using the 1937 A line




Sensitivity  0.5 mg/1




Detection Limit  0.25 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Dissolve 1.320 grams of arsenic trioxide




         (AsJD,, analytical reagent grade) in a small quantity of




         distilled water in which a pellet of NaOH has previously




         been dissolved.  When solution is complete acidify with




         HC1 and make up to 1 liter with distilled water.  One ml




         equals 1 mg As (1000 mg/1.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Do not




         acidify with nitric acid.




Instrumental Parameters (General)




     1.  Arsenic hollow cathode lamp




     2.  Wavelength:  1937 A




     3.  Type of burner:  Doling




     4.  Fuel:  Hydrogen




     5.  Oxidant:  Argon




     6.  Type of flame:  Fuel rich




     7.  Photomultiplier tube:  R-106
                                 104

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                                                              (Metals)
Notes




     1.  The R-106 photomultiplier tube is more sensitive to UV




         light and therefore is suggested in place of the IP-28




         phototube.




     2.  The presence of nitric acid causes interference in the




         argon-hydrogen system, therefore a separate sample pre-




         served with HC1 should be analyzed.




     3.  Samples high in total salt content (above 1%) will




         produce an apparent absorption at the 1937 A arsenic




         line even when the element is absent.  It is necessary,




         therefore, to correct absorption readings at low ab-




         sorptions by subtracting the signal obtained at a




         neighboring, nonabsorbing line.




     4.  The high-solids burner is reported to give lower




         detection limits.
                                 105

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                                                              (Metals)
                     Cadmium -  Standard Conditions








Optimum Concentration Range  0.1-1 mg/1 using the 2288 A line




Sensitivity  0.004 mg/1




Detection Limit  0.001 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.142 gram of cadmium




         oxide (CdO, analytical reagent grade) and dissolve in




         5 ml redistilled HNO  .  Dilute to 1 liter with distilled




         water.  One ml equals 1 mg Cd.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% nitric acid in all calibration




         standards.




Instrumental Parameters (General)




     1.  Cadmium hollow cathode lamp




     2.  Wavelength:  2288 A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28
                                 106

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                                                             (Metals)







                     Calcium - Standard Conditions







Optimum Concentration Range  1.0-200 mg/1 using the 4227 A line



Sensitivity  0.07 mg/1



Detection Limit  0.003 mg/1



Preparation of Standard Solution



     1.  Stock Solution:   Suspend 1.250 grams of CaCO, (analytical



         reagent grade),  dried at 180 C for 1 hour before weighing,



         in distilled water and dissolve cautiously with a minimum



         of dilute HC1.  Dilute to 1000 ml with distilled water.



         One ml equals 0.5 mg of Ca (500 mg/1).



     2.  Lanthaum chloride solution:  Dissolve 29 g of La?0 ,  slowly
                                                         ^ -J


         and in small portions, in 250 ml concentrated HC1.  (Caution!



         Reaction is violent) and dilute to 500 ml with distilled water.



     3.  Prepare dilutions of the stock calcium solution to be used as



         calibration standards at the time of analysis.  To each  cali-



         bration standard solution, add 1.0 ml of Lad, solution  for



         each 10 ml of volume of working standard, ie., 20 ml  working



         standard + 2 ml  Lad- = 22 ml.



Instrumental Parameters (General)



     1.  Calcium hollow cathode lamp



     2.  Wavelength:  4227 A



     3.  Type of burner:   Boling



     4.  Fuel:  Acetylene



     5.  Oxidant:  Air



     6.  Type of flame:  Reducing



     7.  Photomultiplier tube:  IP-28
                              107

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                                                              (Metals)








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 inter-




         ferences,  lonization interferences should be controlled




         by adding a large amount of alkali to the samples and




         standards.  The analysis appears to be free from chemical




         supressions in the nitrous oxide - acetylene flame.




     4.  The 2399 A line may also be used.  This line has a sensitivity




         of 20 mg/1.
                                108

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                                                              (Metals)
                   Chromium - Standard Conditions








Optimum Concentration Range  1.0-200 mg/1 using the 3579 A line




Sensitivity  0.02 mg/1




Detection Limit  0.01 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Dissolve 1.923 gram of chromium trioxide




         (CrO_, reagent grade) in distilled water.  When solution




         is complete acidify with redistilled HNO, and dilute to 1




         liter with distilled water.  One ml equals 1 mg chromium.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% nitric acid in all calibration




         standards.




Instrumental Parameters (General)




     1.  Chromium hollow cathode lamp




     2.  Wavelength:  3579 A




     3.  Type of burner:  Doling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air



     6.  Type of flame:  Slightly fuel rich




     7.  Photomultiplier tube:  IP-28
                                 109

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                                                               (Metals)








Notes




     1.  The following wavelengths may also be used




         3605 A Relative Sensitivity  1.2




         3593 A Relative Sensitivity  1.4




         4254 A Relative Sensitivity  2




         4274 A Relative Sensitivity  3




         4289 A Relative Sensitivity  4




     2.  The determination of chromium requires a rich acetylene




         flame.  The absorption is very sensitive to the fuel-to-




         air ratio.




     3.  The absorption of chromium is suppressed by iron and nickel.




         If the analysis is performed in a lean flame the inter-




         ference can be lessened but the sensitivity will also be




         reduced.  The interference does not exist in a nitrous oxide -




         acetylene flame.
                                 110

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                                                              (Metals)








                     Copper - Standard Conditions








Optimum Concentration Range  0.1-10 mg/1 using the 3247 A line




Sensitivity  0.04 mg/1




Detection Limit  0.005 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.00 gram of electrolytic




         copper (analytical reagent grade).   Dissolve in 5 ml re-




         distilled HNO, and make up to 1 liter with 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.  Maintain




         an acid strength  of 0.15% nitric acid in all calibration



         standards.




Instrumental Parameters (General)




     1.  Copper hollow cathode lamp




     2.  Wavelength:  3247  A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame: Oxidizing




     7.  Photomultiplier tube:   IP-28
                                 111

-------
                                                              (Metals)
Notes




     1.  For copper concentrations below 0.05 mg/1, the extraction




         procedure is suggested.




     2.  Copper atoms are distributed over a wider area in laminar




         flow-flames than that normally found.  Consequently, the




         burner parameters are not as critical as for most other




         elemental determinations.




     3.  Because of the spectral intensity of the 3247 A line, the




         P.M. tube may become saturated.  If this situation occurs




         the current should be decreased.




     4.  Numerous absorption lines are available for the deter-




         mination of copper.  By selecting a suitable absorption




         wavelength, copper samples may be analyzed over a very




         wide range of concentration.  The following lines may be




         used.




              3264 A Relative Sensitivity  2




              2178 A Relative Sensitivity  4




              2165 A Relative Sensitivity  7




              2181 A Relative Sensitivity  9




              2225 A Relative Sensitivity 20




              2024 A Relative Sensitivity 20




              2492 A Relative Sensitivity 90
                                 112

-------
                                                               (Metals)
                     Iron - Standard Conditions








Optimum Concentration Range  0.1-20 mg/1 using the 2483 A line




Sensitivity  0.006 mg/1




Detection Limit  0.004 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.000 gram of pure iron




         wire (analytical reagent grade) and dissolve in 5 ml re-




         distilled HNO,, warming if necessary.  When solution is




         complete make up to 1 liter with distilled water.  One ml




         equals 1 mg Fe.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% nitric acid in all calibration




         standards.




Instrumental Parameters (General)




     1.  Iron hollow cathode lamp




     2.  Wavelength:  2483 A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28
                                 113

-------
                                                              (Metals)
Notes




     1.  The following  lines may also be used




         2488 A Relative Sensitivity  2




         2522 A Relative Sensitivity  2




         2719 A Relative Sensitivity  4




         3021 A Relative Sensitivity  5




         2527 A Relative Sensitivity  6




         2721 A Relative Sensitivity  9




         3720 A Relative Sensitivity 10




         2967 A Relative Sensitivity 12




         3860 A Relative Sensitivity 20




         3441 A Relative Sensitivity 30




     2.  Absorption is strongly dependent upon the lamp current.




     3.  Better signal-to-noise can be obtained from a neon-filled




         hollow cathode lamp than from an argon-filled lamp.
                                  114

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                                                              (Metals)









                     Lead - Standard Conditions








Optimum Concentration Range  1-10 mg/1 using the 2170 A line




Sensitivity  0.06 mg/1




Detection Limit  0.01 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.599 gram of analytical




         reagent grade lead nitrate (Pb(NO,)_,) and dissolve in re-




         distilled water.  When solution is complete acidify with




         10 ml redistilled HN03 and dilute to 1 liter with distilled




         water.  One ml equals 1 mg Pb (1000 mg/1).




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.   Maintain




         an acid strength of 0.15% nitric acid in all calibration



         standards.




Instrumental Parameters (General)




     1.  Lead hollow cathode lamp




     2.  Wavelength:  2170




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidaht.c.  Air




     6.  Type of flame:  Slightly oxidizing




     7.  Photomultiplier tube:  IP-28
                                  115

-------
                                                             (Metals)








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 in




         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.  Better analytical results with the 2170 A line may be




         obtained by using a R-106 photomultiplier tube which is




         more sensitive to UV light.




     3.  For lead concentrations below 0.2 mg/1, the extraction




         procedure is suggested.




     4.  The following lines may also be used




         2833 A Relative Sensitivity   2




         2614 A Relative Sensitivity 500




         3683 A Relative Sensitivity 900
                              116

-------
                                                              (Metals)
                   Magnesium - Standard Conditions







Optimum Concentration Range  0.01-2 mg/1 using the 2852 A line



Sensitivity  0.005 mg/1



Detection Limit  0.0005 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 HNO
                                                               O


         and dilute to 1 liter with distilled water.   One ml equals



         0.50 Mg.



     2.  Lanthanum chloride solution:   Dissolve 29 g of La_0 ,
                                                          ^ _)


         slowly and in small portions  in 250 ml concentrated HC1.



         (Caution!  Reaction is violent) and dilute to 500 ml with



         distilled water.



     3.  Prepare dilutions of the stock magnesium solution to be



         used as calibration standards at the time of analysis.



         To each calibration standard solution, add 1.0 ml of



         LaCl_ solution for each 10 ml of volume of working stan-
             O


         dard, ie., 20 ml  working standard + 2 ml LaCl_ = 22 ml.



Instrumental Parameters (General)



     1.  Magnesium hollow  cathode lamp



     2.  Wavelength:  2852 A



     3.  Type of burner:  Boling



     4.  Fuel:  Acetylene



     5.  Oxidant:  Air



     6.  Type of flame:  Reducing



     7.  Photomultiplier tube:  IP-28
                                117

-------
                                                              (Metals)
Notes




     1.  Analytical sensitivity decreases with increased lamp




         current.




     2.  The interference caused by aluminum at concentrations




         greater than 2 mg/1 is masked by addition of lanthanum.




         Since low magnesium values result if the pH of the sam-




         ples is above 7, both standards and samples are prepared




         in dilute hydrochloric acid.  Sodium, potassium and




         calcium cause no interference at concentrations less




         than 400 mg/1.




     3.  Because of the spectral intensity of the 2852 line,




         the P.M. tube may become saturated.  If this situation




         occurs, the current should be decreased.




     4.  The following lines may also be used




         2025 A Relative Sensitivity  250




         7025 A Relative Sensitivity  250




         2796 A Relative Sensitivity 1000




     5.  To cover the range of magnesium values normally observed




         in surface waters  (0.1-20 mg/1), it is suggested that




         the burner be rotated 55.
                                   118

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                                                              (Metals)









                   Manganese - Standard Conditions








Optimum Concentration Range  0.1-20 mg/1 using the 2795 A  line




Sensitivity  0.04 mg/1




Detection Limit  0.005 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.583 gram of analytical




         reagent grade manganese dioxide, MnC"  and dissolve in 10 ml




         of HC1.  When solution is complete dilute to 1 liter with




         distilled water.  One ml equals 1 mg Mn.




     2.  Prepare dilutions of the stock solution to be used as cali-




         bration standards at the time of analysis.  Maintain an




         acid strength of 0.15% nitric acid in all calibration




         standards.




Instrumental Parameters (General)




     1.  Manganese hollow cathode lamp




     2.  Wavelength:  2795 A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:   Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28




Notes




     1.  For manganese concentrations below 0.01 mg/1, the extraction




         procedure is suggested.   The extraction is carried out at pH



         4.5-5.




     2.  Analytical sensitivity is somewhat dependent on lamp current.






                                 119

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                                                              (Metals)
                   Potassium - Standard Conditions








Optimum Concentration Range  0.01-2 mg/1 using the 7665 A line




Sensitivity  0.01 mg/1




Detection Limit  0.005 mg/1




Preparation of Standard Solutions




     1.  Stock Solution:  Dissolve 0.1907 grains of KC1 (analytical




         reagent grade), dried at 110 C, in distilled water and




         make up to 1 liter.  One ml equals 0.10 mg of potassium




         (100 mg/1).




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.




Instrumental Parameters (General)



     1.  Potassium hollow cathode lamp




     2.  Wavelength:  7665 A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Slightly oxidizing




     7.  Photomultiplier tube:  IP-21
                                  120

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                                                              (Metals)







Notes




     1.   If an IP-21 photodetector tube is  not  available,  the  IP-28




         may be used.  This  will  result in  some loss  of sensitivity.




     2.   The Osram potassium vapor-discharge lamp may also be  used




         in the Perkin-Elmer 303.   In this  case the lamp current




         should be 350 ma or the  optimum operating current.




     3.   Sodium may interfere if  present at much higher levels than




         the potassium.   This effect  can be avoided by approximately




         matching the sodium content  of the potassium standards with




         that of the sample.




     4.   Potassium absorption is  enhanced in the presence  of Na,  Li




         and Cs, especially  in a  high-temperature flame.   This en-




         hancement effect of sodium can be  eliminated by changing




         the burner height and the type of  flame used.  The burner




         assembly is set  approximately 0.05 cm  below  the optical




         light path so that  the optical light path is sliced at the




         bottom by the burner head.   A fuel-rich flame is  used (303-




         burner, airflow  7.5, acetylene flow 9.0).




     5.   The 4044 A line  may also be  used.   This line has  a sensitivity




         of 5 mg/1 for 1% absorption.




     6.   To cover the range  of potassium values normally observed in




         surface waters  (0.1-20 mg/1), it is suggested that the burner




         be rotated 75 .
                                121

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                                                              (Metals)
                    Silver - Standard Conditions








Optimum Concentration Range  0.1-20 mg/1 using the 3281 A line




Sensitivity  0.05 mg/1




Detection Limit  0.01 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Dissolve 1.575 g of AgNO, (analytical




         reagent grade) in distilled water, add 10 ml HNO, and




         make up to 1 liter.  One ml equals 1 mg of silver.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% HNO_ in all calibration




         standards.




Instrumental Parameter (General)
     1.  Silver hollow cathode lamp




     2.  Wavelength:  3281 A




     3.  Type of burner:  Boling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28
                                 122

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                                                              (Metals)
Notes




     1.   The 3382 A line may also be used.   This line has a




         relative sensitivity of 3.




     2.   Silver nitrate standards are light sensitive.




         Dilutions of the stock solution should be discarded




         after use as concentrations below  10 mg/1 are not




         stable over long periods of storage.
                                  123

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                                                              (Metals)








                    Sodium - Standard Conditions








Optimum Concentration Range  1.0-200 mg/1 using the 3302 A line




Sensitivity  0.003 mg/1




Detection Limit  0.001 mg/1




Preparation of Standard Solutions




     1.  Stock Solution:  Dissolve 2.542 g of NaCl (analytical reagent



         grade), dried at 140C, in distilled water and make up  to 1




         liter.  One ml equals 1 mg of sodium.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.




Instrumental Parameters (General)




     1.  Sodium hollow cathode lamp




     2.  Wavelength:  3302 A




     3.  Type of burner:  Doling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28
                                124

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                                                             (Metals)
Notes




     1.  For the Perkin-Elmer instrument the "290" burner is




         used to increase the concentration range of sodium




         using the most sensitive line 5890.  The burner is




         installed perpendicular (rotated 90 ) to the light




         path.  The upper concentration limit is  60 mg/1.




         without sample dilution.




     2.  The 3302 A resonance line of sodium yields a sensitivity




         of about 5 mg/1 sodium for 1% absorption and provides a




         convenient way to avoid the need to dilute more concen-




         trated solutions of sodium.




     3.  Low-temperature flames increase sensitivity by reducing




         the extent of ionization of this easily  ionized metal.




     4.  For more sensitivity the IP-21 photomultiplier tube  and




         the 5890 A line may be used to extend the range to 0.005-




         0.2 mg/1.
                                125

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                     Zinc - Standard Conditions








Optimum Concentration Range  0.1-2 mg/1 using the 2139 A line




Sensitivity  0.02 mg/1




Detection Limit  0.005 mg/1




Preparation of Standard Solution




     1.  Stock Solution:  Carefully weigh 1.00 gram of analytical




         reagent grade zinc metal and dissolve cautiously in 10 ml




         MHO,.  When solution is complete make up to 1 liter with



         distilled water.  One ml equals 1 mg Zn.




     2.  Prepare dilutions of the stock solution to be used as




         calibration standards at the time of analysis.  Maintain




         an acid strength of 0.15% HNO  in all calibration standards,




Instrumental Parameters  (General)




     1.  Zinc hollow cathode lamp




     2.  Wavelength:  2139 A




     3.  Type of burner:  Doling




     4.  Fuel:  Acetylene




     5.  Oxidant:  Air




     6.  Type of flame:  Oxidizing




     7.  Photomultiplier tube:  IP-28




Notes




     1.  High levels of silicon may interfere.




     2.  The air-acetylene flame absorbs about 25% of the energy at



         the 2139 A line.




     3.  The sensitivity may be increased by the use of low-



         temperature flames.
                                 126

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                         NITROGEN-AMMONIA




                     (Distillation  Procedure)






1.   Scope and Application




    1.1  This distillation  method covers the  determination  of




         ammonia-nitrogen,  exclusive  of total  Kjeldahl  nitrogen,  in



         surface waters,  domestic and industrial  wastes,  and  saline




         waters.   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/1




         NH /N per liter for the colorimetric procedures  and  from
           o


         1.0 to 25 mg/1  for the titrimetric procedure.




    1.3  This method  is  described for macro glassware;  however,



         micro distillation equipment may  also be used.




2.   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 boric acid.   The ammonia  in the distillate  can  be



         determined either  colorimetrically by nesslerization or



         titrimetrically with standard sulfuric acid  with the use



         of a mixed indicator,  the  choice  between these two




         procedures depending on the  concentration  of the ammonia.
                                127

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                                                (Nitrogen-Ammonia)








3.  Sample Handling and Preservation




    3.1  Until more conclusive data is obtained samples may be




         preserved by addition of 40 mg HgCl- and stored at 4CC.




         If only ammonia is to be determined on the sample it may




         be preserved with 1.0 ml of concentrated H2SO. per liter




         and stored at 4C.




4.  Interferences




    4.1  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




         nesslerization (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 hydrazine will influence the




         titrimetric results.  Some volatile compounds, such as




         certain ketones, aldehydes, and alcohols, may cause an




         off-color upon nesslerization in the distillation method.




         Some of these, such as formaldehyde, may be eliminated by




         boiling off at a low pH prior to distillation and




         nesslerization.




    4.3  Residual chlorine must also be removed by pre-treatment




         of the sample with sodium thiosulfate before distillation.
                               128

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                                                (Nitrogen-Ammonia)








    4.4  If the sample has been preserved with a mercury salt,  the




         mercury ion must be complexed with sodium thiosulfate




         prior to distillation.




5.   Apparatus




    5.1  An all-glass distilling apparatus with an 800-1000 ml




         flask.




    5.2  Spectrophotometer or filter photometer for use at 425  mp




         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  1.5 mm inside measurement from bottom.




    5.4  Erlenmeyer flasks:  The distillate is collected in 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.




6.   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 anion exchange resin.  Regeneration



         of the column should be carried out according to the




         manufacturer's instructions.
                                129

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                                            (Nitrogen-Ammonia)







6.2  Ammonium chloride, stock solution, (1.0 ml = 1.00 mg NH,-N)
                                                            O


     Dissolve 3.819 g NH.C1 in water and bring to volume in a



     1 liter volumetric flask for use as a stock solution.



6.3  Ammonium chloride, standard solution, (1.0 ml = 0.01 mg).



     Dilute 10 ml of this stock solution to 1 liter in a



     volumetric flask for use as the standard ammonium chloride



     solution.



6.4  Boric acid solution (20 g/1). - Dissolve 20 g H B0_ in



     water and dilute to 1 liter.



6.5  Mixed indicator. - Mix 2 volumes of 0.2 percent methyl red



     in 95 percent ethyl alcohol with 1 volume of 0.2 percent



     methylene blue in 95 percent ethyl alcohol.  This solution



     should be prepared fresh every 30 days.



     Note 1 - Specially denatured ethyl alcohol conforming to



     Formula 3A or 30 of the U.S. Bureau of Internal Revenue



     may be substituted for 95 percent 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 in a Pyrex bottle



     out of direct sunlight, it will remain stable for a period



     of up to 1 year.



     Note 2 - This reagent should give the characteristic color
                            130

-------
                                            (Nitrogen-Ammonia)








      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




      Na-B.O-  per liter) and dilute to 1 liter.




 6.8   Sulfuric acid,  standard1 solution,  (0.02 N,  1 ml  = 0.28  mg




      NH,-N).   Prepare  a stock solution of approximately 0.1  N




      acid  by  diluting  3 ml of concentrated  H SO.  (sp. gr.  1.84)




      to 1  liter  with (XL-free distilled water.   Dilute 200 ml of




      this  solution to  1 liter with CO--free distilled water.




      Standardize the approximately 0.02 N acid so prepared




      against  0.0200  N  Na-CO  solution.  This last solution is




      prepared by dissolving  1.060 g anhydrous  Na_CO_, oven-dried




      at 140C, and diluting  to  1 liter with C02-free  distilled




      water.




      Note  3 - An alternate and  perhaps preferable method is  to




      standardize the approximately 0.1 N H^SO.  solution against




      a 0.100  N Na-CO  solution.  By proper  dilution the 0.0200




      N acid can  then be prepared.



 6.9   Sodium hydroxide, 1  N.  Dissolve 40 g  NaOH in  ammonia-free




      water and dilute  to  1 liter.




6.10   Dechlorinating  reagents.   A number of  dechlorinating




      reagents may be used to remove residual chlorine prior  to
                            131

-------
                                               (Nitrogen-Ammonia)








         distillation.  These include:




         (a)  Sodium thiosulfate (1/70 N) :  Dissolve 3.5 g




              Na.S-O, in ammonia-free 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 NaAsO_




              in ammonia-free water and dilute to 1 liter.




7.   Procedure




    7.1  Preparation of equipment. - Add 500 ml of ammonia-free




         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. - To 400 ml of sample add 1 N NaOH




         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.  Distill 300 ml at the rate of




         6-10 ml/min. into 50 ml of 2% boric acid contained in a




         500 ml glass stoppered Erlenmeyer flask.  Dilute the




         distillate to 500 ml in the flask and nesslerize an aliquot




         to obtain an approximate value of the ammonia-nitrogen
                               132

-------
                                           (Nitrogen-Ammonia)



     concentration.   For concentrations  above 1.0  mg/1  the

     ammonia should  be determined titrimetrically.   For concen-

     trations below  this value it is  determined colorimetrically,

7.4  Determination of ammonia in distillate.  - Determine the

     ammonia content of the distillate either titrimetrically

     or colorimetrically as described below.   (See 7.4.1 and

     7.4.2).

     7.4.1  Titrimetric determination.  Add 3 drops of  the

            mixed indicator to the distillate and  titrate the

            ammonia  with the 0.02 N H^SO.,  matching the end

            point against a blank containing the same volume

            of ammonia-free water and H,BO, solution.

     7.4.2  Colorimetric determination.   Prepare a series of

            Nessler  tube standards as follows:

            ml of Standard          Cone.,  When Diluted to
        1.0 ml = 0.01 mg NH3/N     50.0 ml, mg NH3/N/liter


                0.0  (Blank)                 0.0
                0.2                          0.04
                0.5                          0.10
                1.0                          0.20
                1.5                          0.30
                2.0                          0.40
                3.0                          0.60
                4.0                          0.80

             Dilute  each tube to 50 ml with ammonia-free water,

             add 1.0 ml of Nessler reagent  and mix.  After  20

             minutes read the optical densities at 425  my
                           133

-------
                                               (Nitrogen-Ammonia)



                against the blank.   From the values  obtained

                plot optical density (absorbance)  vs concentration

                for the standard curve.

         7.4.3  It is not imperative that all standards be  distilled

                in the same manner  as the samples.  It is recommended

                that at least 2 standards Ca high  and low)  be dis-

                tilled 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.

    7.5  Determine the ammonia in the distillate by nesslerizing

         50 ml or an aliquot diluted to 50 ml and reading the

         optical density at 425 my  as described above for the

         standards.  Ammonia-nitrogen content is read from the

         standard curve.

8.  Calculations

    8.1  Titrimetric

         mg/1 NH--N = A x 0.28 x 1000
                6           S

         in which:

         A = ml 0.02 N H SO  used

         S = ml sample
                                134

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                                              (Nitrogen-Ammonia)



    8.2  Spectrophotometric

         mg/1 NH -N = A x 1000
                       0.8 S

         in which:

         A = mg NH  -N read from standard curve

         S = volume of distillate nesslerized

9.  Precision and Accuracy

    9.1  Precision  and accuracy data are not available at this time,
                               135

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                       NITROGEN,  AMMONIA




                      (Automated  Method)








1.   Scope and Application




    1.1  This method pertains  to  the determination of ammonia present




         in surface and saline waters.   Depending upon the selection of




         the size of flow cell, and extent of dilution,  concentrations




         in the range between  .01 and 20 mg/liter N present as NH, may




         be determined.









2.   Summary of Method




    2.1  The intensity of the  indophenol blue color   ,  formed by the




         reaction of ammonia with alkaline phenol hypochlorite, is meas-




         ured.  Sodium nitroprusside is used to intensify the blue color.








3.   Sample Handling and Preservation




    3.1  Preservation by addition of 40 mg HgC^ per liter and re-




         frigeration at 4C.








4.   Interferences




    4.1  In sea water, calcium and magnesium ions are present in concen-




         trations sufficient to cause precipitation problems during the




         analysis.   This problem  is eliminated by using  5% EDTA.




    4.2  Any marked variation  in  acidity or alkalinity among samples




         should be eliminated, since the intensity of the color used




         to quantify the concentration is pH dependent.   Likewise, the
                               137

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                                                   (Nitrogen,  Ammonia)








         pH of the wash water and the standard ammonia solutions should




         approximate that of the samples.  For example, if the samples




         have been preserved with 1 ml concentrated H-SO./liter, the




         wash water and standards should also contain 1 ml cone. F^SO./








5.   Apparatus




    5.1  Technicon AutoAnalyzer Unit consisting of:




         5.1.1  Sampler.




         5.1.2  Manifold.




         5.1.3  Proportioning pump.




         5.1.4  Heating bath with double delay coil.




         5.1.5  Colorimeter equipped with 15 mm tubular flow cell and




                630 or 650 my filters.




         5.1.6  Recorder.








6.   Reagents




    6.1  Distilled Water:  Special precaution must be taken to insure




         that distilled water is free of ammonia.  Such water is pre-




         pared 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.  Since organic con-




         tamination 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.
                                138

-------
                                               (Nitrogen, Ammonia)

6.2  Segmenting Fluid:   Air scrubbed with 5N H~SO..  Ammonia free
     concentrated sulfuric acid and ammonia free distilled water
     used in the acid preparation.
6.3  Sodium Phenolate:   Using a 1 liter Erlenmeyer flask, dissolve
     83 g phenol in 500 ml 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.
6.4  Sodium Hypochlorite Solution ("Chlorox"):   Dilute 100 ml of
     5% "Chlorox" to 500 ml with distilled water.  Available chlorine
     level should approximate 1%.  Since "Chlorox" is a proprietary
     product and 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.
6.5  EDTA (5%):  Dissolve 50 g of EDTA (disodiumsalt) and approxi-
     mately six pellets of NaOH in 1 liter of ammonia-free water.
6.6  Sodium Nitroprusside (0.005%):  Dissolve 0.05 g of sodium
     nitroprusside in 1 liter of ammonia-free water.
6.7  Stock Solution:  Dissolve 3.819 g of anhydrous ammonium
     chloride, NhLCl, dried at 105C, in ammonia-free water, and
     dilute to 1 liter.  1 ml = 1.0 mg NHj-N.
6.8  Standard Solution A:  Dilute 10.0 ml of stock solution to  1
     liter with ammonia-free water.  1 ml -  .01 mg NH,-N.
6.9  Standard Solution B:  Dilute 10.0 ml of standard solution A
     to 100 ml with ammonia-free water.  1 ml =  .001 mg NH--N.
                           139

-------
                                                   (Nitrogen, Ammonia)



6.10  Using standard solutions A and B, prepare the following stan-

      dards in 100 ml volumetric flasks (prepare fresh each week):

             NH3-N, mg/1       ml Standard Solution/100 ml

                                       Solution B

                0.01                       1.0
                0.02                       2.0
                0.05                       5.0
                0.10                      10.0

                                       Solution A
                0.20                       2.0
                0.50                       5.0
                0.80                       8.0
                1.00                      10.0
                1.50                      15.0
                2.00                      20.0

         Note:  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, determine its blank background.

                       Substitute Ocean Water (SOW)



                   NaCl       24.53     NaHC03    0.20

                   MgCl2       5.20     KBr       0.10

                   Na2S04     4.09     H3B03     0.03

                   CaCl2       1.16     SrCl2      .03

                   KC1         0.70     NaF        .003
                                140

-------
                                                   (Nitrogen,  Ammonia)








7.   Procedure



    7.1  For a working range of 0.01 to 2.00 NH3-N mg/1,  set up the




         manifold as shown in Figure 1.  Higher concentrations may




         be accommodated by decreasing sample size and/or through




         dilution of sample.



    7.2  Allow both colorimeter (with 650 my filters and  15 mm flow




         cell) and recorder to warm up for 30 minutes.  Run a  baseline




         with all reagents, feeding ammonia-free water  through sample




         line.  Adjust dark current and operative opening on colori-




         meter to obtain stable baseline.




    7.3  Place a distilled water wash tube in alternate openings in




         sampler and set sample timing at 2.0 minutes.  All tubes must




         be rinsed with ammonia-free water before use.




    7.4  Arrange ammonia standards in sampler in order  of decreasing




         concentration of nitrogen.  Complete loading of  sampler tray




         with unknown samples.




    7.5  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.
                               141

-------
                                                    (Nitrogen, Ammonia)






9.  Precision and Accuracy


    9.1  In a single  laboratory  (AQC), using surface water samples


         at concentrations of 1.41, 0.77, 0.59, and 0.43 mg NHj-N/l",


         the standard deviation was 0.005.


    9.2  In a single  laboratory  (AQC), using surface water samples


         at concentrations of 0.16 and 1.44 mg NH -N/l, recoveries were
                                                 O

         107% and 99%, respectively.





                             References
1.  D. Van Slyke and A. Miller,  "Determination of Ammonia in Blood,"


    J. Biol. Chem.  102, 499  (1933).


2.  B. O'Connor, R. Dobbs, B. Villiers, and  R. Dean, "Laboratory Dis-


    tillation of Municipal Waste Effluents," JWPCP _39_,  R 25  (1967).


3.  J. E. O'Brien  and J.  Fiore,  "Ammonia  Determination  by Automatic


    Analysis," Wastes Engineering 33,  352 (1962).


4.  A wetting agent recommended  and  supplied by  the Technicon Corporation


    for use in Autoanalyzers.


5.  ASTM "Manual on Industrial Water and  Industrial Waste Water,"


    2nd Ed., 1966  printing, 418.
                                142

-------
     FWPCA Methods for Chemical Analysis of Water and Wastes (November.1969)
                        Suggested Changes and.Errata     ,
Page
6
Section
Table 1
Line
Solids,
filterabl
13
14
17
21
         Table 1
           Threshold odor
 8       Table 2    Nitrogen,
                     ammonia
         Table 2    Nitrogen,
                     nitrate-nitrite
         Table 2    Oil & Grease
         Table 2    Phosphorus
6.4
Dilution
 Table
6.4.1
                Change

Change 00515 to 70300


For TO at 60C; add STORET #00086 ,  .

Write in TO at 40C and STORET #00087

Add footnote 1 - "HgCl2 will complex

with NH~; this complex may not be
broken in dist'n. step"

Add footnote 2 - "HgCl will destroy
reduction column in cadmium reduction
method"

Change preservative to:  "5 ml cone.
HC1 per liter - 4C"

Add footnote 3 - "Must have minimum
of 50 mg Cl/liter in sample to prevent
precipitation when HgCl is used"

Change to read;  "Dissolve 1.060 gm of
anhydrous sodium carbonate (oven dried
at 140 C for 1 hour) in distilled water
and dilute to 1.0 liter.  1.0 ml =
1.00 mg CaC03

Change mg/1 to mg/1 as CaCO~
Remove page 17 and replace with
accompanying new page 17

Formula should be:

            (ml K2Cr20 ) x (0.025)
                                          Normality =
                                                      [ml Fe(NH4)2(S04)2]
29
7.6
Change 800 ml to 800 mg/1
29
Footnote
Reference should read:  "Burns, E.R.,
 Marshall,  C.,  Journal WPCF,  37,
 pp 1716-1721  (1965).

-------
 Page    Section     Line

 30      8.1



 54      Ref 2.

 85      Figure 1
                                                 Change
139
143
149
6.6
Figure 1
7.2
Note 2
                           Formula  should be
                mg/1 COD = [(A-B)C x 8000 - -50 D] x 1.20
                                 ml sample

               Change Ely to Elly

               Change sample rate from 3.90 to 0. 8

               and distilled water rate from 0.8 to 3.90
               (color code P-W and R-R is correct but
                rates were reversed)

               Change (0.005%) to (0.057,) and 0.05 gm
               to 0. 5 gm
Change
                              to 5N
Sentence should read "Alternately digest
the sample with 1 Kel-Pac (Olin-Matheson)
opened or unopened and 20 ml of cone.
157      8.1.3

173-4    6.7
174

175

207



240
251
6.10

6.11

8.2



7.8




7.4
               Change 360C to 390C and 330C to 360C

               At end of paragraph 6.7 on page 174 insert
               paragraph 6.7.1 to read:  "Dilute 90 ml of
               6.7 to 4 liters with distilled water to
               obtain working solution"

               Change potassium nitrite to sodium nitrite

               Change potassium nitrite to sodium nitrite

               Insert sentence "If sample has been
               preserved with HC1 and pH is below 3,
               omit acid addition at this step"

               Change "Add 40 ml of sulfuric acid
               solution to 1 liter" --- to "Add 40 ml
               of strong acid solution (reagent 7.6)
               to 1 liter"

               Insert (reagent 7.1) after "sulfuric
               acid solution"

-------
                     BIOCHEMICAL OXYGEN DEMAND








1.  Scope and Application




    1.1  The biochemical oxygen demand test (BOD) 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.




    1.3  Ancillary information relating to oxygen demanding charac-




         teristics and carbon content of wastewaters can be gained




         by applying the Total Organic Carbon (TOC) and Chemical




         Oxygen Demand (COD) Tests.
                                  17

-------
                                                             (.BOD)
    1,4  Because of the effect of local conditions, types of

         samples to be tested and variabilities in this type of

         procedure, FWPCA has not selected a specific standard

         test for the determination of Biochemical Oxygen Demand.


2.  Procedure

    2.1  Directions for conducting the BOD test are found in:

           Standard Methods for the Examination of Water and
           Wastewater, 12 Edition (1965), pp. 415-421.

           ASTM Standards (1968) Part 23, Water; Atmospheric
           Analyses, pp. 727-732.

    2.2  Determinations of dissolved oxygen in the BOD test may be

         made by use of either the Modified Winkler with Full-Bottle

         Technique (p. 55) or the Probe Method (p. 65) in this

         manual.


3.  Precision and Accuracy

    3.1  In 34  laboratories, the standard deviation of the BOD test,

      |  using  a glucose-glutamic acid mixture, was 31 mg/1 at a

         mean BOD concentration of 184 mg/1.  In a single laboratory,

         the precision was 11 mg/1 at a BOD of 218 mg/1 (Analytical

         Reference Service, PHS).

    3.2  There  is no method available to determine the accuracy of

         the BOD test.
                                   18

-------
CO


1
SMALL MIXING COIL (Sm]
LARGE MIXING COIL (Lm) '
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Lm
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(mcjj) HEATING BATH
1 0000

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COLORIMETER
15mm TUBULAR f/c
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PR
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P
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G G
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W
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1 '
ml/min
,2.90 SAMPLE
,
^0.80 5% EDTA ^lS-
42.00 FILTERED SAMPLE f3 ^
,2.00 AIR* CONTINUOUS FILTER
40.60 Na PHENOLATE
0.60 NaOCI
0.80 NITROPRUSSIDE
.2.50 WASTE
PUMP
RECORDER
                      650 mji FILTERS
      SAMPLING TIME:2.0  MINUTES
      WASH TUBES:  ONE

'SCRUBBED THROUGH 5NH2 $04
                                    FIGURE  1. AMMONIA  MANIFOLD

-------
                      NITROGEN KJELDAHL,  TOTAL








1.   Scope and Application




    1.1  This method covers  the determination of total  Kjeldahl  nitrogen




         in surface waters,  domestic and  industrial  wastes,  and  saline




         waters.   The procedure converts  nitrogen of components  of bio-




         logical  origin such as amino acids,  proteins and peptides to




         ammonia, but may not convert the nitrogenous compounds  of some




         industrial wastes such as  amines, nitro'compounds,  hydrazones,




         oximes,  semi-carbazones and some refractory tertiary amines.




    1.2  Two alternatives are listed for  the  determination of ammonia




         after distillation; the titrimetric  method  which is applicable




         to concentrations above 1  mg N/liter and the Nesslerization




         method which is applicable to concentrations below 1 mg N/liter.




    1.3  This method is described for a macro system of glassware;  .



         however, micro glassware which does  not change the chemistry of




         the procedure is equally applicable.








2.   Definitions




    2.1  Total Kjeldahl is defined  as the sum of free ammonia and




         organic nitrogen compounds which are converted to ammonium




         sulfate (NH.)?SO., under the conditions of digestion




         described below.




    2.2  Organic Kjeldahl Nitrogen  is defined as the difference




         obtained by subtracting the free ammonia value  (cf Nitrogen,




         Ammonia, this Manual) from the total Kjeldahl nitrogen value.
                                 145

-------
                                              (Nitrogen Kjeldahl, Total)








         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 concentrated sulfuric




         acid, K?SO. and HgSO. and evaporated until SO, fumes are ob-




         tained 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 either by nesslerization or




         titrimetrically.








4.  Sample Handling and Preservation




    4.1  Samples may be preserved by addition of 40 mg HgCl_ and stored




         at 4C.  Even when so preserved, conversion of organic nitrogen




         to ammonia may occur.  Preserved samples should be analyzed as



         soon as possible.








5.  Apparatus




    5.1  Digestion apparatus.  A Kjeldahl digestion apparatus with 800 ml




         flasks and suction takeoff to remove S0_ fumes and water is re-




         quired.  Use of micro-Kjeldahl equipment is also permissible.




    5.2  Distillation apparatus.  The Kjeldahl flask is connected to a




         condenser and an adaptor so that the distillate can be collected




         for nesslerization or in indicating H,BO_ solution for titration.
                                 146

-------
                                          (Nitrogen Kjeldahl,  Total)



7.2  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 - 100                       25.0

     Dilute the sample,  if required, to  500 ml,  and add 100 ml

     sulfuric-acid -  mercuric sulfate -  potassium sulfate solution

     (Note 2),  and evaporate  the mixture in the  Kjeldahl apparatus

     until SO,  fumes  are given  off and the solution turns colorless

     or pale yellow.   Cool the  residue and add 300 ml water.

     Note 2 - Alternately digest the sample with 1 Kel-Pac

     (Olin-Matheson)  and 20 ml  H SO  .

7.3  Make the digestate  alkaline by  careful addition of the sodium

     hydroxide-thiosulfate solution  without mixing.

     (Note - Slow addition of the heavy  caustic  solution down the

     tilted neck of the  digestion flask  will cause the heavier so-

     lution to  underlay  the  aqueous  sulfuric acid solution without

     loss of free ammonia.   Do  not mix until the digestion flask has

     been connected to the distillation  apparatus.)

7.4  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 in the receiving flask.
                              149

-------
                                          (Nitrogen Kjeldahl, Total)







7.5  Distill 300 ml at the rate of 6-10 ml/min., into 50 ml of 2%



     boric acid contained in a 500-ml glass stoppered Erlenmeyer



     flask.



     7.5.1  If it is anticipated that the ammonia measurement will



            be by nesslerization, 50 ml of boric acid is preferred.



            If, however, sufficient ammonia is present to permit



            titration of a larger volume of boric acid, either 100



            or 200 ml, may be used.



7.6  Dilute the distillate to 500 ml in the flask and nesslerize



     an aliquot, to obtain an approximate value of the ammonia-



     nitrogen concentration.   For concentrations above 1.0 mg/1



     the ammonia should be determined titrimetrically.  For con-



     centrations below this value it is determined colorimetrically.



7.7  Determination of ammonia in distillate. - Determine the



     ammonia content of the distillate either titrimetrically or



     colorimetrically as described below.



     7.7.1  Titrimetric determination.  Add 3 drops of the mixed



            indicator to the  distillate and titrate the ammonia



            with the 0.02 N H-SO., matching the endpoint against



            a blank containing the same volume of ammonia-free



            water and H BO  solution.
                       o  o
                            . 150

-------
                                              (Nitrogen  Kjeldahl,  Total)








    5.3  Spectrophotometer for use  at  400  to  425  my  with a light path  of




         1 cm or longer.




    5.4  Nessler tubes,  tall  form,  50  ml.








6.  Reagents




    6.1  Distilled waters  should be free of ammonia.   Such water is  best




         prepared by the passage of distilled water  through an  ion ex-




         change 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.




    6.2  Mercuric sulfate  solution.  Dissolve 8 g red, mercuric oxide  (HgO)




         in 50 ml of 1:5 sulfuric acid and dilute to 100 ml with distilled




         water.




    6.3  Sulfuric acid-mercuric sulfate-potassium sulfate solution.




         Dissolve 267 g  K?SO. in 1300  ml water and add 400 ml concentrated




         H?SO..  Add 50  ml mercuric sulfate solution and dilute to 2 liters.




    6.4  Sodium hydroxide-sodium thiosulfate  solution.  Dissolve 500 g




         NaOH and 25 g Na-S^O  5H 0 in water  and  dilute  to 1 liter.




    6.5  Phenolphthalein indicator  solution.   Dissolve 5 g phenolphthalein




         in 500 ml 95% ethyl  alcohol or isopropanol  and  add 500 ml water.




         Add 0.02 NaOH dropwise until  a faint, pink  color appears.




    6.6  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.
                                 147

-------
                                              (Nitrogen Kjeldahl,  Total)







    6.7  Boric acid solution.  Dissolve 20 g boric acid, H BO   in water



         and dilute to 1 liter with water.



    6.8  Sulfuric acid titrant, 0.020 N.   (1-00 ml = 0.28 mg N.)



    6.9  Ammonium chloride, stock solution,  (1.0 ml = 1.0 mg NH /N).



         Dissolve 3.819 g NH4C1 in water and make up to 1.0 liter  with



         ammonia free water.



   6.10  Ammonium chloride, standard solution, (1.0 ml = 0.01 mg NH,/N).
                                                                   o


         Dilute 10.0 ml of the stock solution to 1.0 liter.



   6.11  Nessler reagent. - Dissolve 100  g of mercuric iodide and  70  g



         of potassium iodide in a small volume 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.  The solution



         is stable for at least one year if stored in a pyrex bottle  out



         of direct sunlight.



         Note - Reagents 6.9, 6.10, and 6.11 are identical to reagents



         6.2, 6.3 and 6.6 described under Nitrogen, Ammonia.







7.   Procedure



    7.1  The distillation apparatus should be pre-steamed before use  by



         distilling a 1:1 mixture of ammonia-free water and sodium



         hydroxide-sodium thiosulfate solution 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).
                                 148

-------
                                          (Nitrogen  Kjeldahl, Total)



     7.7.2  Colorimetric determination.   Prepare  a series  of Nessler

            tube standards  as  follows:

               ml of Standard           Cone.,  When Diluted to
           1.0 ml =  0.01 mg NH'/N     50.0  ml,  mg NH /N/liter


                  0.0  (Blank)                  0.0
                  0.2                          0.04
                  0.5                          0.10
                  1.0                          0.20
                  1.5                          0.30
                  2.0                          0.40
                  3.0                          0.60
                  4.0                          0.80

            Dilute each  tube to 50  ml  with  ammonia-free  water,  add

            1.0 ml of Nessler  reagent  and mix.  After 20 minutes  read

            the optical  densities at 425  my against  the  blank.  From

            the values obtained plot optical density (absorbance)  vs

            concentration for  the standard  curve.

     7.7.3  It is not imperative that  all standards  be distilled  in

            the same manner as  the  samples.  It is recommended  that

            at least 2 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.

7.8  Determine the ammonia in  the distillate by nesslerizing 50 ml

     or an aliquot diluted to  50 ml and reading the  optical density

     at 425 my as described above for  the Standards.  Ammonia-

     nitrogen is read from the standard curve.
                            151

-------
                                              (Nitrogen  Kjeldahl, Total)





8.  Calculation


    8.1  If the titrimetric procedure is used calculate Total Kjeldahl


         Nitrogen, in mg/1, in the original sample as follows:

              T * i - ij ui  *         /i   (A-B)x N x F x 1000
              Total Kjeldahl nitrogen, mg/1 =	^	
                                                       O


              where:


              A  =  milliliters of standard 0.020 N H_SO. solution used


                    in titrating sample.


              B  =  milliliters of standard 0.020 N H?SO  solution used


                    in titrating blank.


              N  =  normality of sulfuric acid solution.


              F  =  millequivalent weight of nitrogen (14 mg).


              S  =  milliliters of sample digested.


         If the sulfuric acid is exactly 0.02 N the formula is shortened


         to:


                       TKN, mg/1  .   (A-B) X 28
                                           O


    8.2  If the Nessler procedure is used, calculate the Total Kjeldahl


         Nitrogen, in mg/1, in the original sample as follows:


                       TKN, mg/1  =  A X 100
                             *       0.8 x  S


         where:


         A  =  mg NH_/N read from curve.
                    O

         S  =  volume of distillate nesslerized.


    8.3  Calculate Organic Kjeldahl Nitrogen in mg/1, as follows:


                          Organic Kjeldahl Nitrogen  =  TKN - NH /N





9.  Precision


    9.1  Precision and accuracy data are not available at this time.
                                 152

-------
                    NITROGEN,  KJELDAHL,  TOTAL




                   (Automated  Phenolate  Method)








1.   Scope and Application



    1.1  This automated method may be used to determine Kjeldahl




         nitrogen in surface waters,  domestic and industrial wastes,




         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 sulfuric 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 hypochlorite reagent.  This treatment forms a blue




         color designated as indophenol.  Sodium nitropruss"ide, 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 compounds which are converted to (NH^^SO, under




         the conditions of digestion which are specified below.
                                153

-------
                                              (Nitrogen, Kjeldahl,  Total)








    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 deter-




         mined directly by removal of ammonia before digestion.








4.  Sample Handling and Preservation




    4.1  Preservation by addition of 40 mg HgCl? per liter and refri-




         geration at 4C is necessary.








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  Technicon AutoAnalyzer consisting of:




         6.1.1  Sampler II, equipped with continuous mixer.




         6.1.2  Two proportioning pumps.




         6.1.3  Manifold I




         6.1.4  Manifold II




         6.1.5  Continuous Digester




         6.1.6  Peristaltic pump




         6.1.7  Five-galIon Carboy fume-trap




         6.1.8  80C Heating bath




         6.1.9  Colorimeter equipped with 50 mm tubular flow cell and




                630 my filters.




        6.1.10  Recorder equipped with range expander.
                                  154

-------
                                                (Nitrogen, Kjeldahl, Total)








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.




    7.2  Sulfuric acid: As it readily absorbs ammonia, special pre-




         caution 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  ethylenediamine




         tetraacetate in 1 liter of distilled water.  Adjust pH to



         10.5-11.




    7.4  Sodium  hydroxide  (30% solution): Dissolve  30 g NaOH in




         1 liter of distilled  water.   (May  have  to  be adjusted  to




         give  neutralization in the water-jacketed  mixing coil).




    7.5  Sodium  nitroprusside, Stock  (1% solution):  Dissolve 10 g




         Na2Fe(CN)5N0.2H20 in  1 liter  distilled  H20.




    7.6  Sodium  nitroprusside, working solution: Dilute 50 ml  stock




         solution to 1  liter with distilled water.
                                  155

-------
                                           (Nitrogen, Kjeldahl,  Total)



 7.7  Alkaline phenol reagent:  Pour 550 mis liquid phenol (88-90%)

      slowly with mixing and cooling into 1 liter of 40% NaOH.

      Make up to 2 liters with distilled water.

 7.8  Sodium hypochlorite (1% solution):  Dilute commercial

      "Clorox" - 200 ml to 1 liter with distilled water.

 7.9  Digestion mixture:  Place 2 g HgO in a 2-liter container.

      Slowly add, with stirring, 300 ml of acid water (100 ml H2SO  -

      200 ml HJ3) and stir until cool.  Add 100 ml 10% K2SO..  Dilute

      to a volume of 2 liters with cone, sulfuric acid (approximately

      500 ml at a time, allowing time for cooling).

7.10  Stock Solution:  Dissolve 4.7619 g of pre-dried ammonium

      sulfate in distilled water and dilute to 1.0 liter.  Dissolve

      2.1276 g of urea in distilled water and dilute to 1.0 liter.

      Dissolve 30.5263 g of glutamic acid in distilled water and

      dilute to 1.0 liter.  1 ml  =  1.0 mg N.

7.11  Standard Solution:  Dilute 10.0 ml of respective stock solution

      to 1.0 liter.  1 ml  =  0.01 mg N.

      7.11.1  Using the respective standard solutions, prepare the

              following standards in 100.0-ml volumetric flasks:


              Cone., mg N/l           ml Standard Sdlutibn/100 ml

                  0.00                          0.0
                  0.05                          0.5
                  0.10                          1.0
                  0.20                          2.0
                  0.40                          4.0
                  0.60                          6.0
                  0.80                          8.0
                  1.00                         10.0
                  1.50                         15.0
                  2.00                         20.0
                               156

-------
                                               (Nitrogen,  Kjeldahl, Total)








8.   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 contro.l




                of three key  factors is  required  to  enable Manifold




                No.  2 to receive the mandatory representative feed.




                First,  the digestate 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 digestate  in digester.   Second, in maintaining even




                flow from  the 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




                in 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 Hydrion B paper.




         8.1.3  The digester temperature is 360C for the first stage




                and 330C 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
                                  157

-------
                                                   (Nitrogen, Kjeldahl,  Total)








            through the sample line.  Adjust dark current and operative




            opening on colorimeter to obtain stable baseline.




       8.3  Set sampling rate of Sample II at 20 samples per hour, using




            a wash to sample ratio of 2 to 1.




       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.




            8.5.1  If equipment is operating properly, 100% nitrogen




                   recovery should be obtained for glutamic acid and




                   urea when compared to ammonium sulfate standards.








 9.  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.








10.  Precision and Accuracy




    10.1  Precision and accuracy data are not available at this time.
                                    158

-------
                                                 (Nitrogen,  Kjeldahl, Total)









                             References





1.   Kammerer,  P.A.;  Rodel,  M.G.;  Hughes,  R.A.;  and Lee, G.F.;




    "Low Level Kjeldahl Nitrogen  Determination  on the Technicon




    AutoAnalyzer."  Environmental Science and Technology.  1:4:340




    (April 1967).




2.   McDaniel,  William H.;  Hemphill,  R.N.; Donaldson, W.T.; "Automatic




    Determination of Total  Kjeldahl  Nitrogen in Estuarine Waters."




    Presented  at Technicon Symposium on  Automation in Analytical




    Chemistry, New York, October  3,  1967.




3.   B.  O'Connor,  Dobbs, Villiers, and Dean,  "Laboratory Distillation of




    Municipal  Waste Effluents".   JWPCP 39^, R 25, 1967.
                                   159

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                          NITROGEN,  NITRATE
1.  Scope and Application




    1.1  This method is applicable to the analysis of surface waters,




         domestic and industrial wastes,  and saline waters.   Modifi-




         cation 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 NO^-N/




         liter.



2.  Summary of Method




    2.1  This method is based upon the reaction of the nitrate ion with




         brucine sulfate in a 13 N H-SO.  solution at a temperature of




         100C.  The color of the resulting complex is measured  at 410  my.




         Temperature control of the color reaction is extremely  critical.



3.  Sample Handling and Preservation




    3.1  Until more conclusive data is obtained, samples may be  pre-




         served by addition of 40 mg HgCl2 per liter and storage at 4C.




4.  Interferences




    4.1  Dissolved organic matter will cause an off color in 13  N




         t^SO^ and must be compensated for by additions of all reagents.




         except the brucine-sulfanilic acid reagent.  This also  applies




         to natural color present not due to dissolved organics.
                                      165

-------
                                                       (Nitrogen,  Nitrate)








    4.2  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 by the




         addition of orthotolidine reagent.




    4.4  Residual chlorine interference is eliminated by the




         addition of sodium arsenite.




    4.5  Ferrous and ferric iron and quadrivalent manganese give




         slight positive interference, 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



         optical densities at 410 my and capable of accommodating 25 mm




         diameter cells.




    5.2  Sufficient number of 25 mm diameter matched tubes for reagent




         blanks, standards, and samples.



    5.3  Neoprene coated wire racks to hold 25 mm diameter tubes.




    5.4  Water bath suitable for use at 100C.  This bath should




         contain a stirring mechanism so that all tubes are at same




         temperature and should be of sufficient capacity to accept
                                 166

-------
                                                       (Nitrogen,  Nitrate)







         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.



6.   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 (300 g/1).   Dissolve 300 g NaCl



         in distilled water and dilute to 1000 ml.



    6.3  Sulfuric acid solution.  Carefully add 500 ml H SO  (sp.



         gr. 1.84) to 125 ml distilled water.  Cool and keep



         tightly stoppered to prevent absorption of atmospheric



         moisture.



    6.4  Brucine-sulfanilic acid reagent.  Dissolve 1 g brucine



         sulfate  [(C23H26N204)2.H2S04.7H20] and 0.1 g sulfanilic



         acid (NH2C6H4S03H.H20) in 70 ml hot distilled water.  Add



         3 ml concentrated HC1, cool, mix and dilute to 100 ml.



         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 ml = 0.1 mg NO,-N).
                                                           O


         Dissolve 0.7218 g anhydrous potassium nitrate (KNO_) in



         distilled water and dilute to 1 liter.
                                 167

-------
                                                       (Nitrogen,  Nitrate)








    6.6  Potassium nitrate standard solution (1 ml = 0.01 mg NO,-N).




         Dilute 100 ml of the stock solution to 1 liter.   This




         standard solution should be prepared fresh weekly.




    6.7  Acetic acid (1 + 3).  Dilute 1 vol. glacial acetic  acid




         (CH COOH) with 3 volumes of distilled water.




7.   Procedure




    7.1  Adjust the pH of the samples to approximately pH 7  with




         1:3 acetic acid and, if necessary, filter through a 0.45  u




         pore size filter.




    7.2  Set up the required number of matched tubes in the  rack to




         handle reagent blank, standards and samples.  It is




         suggested that tubes be spaced evenly throughout the rack




         to allow for even flow of bath water between the tubes.




         Even spacing of tubes should assist in achieving uniform




         heating of all tubes.




    7.3  If it is necessary to correct for color or dissolved organic




         matter which will cause color on heating, a set of  duplicate




         tubes must be used to which all reagents except the brucine-




         sulfanilic acid has been added.




    7.4  Pipette 10 ml or an aliquot of the samples diluted  to  10  ml



         into the sample tubes.




    7.5  If the samples are saline, add 2.0 ml of the 30 percent




         sodium chloride solution to the reagent blank, standards  and




         samples.  For fresh water samples, sodium chloride  solution
                                 168

-------
                                                    (Nitrogen-Nitrate)








     may be omitted.   Mix contents  of tubes  of swirling  and




     place rack in cold water bath  (0-10C).




7.6  Pipette 10 ml of sulfuric acid solution 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-sulfanilic  acid reagent to each  tube




     (except the interference control tubes)  and carefully mix




     by swirling, then place the rack of tubes in the boiling




     water bath for exactly 25 minutes.  CAUTION:  Immersion




     of the tube rack into the bath should not decrease  the




     temperature of the bath.  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 theprocedure  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




    (20-25).




7.9  Dry tubes and read optical density against the reagent blank




     at 410 my.
                             169

-------
                                                        (Nitrogen, Nitrate)
8.  Calculation



    8.1  Obtain a standard curve by plotting the optical densities



         of standards run by the above procedure against mg NCL-N.



         (The color reaction does not always follow Beer's law.)



    8.2  Subtract the absorbance of the sample without the brucine-



         sulfanilic reagent from the absorbance of the sample



         containing brucine-sulfanilic acid and read the optical



         density in mg NCL-N.  Multiply by factor for converting mg
                         J


         per aliquot of sample to mg per liter.
              NCL-N mg/1  = mg NCL-N from curve x
1000
                                                 ml sample



9.  Precision and Accuracy



    9.1  Precision and  accuracy data are not available at this time.
                                  170

-------
                   NITROGEN,  NITRATE AND NITRITE



              (Automated Hydrazine Reduction Method)






1.   Scope and Application



    1.1  This method is  applicable to surface waters,  and domestic



         and industrial  wastes which contain less than 500 mg/1



         calcium.   The applicable range of this  method is 0.05-10



         mg/1 nitrite or nitrate nitrogen.   Approximately 20



         samples per hour can be analyzed.



2.   Summary of Method



    2.1  This method, using the Technicon AutoAnalyzer, determines



         NCL-N by the conventional diazotization-coupling reaction.



         The NCL-N is reduced with hydrazine sulfate in another



         portion of the sample and the nitrite thus formed is



         determined in the usual manner.



    2.2  Subtraction of the NCL-N originally present in the sample



         from the total NCL-N found will give the original NCL-N
                          ^                                  J


         concentration in terms of NCL-N.



3.   Sample Handling and Preservation



    3.1  Preservation by addition of 40 mg HgCl2 per liter and



         refrigeration at 4C.



4.   Interferences



    4.1  The following table lists the concentration of ions that



         cause no interference in the determination of nitrite and



         nitrate nitrogen.  The same interfering ion concentration
                                171

-------
                                             (Nitrogen,  Nitrate and Nitrite)







         applies to either nitrite or nitrate:



                Ion         mg/1 Ion Not Causing Interference



                Cl~                  30,000



                P04'3                    50




                S"2                    Note



                NH -N                    80
                  o



                Mg+2                     75



                Ca+2                    240



                Fe+3                     30



                ABS                      60



         Note 1. -- The apparent NO, and NO- concentrations varied 



         10 percent with concentrations of sulfide ion up to 10 mg/1.



    4.2  The pH of the samples should be between 6 and 9.



5.   Apparatus



    5.1  Technicon AutoAnalyzer consisting of:



         5.1.1  Two proportional pumps.



         5.1.2  Two colorimeters each with an 8 mm flow-through cell



                and 520 my filters.



         5.1.3  One continuous filter.



         5.1.4  One Sampler I.



         5.1.5  Two recorders.



         5.1.6  One 38C temperature bath.



         5.1.7  Two time delay coils.
                                172

-------
                                               (Nitrogen,  Nitrate and Nitrite)







6.   Reagents



    6.1  Color developing reagent:   To approximately 3 liters of



         distilled water add 400 ml concentrated phosphoric acid



         (sp. gr.  1.834), 60 g sulfanilamide (H N-C H  SO  NH )
                                               ^   OH*   ^   


         followed by 3.0 g N (l-Naphthyl)ethylene-diamine dihydro-



         chloride.  Dilute the solution to 4 liters with distilled



         water and store in a dark bottle in the refrigerator.



         This solution is stable for approximately 1 month.



         Note 2 -- It may be necessary to apply heat in order to



         dissolve the sulfanilamide.



    6.2  Copper sulfate; stock solution:  Dissolve 2.5 g of copper



         sulfate  (CuSO,.5H 0) in distilled water and dilute to 1



         liter.



    6.3  Copper sulfate; dilute solution:  Dilute 20 ml of stock



         solution to 2 liters with distilled water.



    6.4  Sodium hydroxide; stock solution, (10 N):  Dissolve 400 g



         NaOH in  750 ml distilled water, cool and dilute to  1  liter.



    6.5  Sodium hydroxide(1.ON):  Dilute 100 ml of stock NaOH



         solution to 1 liter.



    6.6  Sodium hydroxide(0.3N):  Dilute 60 ml of stock NaOH to  2



         liters.



    6.7  Hydrazine  sulfate  solution:   Dissolve 54.92  g of  hydrazine



         sulfate  (N_H  .H  SO  ) in 1800  ml of distilled water  and  dilute
                                 173

-------
                                            (Nitrogen,  Nitrate and Nitrite)
      to  2000 ml.   This solution is stable for approximately



      6 months .



      CAUTION:  Toxic if ingested.   Mark container with warning.



 6.8  Potassium nitrate; stock solution (1000 mg/1 .  NO,-N) :



      Dissolve 7.2180 g of KN03, oven dried at 100-105C for



      2 hours, in distilled water and dilute to 1000  ml.  Add



      1 ml chloroform as a preservative.  Stable for  6 months.



 6.9  Potassium nitrate; standard solution (100 mg/1  NCL-N) :
                                                       o


      Dilute 50 ml of stock KNO  solution to 500 ml in a
                               o


      volumetric flask.  From this dilute solution prepare the



      following standards in 500 ml volumetric flasks:



           mg/1 NO--N            ml Standard Solution
              0.4                        2.0



              1.0                        5.0



              1.6                        8.0



              3.0                       15.0



              5.0                       25.0



              7.0                       35.0



             10.0                       50.0



6.10  Potassium nitrite; stock solution (1000 mg/1 NO_-N) :  Dissolve



      4.9260 g NaNO  , oven dried at 100-105C for two hours, in



      distilled water and dilute to 1000 ml.  Add 1 ml chloroform as



      preservative.  Store in the refrigerator.  Stable for 1 month.
                              174

-------
                                                (Nitrogen, Nitrate  and Nitrite)




    6.11  Potassium nitrite;  standard  solution  (100 mg/1):   Dilute
                    
          50 ml  of stock  NaNCL  solution  to 500  ml  in  a  volumetric

          flask.   From this dilute  solution prepare the same

          volumetric standards  as   in  6.9.  Prepare fresh  each  week.

7.   Procedure

    7.1  Set up  the manifold  as shown  in Figures  1 and  2.  Allow

         both colorimeter (with the proper filters) and recorder to

         warm up for 30 minutes, then  run a baseline  with  all reagents,

         feeding distilled water through the  sample line.  Adjust dark

         current and operative  opening on each  colorimeter.  Adjust

         baseline to 0.01 optical density.  Place  a distilled water

         wash tube in alternate openings on sampler and set  sample

         timing  at 1.5 minutes.

    7.2  Run a 2.0 mg/1 NO -N and a 2.0  mg/1  NO--N standard  through

         the system to check  for 100%  reduction of nitrate to nitrite.

         The two peaks should be of equal height.  If the  NO, peak  is

         lower than that  of the N02 peak, the temperature  of the

         reduction bath should  be increased until  they  are equal.   If

         the NO, peak is  higher than the nitrate,  the temperature should

         be reduced.  When the  correct temperature of the  bath  has  been

         determined, no further adjustment should be  necessary.

    7.3  Arrange standards in sampler  in N0~-N0,  order  with  increasing

         concentration of nitrogen. Place unknown samples in sampler
                                 175

-------
                                             (Nitrogen, Nitrate and Nitrite)








         tubes and place in alternate openings of sampler.  A NO-




         and NO, standard of equal nitrogen  concentration should




         be placed after every 10 samples as a further check on




         the system and to more easily identify peaks.




8.  Calculation



    8.1  Prepare standard curve by plotting peak heights of pro-




         cessed standards against known concentrations.  Compute




         concentrations of samples by comparing sample peak heights




         with standard curve.




    8.2  Subtract the NC>2 concentration in the sample from the total




         NC>2 found (nitrite plus nitrate) on the reduction side to




         calculate the NO^ concentration in the sample.




9.  Precision and Accuracy




    9.1  In a single laboratory (AQC), using surface water samples




         at concentrations of 0.1, 0.2, 0.8, and 2.1 mg-N/-^, the




         standard deviations were 0.0, 0.04, 0.05, and 0.05,




         respectively.




    9.2  In a single laboratory (AQC), using surface water samples




         at concentrations of 0.2 and 2.2 mg-N/^, recoveries were




         100% and 96%, respectively.



                               References




1.  D. Jenkins and L. Medsker, "Brucine Method for Determination of




    Nitrate in Ocean, Estuarine, and Fresh Waters."  Anal. Chem.,




    36^ 610 (1964).




2.  L. Kamphake, S. Hannah, and J. Cohen, "Automated Analysis for




    Nitrate by Hydrazine Reduction."  Water Research, 1, 205 (1967).
                                 176

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-------
                     NITROGEN,  NITRATE-NITRITE



                (Automated Cadmium Reduction Method)





1.   Scope and Application



    1.1  This method pertains  to the determination of nitrates  and



         nitrites,  singly or combined,  present in surface and saline



         waters.   The prescribed specifications permit analyses of



         samples  in the range  of 0.05 to 10 mg/liter, N present as



         NO .
           O


2.   Summary of Method^


                         (2)
    2.1  The initial step  J is to reduce the nitrates to nitrites



         by using a cadmium-copper catalyst.  The nitrites (those



         originally present plus reduced nitrates) are then reacted



         with sulfanilamide to form the diazo compound which is then



         coupled in an acid solution (pH 2.0 - 2.5) with N-l naphthyl-



         ethylenediamine hydrochloride to form the azo dye.  The azo



         dye intensity, which  is proportional to the nitrate concen-



         tration, is then measured.  Separate rather than combined



         nitrate-nitrite values are readily obtainable by carrying



         out the procedurefirst with, and then without, the initial Cd-Cu



         reduction step.



3.   Sample Handling and Preservation



    3.1  Preservation by addition of 40 mg HgCl2 per liter and refrig-



         eration at 4C is necessary.
                                181

-------
                                                 (Nitrogen, Nitrate-Nitrite)








4.   Interferences




    4.1  Ammonia and primary amines which are frequently present in




         natural waters may react to some extent with nitrites- to




         form nitrogen.  Thus,, since, as in nature, the sample is




         not stable, the analyses should be performed as soon as




         possible.




    4.2  In surface waters normally encountered in surveillance




         studies, the  concentration of oxidizing or reducing agents




         and potentially interfering metal ions are well below the




         limits causing interferences.  When present in sufficient




         concentration, metal  ions may produce a positive error,




         i.e., Hg  (II) and Cu  (II); may form colored complex ions




         having absorption bands in the region of color measurement.




5.   Apparatus




    5.1  Technicon AutoAnalyzer consisting of the following components:




         5.1.1  Sampler II.



         5.1.2  Manifold  (including Cu-Cd column).




         5.1.3  Colorimeter equipped with 50 mm tubular flow cell




                and 540 my filters.




         5.1.4  Range  expander.




         5.1.5  Recorder.




    5.2  Cadmium-copper reduction column    .




         5.2.1- Preparation:   Shake the 30  - 60 mesh av. diam. 0.5 mm




                cadmium turnings  (Note 1) with a solution of 2%  (wt/vol)
                                 182

-------
                                       (Nitrogen,  Nitrate-Nitrite)








       copper sulfate  pentahydrate  solution.   A weight  of




       solution equal  to  10  times the weight  of the cadmium




       is used.  The copper  sulfate-treated cadmium catalyst




       is then placed  in  a 8 mm x 50  mm pyrex tubing and is




       followed by av.  diam.  0.6 mm length 3.0 mm  copper




       rods made from  hydrogen treated copper wire (Note 2).




       The volume ratio of the cadmium bed to that of the




       copper should be about 3 - 1 to 4 - 1.  (See Figure 1).




       Pyrex wool, inserted  at the  lower end  of the reactor,




       is used to prevent the catalyst from dropping out of




       the reactor.  The  ends of the  reactor  are (fabricated




       to accommodate  the reactor into the system.  The sample




       enters the column  at  the copper granule-packed end.




       To minimize back pressure due to a vertical position




       or channelling  due to a horizontal position, the




       reductant tube  is  placed in  an up-flow 20  incline.




       Note 1 - Supplied  by  Technicon Corp.,  Ardsley, N.Y.




       Note 2 - Supplied  by  FM Scientific Corp.,  Avondale, Pa.




5.2.2  Regeneration:  HC1, diluted  1 to 4, is pumped through




       the NH.C1 line  for one minute, followed by  water for




       two minutes and then  2% copper sulfate solution  for five



       minutes.  For complete cleaning and coating, remove the




       column from the manifold. Using a small funnel  and a




       short plastic connecting tube, the acid water and copper
                        183

-------
                                                  (Nitrogen, Nitrate-Nitrite)








                sulfate solution are successively poured into the




                column and allowed to flow through by gravity.  The




                cadmium should ultimately acquire a moss-black




                appearance and the copper, a bright orange.




6.   Reagents




    6.1  Distilled water:  Because of possible contamination, this




         should be prepared by passage through an ion exchange column




         comprised of amixture 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.




    6.2  Color reagent:  To approximately 800 ml of distilled water,




         add, while stirring, 100 ml concentrated phosphoric acid,




         40 g sulfanilamide, and 2 g N-l naphthylethylenediamine




         dihydrochloride.  Stir until dissolved and dilute to one




         liter.  Store in brown bottle and keep in the dark when not




         in use.  This solution is stable for several months.




    6.3  Wash solution:  Use distilled water for unpreserved samples;




         samples preserved with hLSO., use 1 ml H-SO. per liter of




         wash water.




    6.4  Ammonium Chloride Solution  (8.5% NH.C1):  Dissolve 85 g of



         NH.C1 reagent grade Ammonium Chloride in distilled water and




         dilute to one liter with distilled water.  Add 1/2 ml Brij-
                                184

-------
                                             (Nitrogen,  Nitrate-Nitrite)



6.5  Stock nitrate solution:   Dissolve 7.218 g KNO  and  dilute

     to 1000 ml with distilled water.   Preserve with 2 ml of

     chloroform per liter.   Solution is stable for 6 months.

     1 ml = 1.0 mg NO -N.
                     o

6.6  Stock nitrite solution:   Dissolve 6.072 g KNO? and  dilute

     to 1000 ml with distilled water.   Solution is unstable;

     prepare as required.   1  ml = 1.0 mg NCL-N.

6.7  Standard nitrate solution:  Dilute 10.0 ml of stock nitrate

     solution to 1 liter.   1  ml = 0.01 mg NO_-N.  Preserve with

     2 ml of chloroform per liter.  Solution is stable for 6

     months.

6.8  Standard nitrite solution:  Dilute 10.0 ml of stock nitrite

     solution to 1 liter.   1  ml = 0.01 mg NCL-N.  Solution is

     unstable; prepare as  required.

6.9  Using either standard nitrate solution or standard nitrite

     solution, prepare the following standards in 100.0-ml

     volumetric flasks:

     Cone., mg NCL-N or NO -N/l        Standard Solution/100 ml

                0.0                               0
                0.05                              0.5
                0.10                              1.0
                0.20                              2.0
                0.50                              5.0
                1.00                             10.0
                2.00                             20.0
                4.00                             40.0
                6.00                             60.0
                            185

-------
                                                  (Nitrogen,  Nitrate-Nitrite)







         Note:  When the samples to be analyzed are saline waters,



                substitute Ocean Water (SOW)  (5) should be used for



                preparing the standards; otherwise, distilled water



                is used.  A tabulation of SOW composition follows:



         NaCl - 24.53 g/1       MgCl2 - 5.20 g/1      Na2S04  - 4.09 g/1



         CaCl2 - 1.16 g/1       KC1   - 0.70 g/1      NaHC03  - 0.20 g/1
         KBr   - 0.10 g/1       H3B03 ' -03 g/1      SrC12  " 0>03


         NaF   - 0.003 g/1



7.  Procedure



    7.1  Set up the manifold as shown in Figure 2.  Note that reductant



         column should be in 20 incline position with Cu at lower end.



    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 appropriate nitrate and/or nitrite standards in sampler



         in order of decreasing concentration of nitrogen.  Complete



         loading of sampler tray with unknown samples.



    7.4  Switch sample line to sampler and start analysis.



8.  Calculations



    8.1  Prepare appropriate standard curve or curves derived from



         processing NO, and/or N07 standard through manifold.  Compute
                      J          ^


         concentration of samples by comparing sample peak heights with



         standard curve.  Any sample whose computed concentration is



         less  than 10% of its immediate predecessor must be rerun.
                                186

-------
                                                  (Nitrogen,  Nitrate-Nitrite)
9.   Precision and Accuracy




    9.1  Precision and accuracy data are not available at this time.






                             References
1.  J.E.  O'Brien and J.  Fiore,  "Automation in Sanitary Chemistry -




    parts 1  2 Determination of Nitrates and Nitrites."  Wastes




    Engineering, 33, 128 $ 238 (1962).




2.  J.D.  Strickland, C.R.  Stearns, and F.A. Armstrong, "The Measure-




    ment of Upwelling and Subsequent Biological Processes by Means




    of the Technicon AutoAnalyzer and Associated Equipment."  Deep




    Sea Research 14, 381-389 (1967).




3.  "ASTM Manual on Industrial Water and Industrial Waste Water,"




    Method D 1254, page 465 (1966).




4.  Chemical Analyses for Water Quality Manual, Department of the




    Interior, FWPCA, R.A.  Taft Sanitary Engineering Center Training




    Program, Cincinnati, Ohio  45226 (January 1966).




5.  "ASTM Manual on Industrial Water and Industrial Waste Water,"




    Substitute Ocean Water, Table 1, page 418, 1966 edition.
                                187

-------
                  INDENTATIONS FOR
                SUPPORTING CATALYST
GLASS WOOL
Cd-TURNINGS
                                    Cu-FILINGS (FINE MESH)
            TILT COLUMN TO 20 POSTION
    FIGURE 1. CADMIUM-COPPER REDUCTION COLUMN
                (1 1/2 ACTUAL SIZE)
                           189

-------
                                      TO SAMPLE WASH
                                                              SAMPLER  2

t


WASTE


C






VS-3
0000 .
-3*







HO
MIXER




k


/ _WASTE
00000000
DOUBLE MIX
WASTE
^\
COLORIMETER
50mm TUBULAR f/c
540mji FILTERS


ER
~l
I 1
/.
1-
Cu

HO COLUMN

1
J


<




|DO
* *



T


















0
BLUE BLUE
R R
G 6
0 0
G G
BLUE BLUE
Y Y
Y Y

,/  / RATE:
ml/mm /

0.42
1.60 NaHCOa
0.80 AIR (
2.00 ACID-H20
0.42 COLOR REAGENT
2.00
1.60 SAMPLE t
1.20 8.5% NHiCL^
1.20 AIR

PROPORTIONING PUMP
RECORDER
* FROM C-3 TO SAMPLE LINE
mn x niB PHI YFTHVI rut
RANGE EXPLANDER
** SEE FIGURE 1. FOR DETAIL. COLUMN
   SHOULD BE IN 20 INCLINE POSITION
   WITH Cu AT LOWER END.
 FIGURE 2.  NITRATE-NITRITE  MANIFOLD

-------
                         NITROGEN, NITRITE









1.  Scope and Application




    1.1  This method is applicable to the determination of nitrite in




         surface waters, domestic and industrial wastes, and saline




         waters.




    1.2  The method is applicable in the range from 0.05 to 1.0 mg/1




         N02/N.









2.  Summary of Method




    2.1  The diazonium compound formed by diazotation of sulfanilamide




         by nitrite in water under acid conditions is coupled with




         N-(l-naphthyl)-ethenediamine to produce a reddish-purple color




         which is read in a spectrophotometer at 540 my.









3.  Sample Handling and Preservation




    3.1  Until more conclusive data is obtained, samples may be pre-




         served by addition of 40 mg HgCl2 per liter and stored at




         4C.








4.  Interferences




    4.1  There are very few known interferences at concentrations less




         than 1,000 times that of the nitrite; however, recent addition




         of strong oxidants or reductants to the samples will readily




         affect the nitrite concentrations.  High alkalinity (>600 mg/1)




         will give low results due to a shift in pH of the color reaction.
                                 193

-------
                                                    (.'Nitrogen, Nitrite)









5.  Apparatus




    5.1  Spectrophotometer equipped with 1.0 and 5.0 cm cuvettes




         for use at 540 mp.




    5.2  Nessler tubes, 50 ml or volumetric flasks, 50 ml.








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 concentrated hydrochloric acid, 5.0 g sulfanilamide




         and 0.5 g N-1-Naphthylethylenediamine dihydrochloride.




         Stir until dissolved.  Add 136 g of sodium acetate and




         again stir until dissolved.  Dilute to 500 ml with dis-




         tilled water.  This solution is stable for several weeks




         if stored in the dark.




    6.3  Nitrite-nitrogen stock solution, 1.0 ml = 0.10 mg N02-N.




         Dissolve 0.4926 g of dried anhydrous sodium nitrite, in




         distilled water and dilute to 1000 ml.  Preserve with 2-ml




         chloroform per liter.




    6.4  Nitrite-nitrogen standard solution, 1.0 ml = 0.001 mg NO--N.




         Dilute 10 ml of the stock solution to 1.0 liter.









 7.   Procedure



     7.1  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.
                                   194

-------
                                                (Nitrogen, Nitrite)



    7.2  Filter  the  sample  through  a  0.45 y 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.

    7.4  At the  same time prepare a series  of  standards in 50-ml

         Nessler tubes  as follows:

         ml of Standard Solution         Cone.,  When  Diluted  to

         1.0  ml  = 0.001 mg  NO -N         50 ml,  mg/1  of  NO  -N
                   0.0  (Blank)                     0.0
                   0.5                             0.01
                   1.0                             0.02
                   1.5                             0.03
                   2.0                             0.04
                   3.0                             0.06
                   4.0                             0.08
                   5.0                             0.10
                  10.0                             0.20

    7.5  Add 2.0  ml of  buffer-colored reagent 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 2.0.

    7.6  Read the color in the  spectrophotometer at 540 my  against

         the blank and  plot concentration of NO,,-N against optical

         density.



8.   Calculation

    8.1  Read the concentration of N02-N directly from  the curve.
                                 195

-------
                                                 (Nitrogen,  Nitrite)



    8.2  Calculate the concentration of NO -N in the sample in

         milligrams per  liter as follows:

         ND  N    /I - absorbance of sample x mg/1 standard x 50
           2~ '  ^   ~   absorbance of standard x ml sample

9.  Precision and Accuracy

    9.1  Precision and accuracy data are not available at this time.
                                   196

-------
                  NITROGEN, ORGANIC + AMMONIA



                  (Automated Phenolate Method)








1.  Scope and Application




    1.1  This automated method is applicable to surface and saline




         waters.   The applicable range is 1.0 to 10.0 mg N/l.




         Approximately 15 samples per hour can be analyzed.









2.  Summary of Method




    2.1  Organic nitrogen is determined by manually digesting  the




         sample with potassium persulfate and sulfuric acid to con-




         vert the organic nitrogen,  and any ammonia present, to ammonium




         sulfate.  Subsequently, the automated phenol-hypochlorite pro-




         cedure is used to measure the ammonia nitrogen.  Nitrate-




         nitrite nitrogen is not measured by this procedure.








3.  Sample Handling and Preservation




    3.1  Preservation by addition of 40 mg HgCl2 per liter and refrig-



         eration at 4C is necessary.









4.  Interferences




    4.1  No significant interferences.








5.  Apparatus




    5.1  Technicon AutoAnalyzer consisting of:
                               197

-------
                                                   (Nitrogen,  Organic
                                                      + Ammonia)
         5.1.1  Sampler I.

         5.1.2  Continuous Filter.

         5.1.3  Manifold.

         5.1.4  Proportioning Pump.

         5.1.5  Colorimeter equipped with 15 mm tubular flow cell

                and 650 mp filters.

         5.1.6  Recorder equipped with range expander.

    5.2  Hot plate.



6.  Reagents

    6.1  Distilled Water:  Special precaution must be taken to insure

         that distilled water is free of ammonia.   Such water is pre-

         pared 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.  Since organic

         contaminants 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 in-

         structions of the manufacturer.



         Note:  All glassware must be pre-rinsed with this ammonia-

         free water to prevent contamination.
                               198

-------
                                               (Nitrogen,  Organic
                                                  + Ammonia)
6.2  Sulfuric Acid:   As it readily absorbs ammonia,  special pre-

     caution must also be taken with respect to its  use.   Do not

     store bottles reserved for this determination in areas of

     potential ammonia contamination.

6.3  Potassium persulfate, low N (0.001%):  Certain  lots  of this

     reagent do not meet this specification for nitrogen  content.

     In order to insure this purity, dissolve 50 g of the reagent

     in 500 ml of distilled water at 60 to 70C.  Make alkaline

     with 10 ml of sodium hydroxide solution, 2.2M.   Bubble air

     that has been passed through a 10% sulfuric acid solution

     through a tube which has been drawn into a capillary into the

     solution while withdrawing air from the solution, which is

     contained in a suction flask, under reduced pressure.  Control

     the air flow so that a rather vigorous bubbling through the

     solution is maintained.  After 30 minutes of vigorous bubbling,

     cool the solution overnight in a refrigerator at about 4C.

     Filter the crop of crystals through a No. 40 Whatman filter

     paper previously washed with ammonia-free water.  Wash the

     crystals with ice-cold ammonia-free water.  Dry the  crystals

     at 60 to 70C and store in a tightly closed reagent  bottle.

6.3  Sulfuric acid solution:  Add slowly and with stirring 310

     ml of reagent grade, concentrated sulfuric acid to 600 ml of

     ammonia-free water.  Cool and dilute to 1,000 ml.

6.4  Phenol solution:  Dissolve 83 g of phenol in 500 ml  of ammonia-

     free water by stirring with a Teflon coated magnet for 10

     minutes.  Add 32 g NaOH and dilute to 1 liter.
                           199

-------
                                                   (Nitrogen, Organic
                                                      + Ammonia)
    6.5  Sodium hypochlorite solution:  Dilute 250 ml of bleach solution

         containing 5.25% NaOCl to 500 ml with ammonia-free water.

    6.6  Neutralizing solution:  Dissolve 6 g EDTA disodium salt and

         65 g of NaOH in 500 ml of distilled water.  Dilute to 1,000

         ml.

    6.7  Stock solution:  Dissolve 4.7168 g of ammonium sulfate analy-

         tical reagent in ammonia-free water and dilute to 1,000 ml.

         1.0 ml = 1.00 mg N.

    6.8  Standard solution:  Dilute 10.0 ml of stock solution to 100.0

         ml.   1 ml = 0.10 mg N.

         6.8.1  Using standard solution, prepare the following standards

                in 100-ml volumetric flasks:

                   mg N/l        ml Standard Solution/100 ml

                     0.0                    0
                     1.0                    1.0
                     2.0                    2.0
                     3.0                    3.0
                     4.0                    4.0
                     5.0                    5.0
                     6.0                    6.0
                     8.0                    8.0
                    10.0                   10.0



7.   Procedure

    7.1  Transfer a 25-ml sample of water to a 125-ml Erlenmeyer flask.

    7.2  Add 3 ml of sulfuric acid solution and evaporate on a hot

         plate to light fumes of SO,.  This step may require approximately

         one hour.  Close attention is not required of the sample;  how-

         ever, it should not be allowed to go to dryness.  Cool the

         sample.
                                200

-------
                                                   (Nitrogen,  Organic
                                                      + Ammonia)
    7.3  Add 1 ml of ammonia-free water and 1 g of potassium persul-

         fate, low N, and swirl the flask.

    7.4  Digest the sample on  the hot plate for 15 minutes.   Fumes

         of S0_ should begin coming off after 7 minutes.   The samples

         should become clear and transparent after this step, except

         in the presence of large amounts  of silica.   Cool the sample;

         dilute to 25 ml with  ammonium free water.  The sample is now

         ready for automatic analysis.

    7.5  Set up manifold as shown in Figure 1.

    7.6  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.

    7.7  Place distilled water wash tubes  in alternate openings in

         Sampler and set sample timing at  2.0 minutes.

    7.8  Arrange standards in  Sampler in order of decreasing concen-

         tration.  Complete loading of Sampler tray with unknown

         samples from 7.4

    7.9  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 concentration values.  Compute concentration

         of samples by comparing sample peak heights with standard curve.
                               201

-------
                                                   (Nitrogen, Organic
                                                      + Ammonia)
9.  Precision and Accuracy

    9.1  Precision and accuracy data are not available at this time.



                            References

1.  E. C. Julian and R. C. Kroner, "Determination of Organic Nitrogen

    in Water by Semi-Automatic Analysis," Automation in Analytical

    Chemistry, Technicon Symposia, 1966, Vol. 1, Mediad Inc., White

    Plains, N.Y. (1967), p 542.

2.  D. D. Van Slyke and A. J.  Hiller, Biol. Chem., 102, 499 (1933).
                                202

-------
    DOUBLE
    DELAY
    COIL
        (LM)
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UIICTC
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PR
P
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B
B
W
6
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W
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DPORTIONING PUI



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NaOH-EDTA
^ SAMPLE
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SODIUM CONTINUOUS FIL
^ HYPOCHLORITE >r
FILTERED SAMPLE
. WASTE
HP
SAMPLING TIME  2 MIN.
WASH TUBES - ONE
r
^P
TER
                                        COLORIMETER     RECORDER
                                        15mm TUBULAR  f/c
                                        650 mji FILTERS

                          FIGURE 1   ORGANIC NITROGEN & AMMONIA MANIFOLD

-------
                           OIL AND  GREASE








1.   Scope and Application




    1.1  This method includes  the measurement  of hexane  extractable




         matter from waters,  industrial  wastes,  and sewages.   It is




         applicable to the determination of relatively non-volatile




         hydrocarbons, animal  fats  and waxes,  grease and other types




         of greasy-oily matters.




    1.2  The method is not applicable to measurement of  light




         hydrocarbons that volatilize at temperatures below 80  C.




   1.3  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 (<3) and extracted




         with hexane using a Soxhlet extraction.  The solvent is




         evaporated from the separated extract and the residue




         weighed.








3.   Definitions




    3.1  The definition of grease and oil  is based on the




         procedure used.  The source of the oil and/or grease,




         the solvent used, and presence of extractable non-oily




         matter will influence the material measured and




         interpretation of results.
                                205

-------
                                                (Oil and Grease)








4.  Purity of Reagents




    4.1   Reagent grade hexane shall be used.








5.  Sampling and Storage




    5.1   A representative sample should be collected in a wide-




          mouth bottle marked at the 1 liter volume.  The initial




          step of acidification shall be carried out in the




          sample bottle.  The entire sample is used for the test.




    5.2   Because losses of grease will occur on sampling equip-




          ment, collection of a composite sample is impractical,




          and the examination of individual portions collected




          at prescribed time intervals must be used to obtain




          the average concentration over an extended period.








6.  Apparatus




    6.1   Extraction apparatus consisting of:




    6.1.1 Soxhlet Extractor, medium size (Corning No. 3740 or




          equivalent).




    6.1.2 Soxhlet thimbles, to fit in Soxhlet Extractor, 6.1.1.




    6.1.3 Blask, 125 ml (Corning No. 4100 or equivalent).




    6.1.4 Condenser, Allihn (bulb) type, to fit extractor.




    6.2   Vacuum pump, or other source of vacuum.




    6.3   Buchner funnel, 12 cm.
                                  206

-------
                                                  (Oil and Grease)








7.   Reagents




    7.1  Hydrochloric acid -  Cone.  (sp.  g 1.18).




    7.2  N-Hexane,  b.p.  69 C.




    7.3  Filter paper,  Whatman  No.  40,  11 cm.




    7.4  Muslin cloth discs,  11 cm.




    7.5  Diatomaceous -  silica  filter aid suspension,




         10 g/1 distilled water.




         Note 1 - Hyflo  Super-Gel  (Johns-Manvilie Corp.)




         or equivalent  is used  in  the preparation of the




         filter aid suspension.








8.   Procedure




    8.1  In the following procedure,  all steps  must be rigidly




         adhered to if consistent  results are  to be obtained.




    8.2  Acidify the 1  liter  sample  to pH <3,  which generally




         requires 5 ml  of cone. HC1.   Use of a pH sensitive




         paper is recommended when checking the pH of the sample.




    8.3  Prepare a  filter consisting of a muslin cloth disc




         overlaid with  filter paper.   Place the assembled filter




         in the Buchner funnel  and wet the filter, pressing down




         the  edges  to secure  a  seal.   Using a  vacuum,  add 100 ml




         of the filter aid suspension through  the filter  and then




         wash with  3-100 ml volumes  of distilled water.  Continue




         the  vacuum until no  more  water passes  through the filter.




    8.4  Filter the acidified sample under vacuum and again con-




         tinue the  vacuum until no more water  passes through the




         filter.
                                207

-------
                                            (Oil and Grease)








8.5  Remove the filter paper to a watch glass by means of




     forceps.   Add the material adhering to the edges of




     the muslin cloth disc.  Wipe the sides and bottom of the




     collecting vessel, the stirring rod, and the Buchner




     funnel with pieces of filter paper soaked in hexane.




     Care must be taken to remove all films due to .grease




     and to collect all solid material.  Add all pieces of




     filter paper to-the paper on the watch glass.  Roll




     the filter paper and the pieces of filter paper and




     fit into a paper extraction thimble.  Wipe the watch




     glass with a piece of filter paper soaked in hexane




     and place in the extraction thimble.




8.6  Dry the extraction thimble containing the filter paper




     in an oven at 103 C for exactly 30 minutes.  Fill the




     thimble with small glass beads or glass wool.




8.7  Weigh the extraction flask, add the hexane, and connect




     to the Soxhlet apparatus in which the extraction thimble




     has been placed.  Extract at the rate of 20 cycles per




     hour for four hours.   The four hours is timed from the




     first cycle.




8.8  Distill the solvent from the extraction flask in a




     water bath at 85 C.   Dry by placing the flask on a




     steam bath and draw air through the flask by means




     of an applied vacuum for 15 minutes.




8.9  Cool in a desiccator for 30 minutes and weigh.
                            208

-------
                                                 (Oil and Grease)
 9.   Calculation

     9.1  mg/1 .total grease = mg increase in weight of flask x 1,000
                                            ml sample
10.   Precision and Accuracy

     10.1  Precision and accuracy data are not available.
                                  209

-------
                ORGANIC CARBON,  TOTAL AND DISSOLVED






1.  Scope and Application




    1.1  This method includes the measurement of organic carbon in




         surface waters,  domestic and industrial wastes, and saline




         waters.  Exclusions are noted under Definitions and




         Interferences.




    1.2  The method is applicable to measurement in the range of 1




         to 150 mg/liter.




2.  Summary of Method




    2.1  A micro sample of the wastewater to be analyzed is injected




         into a catalytic combustion tube which is  enclosed by an




         electric furnace thermostated at 950C.  The water is




         vaporized and the carbonaceous material is oxidized to




         carbon dioxide (C02) and steam in a carrier stream of pure




         oxygen.  The oxygen flow carries the steam and C07 out of




         the furnace where the steam is condensed and the condensate




         removed.  The C02, oxygen,  and remaining water vapor enter




         an infrared analyzer sensitized to provide a measure of CO^.




         The amount of CO- present is directly proportional to the




         concentration of carbonaceous material in the injected




         sample.




3.  Definitions




    3.1  The carbonaceous analyzer measures all of the carbon in a




         sample after injection into the combustion tube.  Because
                                211

-------
                                                    (Organic Carbon)








     of various properties of carbon-containing compounds  in




     liquid samples, preliminary treatment of the sample prior




     to injection dictates the definition of the carbon as it




     is measured.




     Forms of carbon that are measured by the combustion-




     infrared 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
                            212

-------
                                                        (Organic Carbon)








         should be discounted in  the  final  calculation or  removed



         prior to analysis.   The  manner  of  preliminary treatment




         therefore defines  the types  of  carbon which are measured.




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 cubitainers is permissible




         if it is established that the containers  do not contribute




         contaminating organics to the samples (Note 1).




         Note 1 - A brief study performed in the AQC 'Laboratory




         indicated that distilled water  stored in  new, one quart




         cubitainers 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 minimum.  Also, samples  should




         be kept cool (4C) and protected from sunlight  and atmospheric




         oxygen.




    4.3  In instances where analysis  cannot be performed within two




         hours (2 hours) from time of sampling, it is recommended




         that the sample be acidified (pH = 2) with HC1.




5.   Interferences




    5.1  Carbonate and bicarbonate carbon represent an  interference




         under the terms of this  test and must be  removed  or accounted
                                213

-------
                                                       (Organic Carbon)








         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 microliter type syringe.  The needle




         openings of the syringe limit the maximum size of particles




         which may be included in the sample.  (Cf 6.3)




6.   Apparatus




    6.1  Apparatus for blending or homogenizing samples:




         Generally, a Waring-type blender is satisfactory.




    6.2  Apparatus for total and dissolved organic carbon:




         6.2.1  Dow-Beckman Carbonaceous Analyzer, (single




                channel) or




         6.2.2'  Dow Beckman Carbonaceous Analyzer Model No. 915




                (dual channel).




    6.3  Hypodermic syringe, 0-50 yl, needle opening of




         approximately 150 microns; Hamilton No. 705 N or equivalent



         is satisfactory.




         6.3.1  Hamilton No. 750 N, 0-500 yl has a needle opening




                of approximately 400 microns and may be used for




                samples containing large particulates.



7.  Reagents and Materials




    7.1  Distilled water used  in preparation of standards and for




         dilution of samples should be ultra pure to reduce the




         size of the blank.  Carbon dioxide-free, double distilled
                                214

-------
                                                    (Organic Carbon)



     water is recommended.   Ion exchanged waters are not recom-

     mended because of the  possibility of contamination with

     organic materials from the resins.

7.2  Potassium Hydrogen Phthalate,  stock solution,  1000 mg carbon/

     liter:   Dissolve 0.2128 gof potassium hydrogen phthalate

     (Primary Standard Grade)  in double  distilled water and dilute

     to 100.0 ml.

     Note:  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 with double dis-

     tilled water as follows:

            ml of Stock Solution          Standard
             Diluted to 100 ml           mg C/liter

                    1.0                      10
                    2.0                      20
                    3.0                      30
                    4.0                      40
                    5.0                      50
                    6.0                      60
                    8.0                      80
                   10.0                     100

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  double distilled water.

7.5  Carbonate-bicarbonate, standard solution:  Prepare a series

     of standards similar to 7.3.

7.6  Blank solution:  Use the  same distilled water (or  similar

     quality water) used for the preparation of the standard

     solutions.
                             215

-------
                                                   (Organic Carbon)








7.7  Packing for total carbon tube.  Dissolve 20 g of




     Co(N0_)-.6H-0 (cobalt nitrate hexahydrate)  in 50 ml of




     distilled water.  Add this solution to 15 grams of long-




     fiber asbestos in a porcelain evaporating dish.  Mix and




     evaporate to dryness on a steam bath.   Place the dish in




     a cold muffle furnace and bring to a temperature of 950C.




     After one to two hours at this temperature, remove the




     dish and allow to cool.  Break up any large lumps and mix




     adequately but not excessively.




     With the combustion tube held in a vertical position,




     taper joint up, put about 1/2" of untreated asbestos in




     the tube first, then transfer, in small amounts, approx-




     imately one gram of catalyst into the tube with forceps or




     tweezers.   As it is added, tap or push the material gently




     with a 1/4" glass rod.  Do not force the packing.  The




     weight of the rod itself is sufficient to compress the




     material.   When completed, the length of the packing should




     be about five or six centimeters.




     Test the packed tube by measuring the flow rate of gas




     through it at room temperature, and then at 950C.  The




     rate should not drop more than 20%.




7.8  Packing for carbonate tube, (dual channel instrument).




     Place a small wad of quartz wool or asbestos near the exit




     end of the carbonate evolution tube.  From the entrance
                            216

-------
                                                       (Organic Carbon)








         end add  6-12 mesh quartz chips,  allowing these to




         collect against the wad to a length of 10 cm.   Pour an




         excess of 85 percent phosphoric acid into the  tube while




         holding it vertically,  and allow  the excess to drain out.




8.   Instrument Adjustment




    8.1  Turn on the infrared analyzer,  recorder,  and tube furnaces,




         setting the total carbon furnace  at 950C and  the carbonate




         furnace at 175C.  Allow a warm-up time of at  least 2 hr.




         for attainment of stable operation; in daily use the




         analyzer can be left on continuously.   Adjust  the oxygen




         flow rate to 80 to 100  ml/min through the total carbon




         tube.  With the recorder set at the 5-mv range, adjust the




         amplifier gain so that  a 20-yl  sample of the 100 mg/liter




         carbon standard gives a peak height of approximately half




         the recorder scale (see 7.3).  At this setting the noise




         level should be less than 0.5 percent of full  scale.  If the




         noise level is higher,  the analyzer or the recorder may re-




         quire servicing.




    8.2  Immediately prior to carrying out calibrations or analyses,




         inject several portions of the appropriate 100 mg/liter




         standard (see 7.2) into the tube  to be used, until constant




         readings are obtained.
                               217

-------
                                                        (Organic Carbon)








9.  Calibration - Dual Channel Instrument




    9.1  Successively introduce 20 yl of each phthalate standard




         into the total carbon tube and read the height of the




         corresponding peak.  Between injections allow the recorder




         pen to return to its base line.  The actual injection




         technique is as follows:  Rinse the syringe several times




         with the solution to be analyzed, fill, and adjust to 20 yl.




         Wipe off the excess with soft paper tissue, taking care that




         no lint adheres to the needle.  Remove the plug from the




         syringe holder, insert the sample syringe, and inject the




         sample into the combustion tube with a single, rapid move-




         ment of the index finger.  Leave the syringe in the holder




         until the flow rate returns to normal, then replace it with




         the plug.  Run duplicate determinations on each solution and




         on a water blank.




    9.2  Correct standards  for blank correction as follows:  Standard




         peak height minus blank peak height = correct peak height




         in mm.  Prepare a  standard curve of total carbon versus peak




         height.




    9.3  In the  same way, prepare a series of diluted carbonate




         standards  containing  20, 40, 60, 80, and  100 mg of inorganic




         carbon  per liter.   Turn the four-way valve of the apparatus




         to direct  the  gas  flow  through the  low temperature tube and
                                 218

-------
                                                        (Organic Carbon)








          to the analyzer.   Adjust  the flow rate to 80 to 100 ml/min




          and allow the baseline  to become stabilized.  Successively




          introduce 20 yl  of each standard and a water blank in




          duplicate into the low  temperature tube and read the peak




          heights as previously described.




     9.4  Prepare a standard curve of inorganic carbon versus peak




          height applying the correction as noted in 9.2.




10.   Procedure - Dual Channel Instrument




    10.1  Mix or blend each sample thoroughly and carry out any




          appropriate dilution to bring the carbon content within the




          range of the standard curve.




    10.2  Following the technique described in 9.1 and 9.3, inject




          20-yl samples successively (in duplicate) into each tube




          and read the peak heights corresponding to total carbon




          and inorganic (carbonate) carbon.  From the appropriate




          calibration curve and each peak height observed, read the




          corresponding carbon concentration in mg/liter.




    10.3  Subtract the inorganic  carbon value from the total carbon




          value.  The difference  thus obtained is operationally




          defined as Total Organic Carbon.




    10.4  Filter a 100 ml aliquot through a pre-rinsed 0.45 y pore




          size filter.  Repeat sample injection as in 10.2.
                                219

-------
                                                        (Organic Carbon)








    10.5  Subtract the dissolved inorganic carbon value from the




          dissolved carbon value.  The difference thus obtained




          is operationally defined as Dissolved Organic Carbon.




11.  Calibration - Single Channel Instrument




    11.1  Standardize the instrument according to directions given




          in 9.1 and 9.2.




12.  Procedure - Single Channel Instrument




    12.1  Transfer a representative aliquot of about 10 - 15 ml to




          a 30 ml beaker, add 2 or more drops of concentrated HC1




          until the pH is reduced to = 2 and purge with C0_-free




          nitrogen gas for about 5-10 minutes.   (Do not use




          plastic tubing).  Place the beaker on a magnetic stirrer




          and while stirring withdraw a 20 yl sample.  Inject the




          sample as in 9.1.




    12.2  Obtain concentration directly from standard curve.  The




          carbon thus measured is operationally defined as Total




          Organic Carbon.




    12.3  Filter a 100-ml aliquot through a pre-rinsed 0.45 p pore




          size filter and proceed as in 12.1.




    12.4  Obtain concentration directly from standard curve.  The




          carbon thus measured is operationally defined as Dissolved




          Organic Carbon.
                                 220

-------
                                                        (Organic Carbon)
13.   Precision and Accuracy



     13.1  The precision of this method as determined by ASTM is



           expressed as follows:



           S  = 0.032 x + 0.03 where
            Li



           ST  = single laboratory precision and
            Lt


           x  = concentration of carbon in mg/1
                                 221

-------
                        PHOSPHORUS, ALL  FORMS




                       (Single  Reagent Method)









1.   Scope and Application




    1.1  These methods  cover  the  determination  of  specified  forms




         of phosphorus  in  surface waters,  domestic and  industrial




         wastes,  and  saline waters.   They  may be applicable  to




         sediment-type  samples, sludges, algal  blooms,  etc., but




         sufficient data is not available  at this  time  to  warrant




         such usage when measurements for  phosphorus  content are




         required.




    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 phos-




         phorus given in Figure 1 may be determined.  These  forms  are,




         in turn, defined  in  Table  1.




         1.2.1  Except  for in-depth and  detailed studies,  the  most




                commonly measured forms  are  phosphorus  and dissolved




                phosphorus, and orthophosphate  and dissolved ortho-




                phosphate. Hydrolyzable phosphorus is  normally




                found only in sewage-type  samples  and insoluble




                forms of phosphorus,  as  noted,  are determined  by




                calculation.




    1.3  The methods  are usable in  the 0.01  to  0.5 mg/1 P  range.
                                 223

-------
to
             Residue
                                   SAMPLE
                                                  Total Sample (No Filtration)
                                                       V
                                                              Direct
                                                              Colorimetry
V
                         Hydrolysis
                                                      Orthophosphate
                       Hydrolyzable 
                       Orthophosphate
                                           Filter (through 0.45 u membrane filter)
                                     N/
Filtrate
\
Direct
Colorimetry
/
Dissolved
Orthophosphate

\
/
H2S04
Hydrolysis fT
Colorimetry
Diss . Hydrolyzable
 Orthophosphate

Persulfate
Digestion 
.Colorimetry
Dissolved
Phosphorus
                                               \
Persulfate
Digestion
Co lorimptry
                         Phosphorus
                        Figure  1.   Analytical  Scheme for Differentiation of Phosphorus Forms.

-------
                                                     (Phosphorus)








2.  Summary of Method




    2.1  Ammonium molybdate and potassium antimonyl  tartrate react




         in an acid medium with dilute solutions  of phosphorus to




         form an antimony-phosphate-molybdate complex.   This com-




         plex 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  sulfuric-




         acid-hydrolysis.  Organic phosphorus compounds  may be




         converted to the orthophosphate form by  persulfate di-




         gestion.







3.  Definitions




    3.1  The various forms of phosphorus are defined in  Table 1.








4.  Sample Handling and  Preservation




    4.1  If benthic deposits are present in the area being sampled,




         great care should be taken not to include  these deposits.




    4.2  Sample containers may be of plastic material, such as




         cubitainers, or of Pyrex glass.




    4.3  If the analysis cannot be performed the  same day of




         collection, the sample should be preserved by the ad-




         dition of 40 mg HgCl- per liter and refrigeration at




         4 C.
                                 225

-------
                                                (Phosphorus)







                              TABLE 1



                      PHOSPHORUS TERMINOLOGY







1.   Phosphorus (P) - all of the phosphorus present in the sample,



    regardless of form, as measured by the persulfate digestion



    procedure.



    a.   Orthophosphate (P, ortho) - inorganic phosphorus



        [(PO.)  ]  in the sample as measured by the direct color-



        imetric analysis procedure.



    b.   Hydrolyzable Phosphorus (P, hydro) - phosphorus in the



        sample as  measured by the sulfuric acid hydrolysis pro-



        cedure, and minus pre-determined orthophosphates.



        This hydrolyzable phosphorus includes polyphosphates


               -4         -5
        [(P-O-)  , (P_0 _)  , etc.] + some organic phosphorus.



    c.   Organic Phosphorus (P, org) - phosphorus (inorganic +



        oxidizable organic) in the sample as measured by the



        persulfate digestion procedure, and minus hydrolyzable



        phosphorus and orthophosphate.



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.



    a.   Dissolved Orthophosphate  (P-D, ortho) - as measured by



        the direct colorimetric analysis procedure.



    b.   Dissolved Hydrolyzable Phosphorus (P-D, hydro) - as



        measured by the sulfuric  acid hydrolysis procedure and



        minus pre-determined dissolved orthophosphates.
                                 226

-------
                                                         (Phosphorus)








                           TABLE 1  (Continued)









    c.   Dissolved Organic Phosphorus (P-D,  org)  - as measured




        by the persulfate digestion procedure,  and minus dis-




        solved hydrolyzable phosphorus and  orthophosphate.




3.   The following forms,  when sufficient amounts of phosphorus are




    present in the sample to warrant such consideration, may be




    calculated:




    a.   Insoluble Phosphorus (P-I)  = (P) -  (P-D).




        (1)  Insoluble orthophosphate (P-I, ortho) = (P, ortho) -




             (P-D, ortho).




        (2)  Insoluble Hydrolyzable Phosphorus  (P-I, hydro) =




             (P, hydro) - (P-D, hydro).




        (3)  Insoluble Organic Phosphorus (P-I,  org) = (P,  org) -




             (P-D, org).




4.   All phosphorus forms  shall be reported as P, mg/1.









5.   Interferences




    5.1  It is reported    that no interference is caused by copper,




         iron, or silicate at concentrations many times greater than  .




         their greatest reported concentration in sea water.  However,




         high iron concentrations can cause precipitation of phosphorus




         through the formation of clumps in the bottom of the sample.




    5.2  The salt error for samples ranging from 5 to 20 percent salt




         content was found to be less than 1 percent    .




    5.3  Arsenate, in concentrations greater than found in sea water,




         does not interfere
                                   227

-------
                                                 (Phosphorus)






6.   Apparatus


    6.1  Photometer - A spectrophotometer or filter photometer suitable


         for measurements at 880 my, and providing a light path of 1


         inch (2.54 cm) or longer, should be used.


    6.2  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 dis-


         tilled water and treated with all the reagents to remove the


         last traces of phosphorus that might be adsorbed on the glass-


         ware.  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.





7.   Reagents


    7.1  Sulfuric acid solution, 5N:  Dilute 70 ml of cone.  H SO  with


         distilled water to 500 ml.


    7.2  Potassium antimonyl tartrate solution:  Weigh 1.3715  g


         K(SbO)C4H 0 .1/2 HO, dissolve in 400 ml distilled water



         in 500 ml volumetric flask, dilute to volume.  Store in


         glass-stoppered bottle.

                                                                  4
    7.3  Ammonium molybdate solution:  Dissolve 20 g (NH.)6Mo_02..   H_0


         in 500 ml distilled water.  Store in a plastic bottle at 4 C.
                                 228

-------
                                            (Phosphorus)








7.4  Ascorbic acid, 0.1M:   Dissolve 1.76 g of ascorbic acid in




     100 ml of distilled water.   The solution is stable for




     about a week if stored at 4 C.




7.5  Combined reagent:   Mix the  above reagents in the following




     proportions for 100 ml of the mixed reagent:  50 ml  of




     5N H-SQ., 5 ml of potassium antimonyl tartrate solution, 15




     ml of ammonium molybdate solution,  and 30 ml of ascorbic




     acid solution.  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 it stand for  a few




     minutes until the  turbidity disappears before preceding.



     The reagent is stable for one week  if stored at 4 C.




7.6  Strong-acid solution:  Slowly add 310 ml cone. H SO. to




     600 ml distilled water.   When cool, dilute to 1 liter.




7.7  Ammonium persulfate.




7.8  Stock Solution:   Dissolve in distilled water 0.2197  g of




     potassium dihydrogen  phosphate, KH^PO., which has been dried




     in an oven at 105 C.  Dilute the solution to 1,000  ml;




     1.00 ml equals 0.05 mg P.




7.9  Standard Solution: Dilute  10.0 ml  of stock phosphorus




     solution to 1,000  ml  with distilled water; 1.00 ml equals




     0.5 yg P.




     7.9.1  Using standard solution, prepare the following
                             229

-------
                                                    (Phosphorus)
             standards in 50.0-ml volumetric flasks:

                ml of Standard Solution    Cone., mg/1
0
1.0
3.0
5.0
10.0
20.0
30.0
40.0
50.0
0.00
0.01
0.03
0.05
0.10
0.20
0.30
0.40
0.50
8.   Procedure

    8.1  Phosphorus

         8.1.1  Add 1 ml of strong-acid solution to a 50 ml
      )
                sample in a 125-ml Erlenmeyer flask.

         8.1.2  Add 0.4 gram 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 al-

                low sample to go to dryness.  Alternatively,

                heat for 30 minutes in an autoclave at 121 C

                (15-20 psi).

         8.L.4  Add phenolphthalein and adjust sample to pink

                with IN NaOH.  Bring back to colorless with one

                drop strong-acid solution.  Cool and dilute the

                sample to 50 ml.

         8.1.5  Determine phosphorus as outlined in 8.3.2 Ortho-

                phosphate .

    8.2  Hydrolyzable Phosphorus

         8.2.1  Add 1 ml of strong-acid solution to a 50-ml


                                 230

-------
                                                     (Phosphorus)








                sample  in  a  125-ml  Erlenmeyer  Flask.




         8.2.2   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 auto-




                clave at 121 C (15-20  psi).




         8.2.3   Add phenolphthalein and adjust sample  to pink




                with  1  N NaOH.  Bring back to  colorless with one




                drop  strong-acid solutions.  Cool and  dilute the




                sample  to  50 ml.




         8.2.4   The sample is now ready for  determination  of




                phosphorus as outlined  in  8-3.2 Orthophosphate.




    8.3  Orthophosphate




         8.3.1   Add 1 drop of phenolphthalein  indicator to the




                50.0  ml sample. If a red  color develops,  add




                strong-acid  solution drop-wise to just discharge




                the color.




         8.3.2   Add 8.0 ml of combined  reagent 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 880  my with a spectro-




                photometer,  using the reagent  blank as the reference




                solution.




9.  Calculation




    9.1  Prepare standard  curve by  plotting absorbance values  of




         standards as ordinates and the corresponding phosphorus




         concentrations as abscissas.
                                 231

-------
                                                       (Phosphorus)









          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 cali-




                 bration curve.




     9.2  Obtain concentration value of sample directly from prepared




          standard curve.  Report results as P, mg/1.








10.   Precision and Accuracy




     10.1  In eight laboratories involving 13 analysts, using a




          variety of natural water samples, both salt and fresh,




          the standard deviation at a concentration of 0.23mg P/l




          was  0.004 (AQC Laboratory).




     10.2  Under the same conditions, recovery was 101% (AQC Laboratory)










                                References
 1.   J. Murphy and J. Riley, "A Modified Single Solution Method




     for the Determination of Phosphate in Natural Waters."




     Anal. Chim. Acta., 27, 31 (1962).




 2.   M. Gales, Jr., E. Julian, and R. Kroner, "Method for




     Quantitative Determination of Total Phosphorus in Water."




     Jour AWWA, 58, No. 10, 1363 (1966).
                                   232

-------
                       PHOSPHORUS,  ALL FORMS




                 (Automated Single  Reagent  Method)









1.   Scope and Application




    1.1  These methods  cover the determination of specified forms




         of phosphorus  in surface waters, domestic and industrial




         wastes,  and saline waters.   They may be applicable to




         sediment-type  samples,  sludges, algal blooms,  etc., but




         sufficient data is not  available at this time to warrant




         such usage when measurements for phosphorus  content are




         required.




    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 phos-




         phorus given in Figure  1 may be determined.   These forms  are,




         in turn,  defined in Table  1.




         1.2.1  Except  for in-depth and detailed studies, the most




                commonly measured forms  are phosphorus and dissolved




                phosphorus, and  orthophosphate and dissolved ortho-




                phosphate.   Hydrolyzable phosphorus is normally




                found only in sewage-type samples and insoluble




                forms of phosphorus,  as  noted, are determined by




                calculation.




    1.3  The methods are usable  in  the 0.01 to 1.0 mg P/l range.




         Approximately  20 samples per hour  can be analyzed.
                                233

-------
to
co
                                                     Total  Sample  (No  Filtration)
                                    \/
                                                                                  \/
                                                               Direct

                                                               Colorimetry
                           Hydrolysis
                       N/ Colorimetrv
                                                       Orthophosphate
                        Hydrolyzable 
                         Orthophosphate
                                           Filter  (through  0.45 u membrane  filter)
                                      Direct
                                      Colorimetry
                                                     \/
   Hydrolysis
   Colorimetry
                               Dissolved
                             Orthophosphate
    Persulfate

    Digestion 
 \/ Colorimetry
Diss. Hydrolyzable
 Orthophosphate
Dissolved
Phosphorus
                             Persulfate
                             Digestion
                          \1/ Colorimetrv
                           Phosphorus
                    Figure 1.  Analytical Scheme for Differentiation of Phosphorus Forms.

-------
                                                         (Phosphorus)







2.   Summary of Method



    2.1  Ammonium molybdate  and potassium antimonyl  tartrate  react



         in an acid medium with dilute  solutions  of  phosphorus  to



         form an antimony-phosphate-molybdate  complex.   This  com-



         plex 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 sulfuric-



         acid-hydrolysis. Organic phosphorus  compounds  may be  con-



         verted to the orthophosphate form by  manual persulfate


                  (2)
         digestion   .  The  developed  color is measured  automatically



         on the AutoAnalyzer.







3.   Definitions



    3.1.  The various forms of phosphorus are defined in  Table 1.







4.   Sample Handling and Preservation



    4.1  If benthic deposits are present in the area being sampled,



         great care should be taken not to include these deposits.



    4.2  Sample containers may be of plastic material, such as



         cubitainers, or of Pyrex glass.



    4.3  If the analysis cannot be performed the same day of collection,



         the sample should be preserved by the addition of 40 mg HgCl2



         per liter and refrigeration at 4C.
                                235

-------
                                                         (Phosphorus)








                             TABLE 1




                     PHOSPHORUS TERMINOLOGY








1.   Phosphorus (P) - all of the phosphorus present in the sample




    regardless of form, as measured by the persulfate digestion




    procedure.




    a.   Orthophosphate (P, ortho) - inorganic phosphorus




        [(PO.)  ] in the sample as measured by the direct color-




        imetric analysis procedure.




    b.   Hydrolyzable Phosphorus (P, hydro) - phosphorus in the




        sample as measured by the sulfuric acid hydrolysis pro-




        cedure, and minus pre-determined orthophosphates.  This




        hydrolyzable phosphorus includes polyphosphates




        [(P 0_)~ , (PjO n)~ , etc.] + some organic phosphorus.




    c.   Organic Phosphorus (P, org) - phosphorus (inorganic +




        oxidizable organic) in the sample as measured by the




        persulfate digestion procedure, and minus hydrolyzable




        phosphorus and orthophosphate.




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.




    a.   Dissolved Orthophosphate (P-D, ortho) - as measured by the




        direct colorimetric analysis procedure.
                                 236

-------
                                                         (Phosphorus)








    b.   Dissolved Hydrolyzable  Phosphorus  (P-D,  hydro)  -  as




        measured by the  sulfuric acid  hydrolysis procedure and




        minus  pre-determined dissolved orthophosphates.




    c.   Dissolved Organic Phosphorus  (P-D,  org)  - as  measured




        by the persulfate digestion procedure,  and minus  dissolved




        hydrolyzable phosphorus and orthophosphate.




3.   The following forms, when sufficient  amounts of phosphorus are




    present in the sample to warrant such  consideration,  may be




    calculated:




    a.   Insoluble Phosphorus (P-I)  =  (P)  -  (P-D).




        (1)  Insoluble orthophosphate  (P-I, ortho) =  (P,  ortho) -




             (P-D, ortho).




        (2)  Insoluble Hydrolyzable Phosphorus  (P-I,  hydro)  =




             (P, hydro)  - (P-D, hydro).




        (3)  Insoluble Organic  Phosphorus  (P-I,  org)  =  (P, org) -




             (P-D, org).




4.   All phosphorus forms shall  be reported as P, mg/1.








5.   Interferences




    5.1  It is reported    that no interference is caused by copper,




         iron, or silicate at concentrations many times greater than




         their greatest reported concentration in sea water.  However,




         high iron concentrations can  cause precipitation of phosphorus




         through the formation  of clumps  in the bottom of the sample.




    5.2  The salt error for samples ranging from 5 to 20 percent salt




         content was found to be less  than 1 percent    .
                                237

-------
                                                         (Phosphorus)
    5.3  Arsenate, in concentrations greater than found in sea water,




         does not interfere   .
6.  Apparatus




    6.1  Technicon AutoAnalyzer consisting of:




         6.1.1  Sampler I




         6.1.2  Manifold




         6.1.3  Proportioning Pump




         6.1.4  Heating Bath, 50C




         6.1.5  Colorimeter equipped with 50 mm tubular flow cell  and




                650 my filters




         6.1.6  Recorder




    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 phos-




         phorus 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.








7.  Reagents




    7.1  Sulfuric acid solution, 5N:  Dilute 70 ml of cone. H SO  with




         distilled water to 500 ml.
                                238

-------
                                                      (Phosphorus)





7.2  Potassium antimonyl  tartrate solution:   Weigh 0.3 g


     K(SbO)C4H.O  1/2 HO,  dissolve in 50 ml  distilled water


     in 100 ml volumetric flask,  dilute to volume.  Store in


     glass-stoppered bottle.

                                                             4
7.3  Ammonium molybdate solution:  Dissolve 4 g (NH.) ..Mo-O^..  H..O


     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 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 H?S04, 5 ml  of potassium antimonyl tartrate solution,


     15 ml of ammonium molybdate solution, and 30 ml of ascorbic


     acid solution.   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  it stand for a few


     minutes until the turbidity disappears before proceeding.


     This volume is  sufficient for 4 hours operation.   Since the


     stability of this solution is limited,  it must be freshly


     prepared for each run.


7.6  Strong-acid solution:   Slowly add 310 ml cone. H-SO. to


     600 ml distilled water.   When cool, dilute to 1 liter.


7.7  Ammonium persulfate.
                            239

-------
                                                  (Phosphorus)








7. 8  Wash water:  Add 40 ml of sulfuric acid solution to 1 liter




      of distilled water and dilute to 2 liters.   (Not to be used




      when only orthophosphate is being determined.)




7. 9  Stock Solution:  Dissolve 0.4393 g of pre-dried KH PQ  in




      distilled water and dilute to 1 liter.  1 ml =  0.1 mg P.




7.10  Standard Solution A:  Dilute 100 ml of stock solution to  1




      liter.  1 ml = 0.01 mg P.




7.11  Standard Solution B:  Dilute 100 ml of standard solution  A




      to 1 liter.  1 ml = 0.001 mg P.




7.12  Prepare a series of standards by diluting suitable volumes




      of standard solutions A and B to 100.0 ml with  distilled




      water.  The following dilutions are suggested:

ml




ml





of Standard Solution B
0.0
2.0
5.0
10.0
of Standard Solution A
2.0
5.0
8.0
10.0
Cone . ,
mg P/l
0.00
0.02
0.05
0.10

0.20
0.50
0.80
1.00
      Note:  When the samples to be analyzed are saline  waters,




      Substitue Ocean Water (SOW) should be used for preparing




      the standards; otherwise, distilled water is  used.   A




      tabulation of SOW composition follows:




      NaCl  -  24.53g/l     MgCl2  -  5.20g/l     Na2S04  -  4.09g/l




      CaCl2 -   1.16g/l     KC1    -  0.70g/l     NaHC03  -  0.20g/l





      KBr   -   0.10g/l     H3B03  -  0.03g/l     SrCl2    -  0.03g/l




      NaF   -   0.003g/l




                            240

-------
                                                         (Phosphorus)








8.  Procedure




    8.1  Phosphorus




         8.1.1  Add 1 ml of strong-acid solution to a 50 ml sample in




                a 125-ml Erlenmeyer flask.




         8.1.2  Add 0.4 gram 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.  Alter-




                natively, heat for 30 minutes in an autoclave at 121C




                (15-20 psi).                            




         8.1.4  Cool and dilute the sample to 50 ml.




         8.1.5  Determine phosphorus as outlined in 8.3 Orthophosphate.




    8.2  Hydrolyzable Phosphorus




         8.2.1  Add 1 ml of strong-acid solution to a 50-ml sample in a




                125-ml Erlenmeyer Flask.




         8.2.2  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).




         8.2.3  Cool and dilute the sample to 50.0 ml.




         8.2.4  The sample is now ready for determination of phosphorus




                as outlined in 8.3 Orthophosphate.




    8.3  Orthophosphate




         8.3.1  Set up manifold as shown in Figure 1.
                                 241

-------
                                                          (Phosphorus)








          8.3.2  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.




          8.3.3  Place wash water tubes (see 7.8) in Sampler, in sets




                 of 2, leaving every third position vacant.  Set sample




                 timing at 1.0 minutes.




          8.3.4  Place standards in Sampler in order of decreasing




                 concentration.  Complete filling of sampler tray with




                 unknown samples.




          8.3.5  Switch sample line from distilled water to Sampler and




                 begin analysis.








 9.  Calculation




     9.1  Prepare 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 ajid Accuracy




    10.1  In a single laboratory, using surface water samples at




          concentrations of .04, 0.19, 0.35, and 0.84 mg P/l, standard




          deviations were 0.005, 0.000, 0.003, and 0.000, respectively




          (AQC Laboratory).
                                 242

-------
                                                         (Phosphorus)








    10.2  In a single laboratory,  using surface water samples  at




          concentrations  of 0.07  and 0.76 mg P/l,  recoveries were




          99% and 100%,  respectively (AQC Laboratory).








                            References
1.   J.  Murphy and J.  Riley,  "A Modified Single Solution Method for the




    Determination of Phosphate in Natural Waters."  Anal.  Chim.  Acta.,




    27_, 31 (1962).




2.   M.  Gales, Jr., E.  Julian,  and R.  Kroner,  "Method for Quantitative




    Determination of Total Phosphorus in Water."  Jour AWWA,  58, No.  10,




    1363 (1966).
                                243

-------
to
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1.20 ^DISTILLED WATER
0.42 ^MIXED REAGENT
2.00, WASTE
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RECORDER SAMPLING TIME: 1.0 M
                   650 mjl FILTERS
                             FIGURE 1. PHOSPHORUS SINGLE REAGENT MANIFOLD

-------
                      PHOSPHORUS, ALL  FORMS




               (Automated Stannous  Chloride  Method)









1.   Scope and Application




    1.1  These methods cover  the determination  of  specified  forms




         of phosphorus in surface waters,  domestic and  industrial




         wastes.   They may be applicable to  sediment-type samples,




         sludges,  algal blooms, etc.,  but  sufficient  data is not




         available at  this time to  warrant such usage when measure-




         ments for phosphorus content  are  required.




    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 phos-




         phorus given  in  Figure 1 may  be determined.  These  forms are,




         in turn,  defined in  Table  1.




         1.2.1 Except for in-depth and detailed studies, the  most




               commonly  measured forms are  phosphorus  and dissolved




               phosphorus, and orthophosphate  and dissolved ortho-




               phosphate.  Hydrolyzable phosphorus is  normally




               found  only in sewage-type  samples  and insoluble




               forms  of  phosphorus, as noted,  are determined  by




               calculation.




    1.3  The methods are  usable in  the 0.01  to  1.0 mg P/l range.




         Approximately 15 samples per  hour can  be  analyzed.
                               247

-------
SAMI
\
Total Sample (No Filtration)

' N/
Direct H-SO.
Colorimetry Hydro ly
^f \i/ Colorim
Hydrolyzab
Orthophosphate Orthophos]
Filter (through 0.45y membrane filter)
/
N>
 V Y
Residue Filtrate

Persulfate
sis  Digestion
etry \/ Colorimetry
le 
ihate Phosphorus

N
Direct
Colorimetry
/
Dissolve
Orthophosphate

\
H2S04
Hydrolysis 5
/ Colorimetry .
Diss. Hydrolyzable
 Orthophosphate

Persulfate
Digestion 
, Colorimetry
Dissolved
Phosphorus
Figure 1.   Analytical Scheme for Differentiation of Phosphorus Forms

-------
                                                              (Phosphorus)








2.  Summary of Method




    2.1  Phosphorus is determined by manually  digesting  the  samples




         with ammonium persulfate and sulfuric acid to convert the




         various forms of phosphorus to the orthophosphate  form and




         measurement of this  orthophosphate on the AutoAnalyzer.




    2.2  In this colorimetric method, ammonium molybdate reacts with




         the orthophosphate in an acid medium  to form a  heteropoly acid,




         molybdophosphoric acid.   This acid is reduced by stannous




         chloride to form the intensely colored complex, molybdenum blue,




         which is directly proportional to the amount of phosphorus.








3.  Definitions



    3.1  The various forms of phosphorus are defined in  Table  1.








4.  Sample Handling and Preservation




    4.1  If benthic deposits  are  present in the area being  sampled,




         great care should be taken not to include these deposits.




    4.2  Sample containers may be of plastic material, such  as




         cubitainers, or of Pyrex glass.




    4.3  If the analysis cannot'be performed the same day of




         collection, the sample should be preserved by the  ad-




         dition of 40 mg HgCl~ per liter and refrigeration  at




         4 C.




5.  Interferences




    5.1  Method does not work on  saline waters.
                              249

-------
                                                             (Phosphorus)








6.   Apparatus




    6.1  Acid-washed glassware:  To prevent contamination,  all  glass-




         ware used in the preparation of standards and actual deter-




         minations 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




         detergents should never be used.




    6.2  Technicon AutoAnalyzer consisting of:




         6.2.1  Sampler I




         6.2.2  Continuous Filter




         6.2.3  Manifold




         6.2.4  Proportioning Pump




         6.2.5  Colorimeter equipped with 15 mm tubular flow cell and




                650 my filters.




         6.2.6  Recorder




    6.3  Hot Plate or Autoclave
                                  250

-------
                                                            (Phosphorus)









7.   Reagents




    7.1  Sulfuric acid  solution:   Cautiously  add 310 ml  of concentrated




         sulfuric acid  slowly  and  with  stirring  to  about 600 ml  of dis-




         tilled water.   Cool and dilute to  1  liter.




    7.2  Ammonium molybdate solution:   Dissolve  12.5 g of (NH.)^Mo-O,,. . 4H_0




         in 175 ml of distilled water.   Cautiously  add 77.5 ml of con-




         centrated sulfuric acid slowly and with stirring to 400 ml  of




         distilled water.  Cool.   Add the molybdate solution to  the  acid




         solution and dilute to 1  liter.




    7.3  Stannous chloride solution:  Dissolve 2.5  g of  fresh SnCl_.2H 0




         in 20  ml of hydrochloric  acid. Warming on a hot plate  will aid




         in dissolving  this material.   Dilute to 400 ml.   Stable for 1




         week at room temperature;  one  month  at  4C.




    7.4  Wash water:  Add 40 ml of sulfuric acid solution to 1 liter of




         distilled water and dilute to  2 liters.




    7.5  Stock  Solution:  Dissolve 0.4393 g of pre-dried KH PO   in




         distilled water and dilute to  1 liter.   1  ml =  0.1 mg P.




    7.6  Standard Solution A:  Dilute 100 ml  of  stock solution to 1  liter.




         1 ml = 0.01 mg P.




    7.7  Standard Solution B:  Dilute 100 ml  of  standard solution A to




         1 liter.  1 ml = 0.001 mg P.
                                 251

-------
                                                           (Phosphorus)



    7. 8  Prepare a series of standards by diluting suitable volumes

          of standard solutions A and B to 100.0 ml with distilled

          water.  The following dilutions are suggested:

                                                     Cone.,
                ml of Standard Solution B            mg P/l

                           1.0                        0.01
                           2.0                        0.02
                           5.0                        0.05
                          10.0                        0.10

                ml of Standard Solution A
                           2.0                        0.20
                           5.0                        0.50
                           8.0                        0.80
                          10.0                        1.00

    7. 9  Ammonium persulfate, reagent grade.

    7.10  NaOH-EDTA solution:  Dissolve 65 g NaOH and 6 g EDTA in

          distilled water and dilute to 1 liter.



8.  Procedure

    8. 1  Phosphorus

          8.1.1  Add 1 ml of sulfuric acid solution to a 50-ml sample

                 in a 125-ml Erlenmeyer flask.

          8.1.2  Add 0.4 g 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 50 ml.
                                 252

-------
                                                      (Phosphorus)








      8.1.5   The  sample  is now  ready  for automatic  analysis  as




             outlined  in 8.3 Orthophosphate.




8.2   Hydrolyzable  Phosphorus




      8.2.1   Add  1  ml  of sulfuric  acid  solution  to  a  50-ml sample




             in a 125-ml Erlenmeyer flask.




      8.2.2   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).




      8.2.3   Cool and  dilute the sample to  50 ml.




      8.2.4   The  sample  is now  ready  for automatic  analysis  as




             outlined  in 8.3 Orthophosphate.




8.3   Orthophosphate




      8.3.1   Set  up manifold as shown in Figure  1.




      8.3.2   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.




      8.3.3   Place  wash  water tubes  (see 7.4) in alternate openings




             in Sampler  and set sample  timing at 2.0  minutes.  Use




             distilled water, instead of acid-wash  water when only




             Orthophosphate is  being  determined.
                             253

-------
                                                           (Phosphorus)








          8.3.4  Place standards in Sampler in order of decreasing




                 concentration.  Complete filling of sampler tray with




                 unknown samples.




          8.3.5  Switch sample line from distilled water to Sampler and



                 begin analysis.




          8.3.6  At end of run, clean out manifold system with NaOH-EDTA




                 solution.








 9.   Calculation




     9.1  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,








10.   Precision and Accuracy




    10.1  In a single laboratory,  using surface water samples at




          concentrations of 0.06,  0.11, 0.48, and 0.62 mg P/l, the




          standard deviation  was 0.004 (AQC Laboratory).




    10.2  In a single laboratory,  using surface water samples at




          concentrations of 0.11 and 0.74 mg P/l, recoveries were




          90% and 95%, respectively  (AQC Laboratory).








                               References
 1.  Standard Methods for the Examination of Water and Wastewater, 12th




     Edition, p. 234, Amer.  Pub. Health Asso., Inc., New York, N.Y. (1965),




 2.  M. Gales, Jr., E. Julian, and R. Kroner, "Method for Quantitative




     Determination of Total  Phosphorus in Water."  Jour. AWWA, 58, No. 10,




     1363  (1966).
                                  254

-------
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AMMONIUM SAMPLER 1 _ H
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SAMPLE V^ ^C

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                                     FIGURE 1   PHOSPHORUS  MANIFOLD

-------
                        SOLIDS,  TOTAL








1.  Scope and Application




    1.1  This method is applicable to surface waters,  domestic and




         industrial wastes,  and  saline waters.




    1.2  The practical range of  the determination is from 10 mg/1




         to 30,000 mg/1.








2.  Summary of Method




    2.1  A well mixed aliquot of the test sample is quantitatively




         transferred to a pre-weighed evaporating dish and evaporated




         to dryness at 103-105C.








3.  Definitions




    3.1  Total Solids are defined as the sum of the homogenous sus-




         pended and dissolved materials in a sample.








4.  Sample Handling and Preservation




    4.1  No special precautions  are required.








5.  Interferences




    5.1  Large, floating particles or submerged agglomerates (non-




         homogenous materials) should be excluded from the test sample.




    5.2  Floating oil and grease,  if present, should be included in




         the sample and dispersed by a blender device before aliquoting.
                                257

-------
                                                      (Solids,  Total)








6.   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.)








7.   Procedure




    7.1  Heat the clean evaporating dish to 55050C for 1 hour in




         a muffle furnace.  Cool, dessicate, weigh and store in




         dessicator 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.




         7.2.1  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.




         7.2.2  If the evaporation is performed in a drying oven,




                the temperature should be lowered to approximately




                98C to prevent boiling and splattering of the sample.




    7.3  Dry the evaporated sample for at least 1 hour at 103-105C.




         Cool in a dessicator and weigh.  Repeat the cycle of drying




         at 103-105C, cooling, dessicating 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.
                                258

-------
                                                      (Solids, Total)
8.  Calculation

    8.1  Calculate total solids as follows:

         Total Solids, mg/1 = (Wt. of sample + dish - wt. of dish) 1000
                                           Vol. of Sample
9.  Precision and Accuracy

    9.1  Precision and accuracy data are not available at this time.
                                259

-------
                       SOLIDS,  FILTERABLE








1.   Scope and Application




    1.1  This method is applicable to surface waters,  domestic and




         industrial wastes,  and saline waters.




    1.2  The practical range of the determination is 10 mg/1 to 20,000




         mg/1.








2.   Summary of Method



    2.1  A well-mixed sample is filtered through a standard glass




         fiber filter.  The filtrate is evaporated and dried to con-




         stant weight at 180C.








3.   Definitions




    3.1  Filterable solids are defined as those solids capable of




         passing through a standard glass fiber filter and dried to




         constant weight at 180C.








4.   Sample Handling and Preservation




    4.1  No special precautions are required.








5.   Interferences




    5.1  Highly mineralized waters containing significant concentrations




         of calcium, magnesium, chloride and/or sulfate may be hygro-




         scopic and will require prolonged drying and dessication and




         quick weighing.
                                261

-------
                                                    (Solids,  Filterable)








    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 2.2 cm, without  organic




         binder, Reeve Angel type 984 H, Gelman type A, 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 2.2 cm filter is used).




    6.5  Evaporating dishes, porcelain, 100 mlj volume.  (Vycor or




         platinum dishes may be substituted).




    6.6  Steam bath.




    6.7  Drying oven, 180C2C.




    6.8  Dessicator.




    6.9  Analytical balance, 200 g capacity, 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
                                  262

-------
                                                (Solids,  Filterable)








     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 dessicator and  store until  needed.




7.2  Preparation of evaporating dishes:   Heat  the clean dish to




     550C for one hour in a muffle furnace.  Cool in dessicator




     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 volumetric cylinder.  If sus-




     pended matter is low, a larger volume may be filtered.




7.4  Filter the sample  through the  glass fiber filter and continue




     to apply  vacuum for about 3 minutes after filtration is com-



     plete 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 1802C.




     Cool in a dessicator and weigh.   Repeat the drying cycle




     until a constant weight is obtained or until weight  loss is



     less than 0.5 mg.




7.7  Note:   The filtrate from the test for SOLIDS, NON-FILTERABLE,




     may be used for this determination.
                           263

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                                                    (Solids, Filterable)
8.  Calculation

    8.1  Calculate filterable  solids as follows:

         Filt. solids, mg/1 =  (Wt. of dried residue + dish - wt. of dish) x 1000
                                            Volume of filtrate used
9.  Precision and Accuracy

    9.1  Precision data are not available at this time.

    9.2  Accuracy data on actual sample cannot be obtained.
                                264

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                      SOLIDS,  NON-FILTERABLE








1.   Scope and Application




    1.1  This method is applicable  to surface waters,  domestic and




         industrial wastes,  and saline waters.




    1.2  The practical range of the determination is 20 mg/1 to 20,000




         mg/1.








2.   Summary of Method




    2.1  A well-mixed sample is filtered through a standard glass fiber




         filter, and the residue retained on the filter is dried to




         constant weight at 103-105C.








3.   Definitions




    3.1  Non-filterable solids are defined as those solids which are




         retained by a standard glass fiber filter and dried to con-




         stant weight at 103-105C.








4.   Sample Handling and Preservation




    4.1  Non-homogenous particulates such as leaves, sticks, fish, and




         lumps of fecal matter should be excluded from the sample.




    4.2  Preservation of the sample is not practical.








5.   Interferences




    5.1  Too much residue on the filter will entrap water and may re-




         quire prolonged drying.
                                265

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                                                 (Solids, Non-Filterable)








6.   Apparatus



    6.1  Glass fiber filter discs, 4.7 cm or 2.2 cm, without organic




         binder, Reeve Angel type 984 H, Gelman type A, 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 2.2 cm filter is used).




    6.5  Drying oven, 103-105C.




    6.6  Dessicator.




    6.7  Analytical balance, 200 g capacity, 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.  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 dessicator and store until needed.  Weigh immediately




         before use.




    7.2  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 volumetric cylinder.  If sus-




         pended matter is low, a larger volume may be filtered.
                                266

-------
                                                   (Solids, Non-Filterable)



    7.3  Carefully remove the filter from the membrane filter funnel

         assembly.  Alternatively, remove crucible and filter from

         crucible adapter.   Place in drying oven and dry at 103-105C

         to constant weight.



8.  Calculations

    8.1  Calculate non-filterable solids as follows:

Non-filterable solids, mg/1 = (Wt. of filter + residue - wt. of filter) x 1000
                                            ml of sample filtered



9.  Precision and Accuracy

    9.1  Precision data are not available at this time.

    9.2  Accuracy data on actual samples cannot be obtained.
                                267

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                              SULFATE




                  (Automated Chloranilate Method)








1.   Scope and Application




    1.1  This automated method is applicable to surface waters, dom-




         estic and industrial wastes, and saline waters, in the range




         of 10 to 400 mg SO /I.   Approximately 15 samples per hour can




         be analyzed.








2.   Summary of Method




    2.1  When solid barium chloranilate is added to a solution con-




         taining sulfate, barium sulfate is precipitated, releasing the




         highly colored acid chloranilate ion.  The color intensity in




         the resulting chloranilic acid is proportional to the amount




         of sulfate present.








3.   Sample Handling and Preservation




    3.1  No special requirements.








4.   Interferences




    4.1  Cations, such  as calcium, aluminum, and iron, interfere by




         precipitating the chloranilate.  These ions are removed auto-




         matically by passage through an ion exchange column.
                               269

-------
                                                          (Sulfate)

5.   Apparatus
    5.1  Technicon AutoAnalyzer consisting of:
         5.1.1  Sampler I.
         5.1.2  Continuous filter.
         5.1.3  Manifold
         5.1.4  Proportioning pump.
         5.1.5  Colorimeter equipped with 15 mm tubular flow cell and
                520 my filters'.
         5.1.6  Recorder.
         5.1.7  Heating bath, 45C.
    5.2  Magnetic stirrer.

6.  Reagents
    6.1  Barium chloranilate:  Add 9 g of barium chloranilate  (BaC.-Cl-O.)
         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:  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+.
                                270

-------
                                                          (Sulfate)



         Note:   Column  is  prepared  by  sucking  a solution  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  red.

    6.5  Stock  solution:   Dissolve  1.4790 g of pre-dried  Na-SO. in

         distilled water and dilute to 1  liter.   1  ml  = 1  mg.

         6.5.1   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

                               1.0                      10
                               2.0                      20
                               4.0                      40
                               6.0                      60
                               8.0                      80
                              10.0                     100
                              15.0                     150
                              20.0                     200
                              30.0                     300
                              40.0                     400



7.   Procedure

    7.1  Set up manifold as shown in Figure 1.   (Note  that any  pre-

         cipated BaSC^  and the unused  barium chloranilate  are removed

         by filtration.  If any  BaSC>4  should come through  the filter,

         it is  complexed by the  NaOH-EDTA reagent).

    7.2  Allow  both  chlorimeter  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.
                               271

-------
                                                          (Sulfate)








    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 (AQC), using surface water samples at




         concentrations of 39, 111, 188, and 294 mg SO /I, the standard




         deviations were 0.6, 1.0, 2.2, and 0.8, respectively.




    9.2  In a single laboratory (AQC) using surface water samples at




         concentrations of 82 and 295 mg SO /I, recoveries were 99%




         and 102%, respectively.









                                Reference




1.  R. J. Bertolocini and J. E. Barney, Anal. Chem., 29, 283 (1957).
                                272

-------
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-------
                        TURBIDITY




1.   Scope and Application




    1.1  This method is  applicable  to  surface  and saline  waters  in




         the range of turbidity  from 0 to  40 Jackson units.




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 refer-




         ence suspension.   The higher  the  intensity of scattered




         light, the higher the turbidity.   Readings, in Jackson




         units, are made in a nephelometer designed according to




         specifications  outlined in Apparatus, 5.  A standard




         suspension of Formazin, also  prepared under closely




         defined conditions,  is  used to calibrate the instrument.




         2.1.1  Formazin 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.




3.   Sample Handling and  Preservation




    3.1  Samples taken for turbidity measurements should  be analyzed




         as soon as possible.  Preservation of samples is not recom-




         mended.
                               275

-------
                                                          (Turbidity)








4.  Interferences




    4.1  The presence of floating debris and coarse sediments which




         settle out rapidly will give false high readings.  Finely




         divided air bubbles will also 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 detector with a readout device to indicate the in-




         tensity 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 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




         turbidity differences 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 neces-




         sary to obtain both adequate coverage and sufficient sensitivity




         for low turbidities.
                                276

-------
                                                      (Turbidity)








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:




     5.4.1  Light source:   Tungsten  lamp operated at not less  than




            85% of rated voltage or  more than rated voltage.




     5.4.2  Distance traversed by incident light and scattered




            light within the sample  tube:  Total not to exceed 10  cm.




     5.4.3  Angle of light acceptance of the detector:  Centered




            at 90 to the incident  light path and not to exceed




            30 from 90.




     5.4.4  Maximum turbidity to be  measured:  40 units.




5.5  At the time of this writing, the only instrument commercially




     available with these specifications is the Hach Turbidimeter,




     Model 3100.  This instrument is recommended.
                           277

-------
                                                         (Turbidity)








6.   Reagents




    6.1  Turbidity-free water - Pass distilled water through a 0.45 y




         pore size membrane filter if such filter and water shows a




         lower turbidity than the distilled water.




    6.2  Stock turbidity suspension:




              Solution 1:  Dissolve l.OOg hydrazine sulfate, (HN-^.H SO.,




         in distilled water and dilute to 100 ml in a volumetric flask.




              Solution 2:  Dissolve lO.OOg hexamethylenetetramine 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 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.




7.  Procedure




    7.1  Turbidimeter calibration:  The manufacturer's operating instruc-




         tions should be followed.  Measure standards on the turbidimeter




         covering the range of interest.  If the instrument is already
                                   278

-------
                                                     (Turbidity)








     calibrated in standard turbidity units,  this procedure will




     check the accuracy of the  calibration scales.   At  least one




     standard should be run in  each  instrument  range to be used.




     Some instruments permit adjustment  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-calibrated




     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 tur-




     bidity-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 Turbidimeter, Model 2100,  is equipped with




            5 separate scales:   0-.02, 0-1.0,  0-10.0, 0-100, and
                             279

-------
                                                      (Turbidity)



             0-1000 JTU.  It is strongly recommended, however,

             that the upper scales be used as indications of

             required dilution volumes to reduce readings to

             less than 40 JTU.  (NOTE:  Comparative work per-

             formed in the AQC Laboratory indicates a progressive

             error on sample turbidities in excess of 40 units.)



Calculation

8.1  Multiply sample reading by appropriate dilution to obtain

     final reading.

8.2  Report results as follows:

         Jackson Turbidity                 Record
                Units                   to nearest:
           0.0-1.0                        0.05
             1-10                         0.1
            10-40                         1
            40-100                        5
           100-400                        10
           400-1000                       50
              >1000                       100

Precision and Accuracy

9.1  Precision and accuracy data are not available at this time.
                              280

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