GUIDELINE SERIES
OAQPS NO. 1.2-017
(Revised 5/74)
A DESCRIPTION OF THE ANALYTICAL TECHNIQUES
AND ASSOCIATED SAROAD METHOD CODES USED IN
STORING DATA IN THE NATIONAL AEROMETRIC
DATA BANK
US. ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
[Description of the Analytical Techniques DATE: 3 1 MAY W4
and Associated SAROAD Codes Used in Storing
Data in the National Aerometric Dat^uBank
FROM: OAQPS #1.2-017 j M
n
T
'
Robert E. Neligan, Director ^
T Monitoring and Data Analysis Division
Surveillance and Analysis Division Directors, Regions I-X
Air and Water Analysis Division Directors, Regions I-X
Enclosed is a copy of guideline document OAQPS #1.2-017.
The previous draft has been revised based on comments from
the Regional Offices and NERC-RTP. The document relates
SAROAD pollutant method codes with analytical1 techniques
for which data have been submitted since 1969.
The principal purpose of this guidance is to establish
uniformity in reporting data to 'the NADB as well as to
prevent data from being reported under the wrong code . It
is extremely important that air quality data be reported
under the correct code number because all of our analyses
and air quality trend statistics are derived.. from these :-
code numbers. Incorrectly coded data may" l4ad to incorrect
statements that a site has. exceeded standards.
."* '-"' ''"'. - i
The Regional Office must take the lead and supervise a
survey of the various monitoring techniques and SAROAD method
coding used at each site under their jurisdiction to verify
if they differ from those described in this guideline. We
would appreciate a reply from your office when you have
surveyed the sites under your jurisdiction.
Should a technique or code be usedvthat is not described
in this document, please follow the instructions found on
. page 2 and report any differences to the Chief of the Data .
Processing Section, NADB, Durham, North Carolina (919/688-8247)
If there are any further questions or comments, please
contact Mr. William Cox of the Monitoring and Reports Branch
(919/688-8312) .
Robert E. Neligan
Enclosure
EPA Form 1320.6 (R»». 6-72)
A
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A nnrCP.IPTTON' OF THE .MIALYTICAL TECIII-riQUIiS AND
AHSCCIAT-JD SAROAD METHOD COIDJ:S ucr-iv in
STORING DATA III THE NATIONAL AERCMETRIC DATA BANK
OAQPS 1.2-017
J4arch 1974
Revised
May 30, 1974
Monitoring and Reports Branch
Office of Air Quality Planning and Standards
and
Quality Assurance and Envirc:
Office; o.~. P.oqcarc
I-,Ta t i en a 1 !;:; v ir crjru..-1
r.ontal Monitoring Laboratory
arcii Center
U. S. Envi::o:vnantal 1'rotection Agency
Research Triangle Park, :,'orth Carolina 27711
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TABLE OF CONTENTS
' '.' ' ":- Page
Introduction ' 1
Suspended Particulates 3
Benzene Soluble Organic 3
Soiling Index 4
Light Scatter 4
Radioactivity 4'
Metals, by Hi-Vol, AA, Emission Spectra 6
Arsenic 9
Mercury 9
Water Soluble Particulates 10
Benzo(A)Pyrene 15
Dustfall Procedures 16'
Carbon Monoxide 23
Sulfur Dioxide 24
Hydrogen Sulfide . 27
Sulfation Rate Procedures ' 28
Fluoride Ion 31
Nitrogen Oxides . 32
Ammonium 36
Hydrocarbons 38
Aldehyde . . 39.
Oxidants 40
Ozone 43
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The purpose of this document is to bring together for
the first time a SAROAD code number with a description of
the analytical technique used in gathering data stored in the
National Aerometric Data Bank (NADB). It has long been
needed. The SAROAD code numbers and methods in this
compilation are only those for which data have been sub-
mitted since 1969. The titles of the methods (in capital
letters following the code number) are those v/hich were
assigned in the past and which appear in the computer
printout of Common Parameters and Methods (the "Farm File"),
similar to Code Table 4 of the SAROAD Users Manual.
It is to be emphasized that we do not endorse all of
the procedures described herein. Some are known to yield
.erroneous or misleading data. Nor do we endorse a par-
ticular manufacturer's instrument even though the name is
referred to in a title.. The rule governing the compilation
was: every method used since 1969 together with its Farm
File title is to be included for the purposes of completeness.
Beneath each SAROAD number and title there is a brief
description of the sampling and analysis principles followed
by references which the reader should consult fcjr details.
Whenever possible, we have given references to those pub-
lications which we think should be readily available to
field workers. In no case have we included enough details
for a worker to start an analysis program which will produce
valid data. The references must be consulted.
Instrumental techniques have not been thoroughly re-
ferenced and the instrument user should, consult the pro-
cedure prepared by the manufacturer.
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Through this publication we hope to achieve some degree
of uniformity in reporting data to the NADB. If, for example,
data have been submitted to the Bank under a given code number,
but the description of that method as found in this compilation
is different from the method which was actually used to obtain.
the data/ then the reporter must do one of three things:
a. he must begin submitting data under the proper
code number which agrees with the method actually
used; (data previously reported must be re-reported
under the correct code);
b. the reporter must change his methodology to agree
with the method described and data then submitted
using that code number; or
c. a nev; code number must be applied for.
We encourage the persons who submit data to the NADB
to verify with the laboratory personnel that the SAROAD codes
used agree with the analytical procedures described herein.
If there are problems or questions, we urge you to call the
chief of the data processing section, NADB, Durham, N.C.
(FTS 919/688-8247); or your SAROAD contact or quality control
coordinator in the Regional Office. Also, we will welcome
your pointing out any errors and/or omissions in the text.
There are a few blanks which we have not been able to fill
in.
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11101 91 SUSPENDED PARTICULATE - HI-VOL - GRAVIMETRIC
Air is drawn at 40 to 60 ft-.3/rain through a glass
fiber filter, by means of a blower, and the sus-
pended particles having a diameter between 100
and 0.1 ym are collected. The suspended particulate
is calculated by dividing the net weight. o:f the
particulate by the total air volume'sampled and
reported in density units as yg/m^. Heavy
loading of suspended particulate, oily particulates,
or high humidity can cause reduced air flow
through the filter. Therefore, flow rates should
be measured before and after the sampling period.
1. "Rules and Regulations," Federal Register,
Vol 36, No. 228, U.S. Government Printing Office,
Washington, D.C., (Nov. 25, 1971), p 22388.
2. Intersociety Committee, "Methods of Air
Sampling and Analysis," American Public Health
Association, Washington/ D.C., 1972, p 356.
3. "Air Quality Data for 1967," EPA-APTD-0741, :'
Office of Technical Information and Publications,
Research Triangle Park; North Carolina, 1971,
p 17.
11103 91 BENZENE SOLUBLE ORGANICS - HI-VOL BENZENE EXTRACTION
An 8% aliquot of the filter is placed in a soxhlet
extractor and extracted with 75 ml of benzene for 6 h.
The benzene is evaporated and the residue is weighed and
reported in aerometric units; yg/m^. Errors may result
from non-volatile material in the benzene used for
extraction.
1. Stanley, T. W., J. E. Meeker and M. J. 'Morgan, (1967),
Environ. Sci. and Tech. 1, (11), 927.
2. "Air Quality Data for 1967," EPA APTD-0741, Office
of Technical Information and Publications, Research
Triangle Park, North Carolina, 1971, pp 17-18.
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11201 81 SOILING INDEX CCOH) - TAPE SAMPLER TRANSMITTAMCE
Air is drawn through a 1 in. diameter spot on a con-
tinuous strip of filter paper. The measurement is based
on light transmission through the spot having the col-
lected matter on it,- and reported in COH's (coefficient
of haze) per 1000 linear foot of sampled air. The
standard is a clear spot on the paper. The inlet air
funnel must be kept upside dovm, and sampling lines
must be kept short.
1. Water, Atmospheric Analysis, (1971) , "Annual Book-
of ASTM Standards," American Society for Testing and
Materials, Philadelphia, Pa., Part 23, p 420.
2. "Air Quality Data for 1967," EPA APTD-0741, Office
of Technical Information and Publication, Research
Triangle Park,--North Carolina, 1971, p 20.
11202 91 SOILING INDEX (RUD) - TAPE SAMPLER - REFLECTANCE
The sampling procedure is similar to that of 11201 81.
Measurement of the soiling is based on light reflectance
from the spot and is reported in RUD's (reflectance
unit density) .
1. Water, Atmospheric Analysis, (1971), "Annual Book
of ASTM Standards," American Society for Testing and
Materials, Philadelphia, Pa., Part 23, p 420.
11203 11 LIGHT SCATTER NEPHELOMETER .
Air enters an optically black metal tube at 5 cfm. Light
of 410 nm is scattered from particles in the air stream.
The amount of light scattered at 90° from the main beam
is measured by a phqtomultiplier tube. '
11302 91 RADIOACTIVE-GROSS-BETA-HI-VOL PROPORTIONAL COUNTER
The radioactive matter on a filter paper is counted with
a beta sensitive detector to establish the gross concen-
tration of beta emitters in the sampled ambient air. The
daughter products of natural radon and thoron in the at-
mosphere can be minimized by waiting three days until they
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have decayed. A self-absorption correction must be made
if inert matter on the filter interferes.
1. Intcrsociety Committee, "Methods of Air Sampling and
Analysis/" American Public Health Association, Wash., D.C.,
1972, p 379. ' '
2. Settler, L. R. and G. I. Coats, (1964), "The Determi-
nation of Airborne Radioactivity,"' Amer. Tnd.' Hygiene
Assoc., J. 22, 64.
.3. Schulte, H. F., Monitoring Airborne Radioactivity,
"Air Pollution," Vol II, 2nd Ed., A. C. Stern, Ed.,
Academic Press, New York, N. Y., 1968, p 393.
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12101-12185 ATOMIC ABSORPTION (AA)
Aliquots of samples from the low temperature ashing
procedure are sprayed into a reducing flame by an
atomizer, where metal ions are reduced to the atomic
state. The atoms absorb monochromatic light pro-
duced by a lamp having a cathode made of the element
to be measured. The light absorbed by the atoms in
the flame is a measure of their concentration. The
influence of one element on the excitation potential of
another does not interfere. The analysis of Al, Sb,
i
l\s, Be, Bi, Ba, Cd, Ca, Cr, Co, Cu, Fe, Pb, Mn, Mo,
Ni, Hg, Sn, Ti, V, and Zn is. done by AA. .The AA
is more sensitive than emission spectra for most
metals.
1. W. Slavin, "Atomic Absorption Spectroscopy,n
Interscience Publishers, New York, 1968, pp 69-74.
2. Perkin Elmer Corp., Methods Manual-Analytical
Methods for Atomic. Absorption Spectrophotometry,
The Perkin Elmer Corp., 1968.
3. F. J. Welcher, Standard Methods of Chemical Analysis,
D. Van Nostrand Company, Inc., Princeton, New Jersey,
1966, p 105.
4. Thompson, R. J., G. B. Morgan, and L. J. Purdue,
(1970), "Analysis of Selected Elements in Atmospheric
Particulate Matter by Atomic Absorption," Atomic
Absorption Newsletter 9, (No. 3), 55.
L2102-12185 EMISSION SPECTRA
A solution containing metallic ions is placed between
two electrodes and subjected to 13-15 kilovolts AC
discharge. The spark so created generates enough
heat to atomize the ions and the high voltage excites
many electrons per atom. Spectra characteristic of
each element are fprraed when the electrons return to
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their normal energy levels. Internal standards are
used to reference a knovm spectral line so that other
lines can be located.. NASN uses indium and yttrium
as internal standards: Metals .as Sb, Be, Bi, Ba,
Cd, Cr, Co, Cu, Fe, Pb,'Mn, Mo, Ni, Sn, Ti, Siu, V,
and Zn are analyzed by emission spectra.
1. H. H. Willard, L. L. Merritt, J. A. Dean, "In-
strumental Methods of Analysis," D. Van Nostrand
Company, Inc. 4th Edition, 1965, p 280.
2. P. J. Welcher,"Standard Methods-of Chemical Analysis,"
D. Van Nostrand Company, Inc., Princeton, New Jersey,;'
1966, p 141. ... ' '
3. "Air Quality Data for 1967," EPA-APTD 0741, (1971),
Office of Technical Information and Publication, Research
Triangle Park, N.C.,. 1971, p 19. v ,
12102-12185 " . .LOW TEMPERATURE ASHING PROCEDURE /:<-
i.' '' .' . .-; '"' - ' ' '.
Particulates are^ashed to remove organic matter. A/1'..o'r
^2-an. ,by^,7 in. strip,.of the exposed glass filter (orv\.a .
cprnposit'e1 of, 5-8/MS'trips) is heated' at 150°C for 1 hr;'"at:
1 torr with an 02 flow of 3000 ml/h. ,The .ashed filter.
,is fluxed for 3 h. with 8 ml 'of 20%-^HCl and 32 ml of
40% HNO-,: The acid extract is * concentrated to 1 or-2 ^
' y'3. ' '. ,n ' - '"'
ml-by evaporation, centrifuged, "and the .residue is
v1'. h' ' ' -i\ , ".. '
.washed three times with dilute' HCl. 'Samples from non- :
urban air are then diluted w,i'£Ji dis^til,led H^O to 3 ml/2
in. strip and samples from urban air are diluted to XL4"
j *5 * '.^ ... .- -
ml/9- in. .of filter taken. ,Samples- so prepared are''',
.rfady ;foir emission spectra analysis, but must be diluted
'10 .fold for'AA analysis. ' '.. ;. *'.*'-;&"
1. Thompson, R. J., G. B. Morgan and L. J:. Purdue,
(19'70) "Analysis of Selected Elements in Atmbspheric
\ . -. r
Par,ticulate Matter by Atomic Absorption," Atomic
Absorption newsletter 9, 54.
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12102-12185 MUFFLE FURNACE PROCEDURE
Prior to the invention of the low temperature asher,
organic material was removed by .heating samples to
500°C for 1 h. in a muffle furnace. Samples are then
extracted twice for 1 h. with 40 ial of 1:1 redistilled
HNO., at a temperature just below boiling. The solution
is filtered, evaporated to 4 ml and diluted to 10.4
ml with H20. The samples are then analyzed by the
emission spectrograph. Metals as Sb, As, Be, Bi, Cd,
Cr, Co, Cu, Fe, Pb, Mn, Mo, Ni", Sn, Ti, V, and Zn are
measured by this procedure. This procedure may volatilize
some portion of some.of the metals and thus result in
an unknown fraction recovered.
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12103 93 ARSENIC - HI-VOL NASN-ARSINE-COLORIMETRIC
The arsenates arid oxides of arsenic are extracted from a
2 in. square opposed filter by digestion for 1 hr with .
30 ml of 6 N HC1 at 90°C,.and then reduced to the trivalent
state with KI and SnCl,. Arsine is then generated by Zn
and HC1 Gutzeit procedure. The evolved arsine passes
through a H^S scrubber and into an absorber containing silve
diethyldithiocarbamate. The resulting red complex is
measured spectrophotometrically at 535 nm. Antimony like-
wise forms stibine which also complexes with the-carbamate
but at low concentrations does not interfere with arsenic
determination. High concentrations of Ni/ Cu/ Cr, and
Co interfere with arsine formation. Many interferences
can be minimized by using an internal standard of added
arsenic.
1. Inter society Committee, ".Methods of Air Sampling and
Analysis," American Public Health Association, Wash., D.C.,
1972, p 289.
12142 92 MERCURY - ACID IC1 ATOMIC ABSORPTION
This is a flameless AA technique. The total mercury is
collected through a glass impinger in 30 ml of 0.1N
acidic iodine monochloride at a flow-rate of 200 ml/min.
Hgl^ is reduced to elemental mercury by hydroxylamine
hydrochloride in basic solution which is aerated to
vaporize the mercury. The vapor is passed into a quartz
absorption cell where it absorbs light at 253.7 nm. This
method is not applicable to atmosphere containing less than
50 ng Hg/m of air due to high and erratic-blanks.
1. Hatch, R. W. and W. L. Ott, (1968), "Determination
of Sub-Microgram Quantities of Mercury by Atomic Absorption.
Spectrophotometry," Anal. Chem. 40, p 2085.
2. Lynch, A. L., R. F. Stalzer, and D. T. Lefferts, (1968),
"Methyl and Ethyl Mercury Compounds Recovery from Air
and Analysis," Am." Ind. Hygiene Assoc. JV, 79.
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10
12202 Dl FLUORIDE-III-VOL NILLARD-V.TNTER/SPECIFIC ION ELECTRODE
The Willard-V.'intcr distillation is carried out to remove
interfering ions. Two 1 3/4 in. diameter circles of the
filter are placed in a platinum dish, covered with 10 ml of
» . . *
Ca(OII)2 suspension (2.55 Ca by weight), and evaporated to
dryness over a steam bath. The residue is heated for
30 min. in an oven at 150°C, and ignited in a muffle
furnace at 550°C for 5-6 h. The ash is mixed with
Ig AgC104 and steam distilled using 10 ml of 60% HCiq4
at 135°C. A total of 190 ml of distillate is collected.
The fluoride ion concentration is then measured with a
specific ion electrode. See 42513 91.
1. M. B. Jacobs, (1960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 1U , Interscience
Publishers, Inc., New York, N.Y., p 200.
12203 91 CHLORIDE-HI-VOL-THIOCYANATE
Chloride in the aqueous extract of the hi-vol particulate
sample forms mercuric chloride and liberates SCN ion
from mercuric thiocyanate. The SCN~~ ion forms a colored
+4*+
complex with Fe ion from ferric ammonium sulfate. The
complex is measured colorimetrically at 416 nm.
1. R. B. Fisher, "Quantitative Chemical Analysis,"
W. B. Saunders Co., Philadelphia, Pa. 1957, p 238.
2. Morgan, G. B., E. C. Tabor, C. Golden, and H. Clements,
Automated Laboratory Procedure for the Analysis of Air
Pollutants 66-p 103B, Technicon Industrial Systems,
Tarrytown, N.Y., p 536.
12301 91 AMMONIUM - HI-VOL NESSLER *
Ammonium ion is removed from an 8% aliquot of the filter by-
fluxing the filter in 50 ml of- II20 for 30 min, then placed
in a Nessler tube with 4 ml of Nessler reagent. Should
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11
the solution become cloudy, Rochclle salt solution (lOy oC
KNaC4II406.4H20 in 20.0 ml of .01N NaOH) is added dropv/iao
with shaking. The absorption is read using a No. 54 filter
with a 50 ml glass cell, using a reagent blank as reference.
(Rochelle salt prevents Ca and Mg precipitation at the high
pH of the Nessler reagent).
1. M. B. Jacobs, (I960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 10, Interscience
Publishers, Inc., New York, p 216.
2. G. B. Morgan, E. C. Tabor, C. Golden, and H. Clements
Automated Laboratory Procedures for the Analysis of Air
Pollutants 66-p 108B, Technicon Industrial Systems,
Tarrytown, N. Y., p 536.
12301 92 AMMONIUM-HI-VGL SODIUM PHEMOLATE
Ammonium ions are extracted from a 3/4 in. by 8 in. strip
of the exposed filter by fluxing with 25 ml of H20. The
filtrate is diluted to 50 ml and sodium phenolate and
sodium hypochlorite are added producing a blue complex v:hcn
pH is above 7.0. The absorbance is read spectrophotometrica
at 626 run.
1. Russell, J. A., (1944), "The Colorimetric Estimation
of Small Amounts of Ammonia by the Phenol-Hypochlorite
Reaction," J. Biol. Chem. 156, 457.
2. Morgan, G. B., E. C. Tabor, C. Golden, and H. Clements,
. Automated Laboratory Procedure for the Analysis of Air
Pollutants 66-p 1083, Technicon Industrial Systems,
Tarrytown, N. Y., p 536.
3. "Air Quality Data for 1967," EPA-APTD 0741,
Office of Technical Information and Publication, Research
Triangle Park, N.C., 1971, p 18.
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12
123oc 91 "nrrrj\TE-ni-voL 2,4 XVLENOL
Nitrate nitrates 2,4-xylenol. The nitrated 2,.4-xylcnol
is separated from other water soluble colored substances
by NaOH and toluene. A 3/4 in. strip of the filter is
fluxed in 25 ml of H20, filtered (Whatman No. 1) , and washed
until 50 ml of filtrate is obtained.. A 5 ml sample and
15 ml of 85% H-SO are mixed, cooled, and 1 ml of 1% xylenol
is added. The solution is heated at 60°C for 0.5 h and
diluted to 80 ml. Then, 10 ml of toluene is added and the
mixture is shaken for 2 min. in a separatory funnel. The
lower layer is discarded, 10 ml of 0.4N NaOH added, and
the funnel again shaken for 5 min. The lower aqueous layer
is drawn through cotton into a cuvette. The absorbance
is measured at 435 run.
1. "Selected Methods for the Measurement of Air Pollutants,
U.S. Department of Health, Education, and Welfare "999-AP-
11, Robert A. Ta'ft Sanitary Engineering Center, Cincinnati,
Ohio, May 1965, p 1-1. ' .
2. Pate, J. B., E. C. Tabor, (1962), "Analytical Aspects
of Glass Fiber Filters,."'Am. Ind. Hyg. Assoc. J. 23.
3. Barnes, H., (1950), "A Modified 2,4-Xylenol Method for
Nitrate Estimation," Analyst 75, 388.
12306 92 NITRATE-HI-VOL REDUCTION-DIAZO COUPLING
The nitrate is reduced to nitrite by alkaline hydrazine,
converted to HNO^ which diazotizes sufanilamide,. and couplet
with N (l-naphthyl)-ethylenediamine dihydrochloride which
absorbs light at 535. nm.
1. Morgan, G. B., E. C. Tabor, C. Golden and H. Clements,
Automated Laboratory .Procedure for the Analysis of Air .
Pollutants 66,. ? 10S3, Technicon Industrial System,
Tarrytown, N. Y., p 536.
1(1
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13
2. "Air Quality Data for 1967," EPA-APTD 0741,
Office of Technical Information and Publication,' Research
Triangle Park, N.C., 1971, p 18.
12306 93 NITRATE-III-VOL SPECIFIC ION'ELECTRODE
The aqueous extract of a hi-vol glass 'fiber filter is
analyzed for nitrate ion by means of a specific ion
electrode.
12345 91 PHOSPHATE - HI-VOL-KOLYBDATE STANNOUS CHLORIDE
Phosphate ions in the water extract of the filter are
precipitated as ammonium molybdophosphate in an acid
medium, which is then reduced to a molybdenum blue com-
plex with stannous chloride. The absorbance is read at
650 nra.
1. Water, Atmospheric Analysis, (1971), "Annual Book of'
*
ASTM Standards," American Society for Testing and Materials,.
Philadelphia, Pa., Part 23, pp 41-49.
2. Lundell, G.' E. and J. I. Hoffman, (1923), "Notes on
the Determination of Phosphate,"' Ind. and Eng', Chem. Anal.
Ed. 15, 71.
12403 91 SULFATE - HI-VOL COLORIMETRIC
Water soluble sulfate is reacted with excess reagent con-
taining equivalent amounts of methylthymol blue and BaCl2.
Ba++ and SO? ions form BaS04 leaving a [SO^] equivalent
of free methylthymol blue. If the pH is changed from 2.8
to 12.4 by KOH, Ba4"*" ion forms a chelate with the free dye.
The unchelnted dye is yellow and absorbs light at 460 nm.
1.. Morgan, G. B., E. C» Tabo-r, C. Golden and H. Clements
Automated Laboratory Procedure for the Analysis of Air
Pollutants 66, p 10SB, Technicon .Industrial Systems
Tarrytown, N. Y., p 538.
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14
2. A. L. Lazrus, K. C. Hill and J. P. Lodge, "A New,
Colorimctric Microdetermination of Sulfate Ion in Rainv.-atcr,"
personal communication, Division of Atmospheric Sur-
veillance, Research Triangle Park, N.C., 1965.
3. "Air Quality Data for 1967," EPA-APTD ;0741, .
Office of Technical Information and Publication, Research
Triangle Park, N.C., 1971, p 19.
12403 92 SULFATE-HI-VOL TURBIDIMETRIC
The water soluble sulfate'extract of the filter forms BaSO,
in a BaCl2 solution. Suspended BaS04 particles scatter
light, and the diminished intensity of a light beam is
measured by a turbidimeter.
An aliquot of the filter extract is chosen so that the
sample contains- the equivalent, of 1 to 20 yg/m of SOT.
To the sample diluted to 20 ml, 1 ml of ION HCl is'added,
followed by 4 ml of a glycerol/absolute ethanol solution
(l:2v/v). After mixing, the absorbance is measured at
500 nm and compared with HjO. Then 0.25g of BaCl2 crystals
are added and shaken to dissolve the crystals. After
standing for 40 min. at 20°.C, the absorbance is measured
again.
1. "Selected Methods for the Measurement of Air Pollutants,"
U.S. Department of Health, Education, and Welfare 999 AP-11,
Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio,
May 1965, p 1-1.
2. Water, Atmospheric Analysis, (1971), "Annual Book of .
ASTM Standards," American Society for Testing and Materials,
Philadelphia, Pa., Part 23, pp 50-53.
12602 91 .HYDROGEN. ION CONCENTRATION - HI-VOL pH METER
The. water soluble extract of the filter is tested by a
pH meter and the hydrogen ion is calculated from the pH
value.
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17242 9.1 BF.IIZOCMPYRENE - HI-VOL THIN LAYi:K CHRO.MATOGRAPIIY
This io a technique whereby the benzene soluble organic:;
are separated by means of thin layer chromatography. The
isolated benzo(A)pyrene as indicated by comparison with a
standard is removed from the thin layer plate and.excited
with radiant energy of 470 run. The fluorescence is .neasurod
at 540 ran.
1. Intersociety Committee, "Methods of Air Sampling and
Analysis," American Public Health Association, Wash., D.C.,
1972, p 159.
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16
21101 51 TOTAL DUSTFALL - BUCKET GRAVIMETRIC
A 1 gallon container having a mouth diameter of 4.4 in.
is placed in a copper can (5 in. high and 5 in. diameter) on
stand,(4 ft. above a roof and four stories from the ground).
Five hundred to 1500' ml of antifreeze-treated water is placec
in the container. The collected sample is filtered using
Whatman No. 4HI paper which is then dried and weighed.
The filtrate is evaporated at 105°C, the residue weighed,
and both weights added for total dustfall.
1. M. B. Jacobs, "The Chemical Analysis of Air Pollutants,"
Chemical Analysis, Vol 10, Interscience Publishers, Inc.,
New York, N.Y., (1960), p 37.
21101 71 TOTAL DUSTFALL - BUCKET. - GRAVIMETRIC (APCA)
The dust falls into a glass or stainless steel container,
5 in. in diameter and 10-15 in. high. The top of the con-
tainer is maintained at from 8 to 50 ft. above the ground
and 4 ft. above any surface. Neighboring roof surfaces
must subtend an angle of 30° or less from the horizontal.
Distilled water should be maintained in the container and
a quaternary ammonium salt is added (1 to 2 mg/1) to suppress
algal growth. Isopropyl alcohol may be added as antifreeze.
The 30 day sample is filtered through a 20 mesh screen to
remove extraneous material and treated as method 21101 51
except that samples having antifreeze are evaporated to
dryness at 105°C, 300 ml distilled water is added, and the
sample again evaporated to dryness.
1. "Recommended Standard Method for Containing Dustfall
Survey (APMI-a)," (Nov. 1955), APCA Journal 5, (No. 3),
P 176- .
21101 81 DUSTFALL - BUCKET GRAVIMETRIC (ASTM)
A 6 in. diameter, 12-18 in. high, glass, plastic/ or
stainless steel cylinder, mounted with a bird ring, is
-------
17
ucc to collect the dustfall. The analysis is the same as
method -21101 71. .
1. Water, Atmospheric Analysis, (1971), "Annual Book of -
AGTM Standards," American Society for Testing and Materials,
Philadelphia, Pa., Part 23, p 425.
2. Nader, J. S., (1958), "Dust Retention Efficiencies
of Dustfall Collector," APCA Journal' 8, p 35.
21102 81 ORGANIC FRACTION - BUCKET GRAVIMETRIC (ASTM)
The water insoluble residue and the filter from method
21101 81 are dried, weighed, placed in a soxhlet apparatus,
and extracted for 2 h using 50.ml of benzene. Benzene
should remain in the flask at all times. The remaining
residue and paper are dried at 105*C and weighed to
report the weight loss as organic fraction, BSO (benzene
soluble organics). "
1. Water, Atmospheric Analysis, (1971), "Annual Book of
ASTM Standards," American Society for Testing and Materials,
Philadelphia, Pa., Part 23, p 427.
21113 71 INORGANIC FRACTION - BUCKET GRAVIMETRIC (APCA)'
-------
JLtf
21113 81 IMORCANIC FRACTION - BUCKET GRAVIMETRIC (ASTM)
The combined wo.ight of water insolublcs and soluble
matter corrected for any solid present in a distilled water
blank.
1. Water, Atmospheric Analysis, (1971), "Annual Book of
ASTM Standards,." American Society for Testing and Material/
Philadelphia, Pa., Part 23, p 428.
21114 71 WATER SOLUBLE WEIGHT - BUCKET GRAVIMETRIC (APCA)
The sample is filtered through a 20 mesh screen to remove
extraneous material and if antifreeze was used, the filtrate
is evaporated to dryness over a steam bath or in an oven
at 105°C. Thirty ml of distilled H20 is added, heated to
boil, and the sample filtered through an alundum crucible.
If no antifreeze was used, the sample is adjusted to 300
ml and filtered through the crucible. The filtrate is
evaporated to a small volume. The filtrate is placed in
a weighed platinum crucible (if fluoride is present)' or
else a borosilicate dish and evaporated to 25 ml. It is
evaporated slowly to dryness on a steam bath or in an oven
at 105°C. Dryings are repeated for 3 h periods until
constant weight is obtained.
1. "Recommended Standard Method for Continuing Dustfall
Survey, (APMI-a)," (Nov. 1955), APCA Journal 5 (No. 3), 17.7.
21114 81 WATER SOLUBLE WEIGHT - BUCKET GRAVIMETRIC (ASTM)
The soluble material, described as the v/ater soluble weight
in method 21101 81,is evaporated in a tared platinum dish if
fluoride or caustic materials are' present or else a boro-
silicate dish. The dish is heated slowly until 25 ml
remain. Then a steam bath or a thermoregulated hot plate
is used to evaporate to dryness at a temperature of 99°C.
Drying is continued in an oven at 105°C until a constant
-------
19
weight is obtained. The water soluble we if; lit: is the
difference bctv;een this constant weight am! uare.
1. Water, Atmospheric Analysis, (1971), "Annual Book
of ASTJl Standards," American Society for Testing and
Materials,. Philadelphia, Pa., Part 23, p 427.
21115 51 WATER INSOLUBLE WEIGHT - BUCKET JACOBS METHOD
The collected sample is filtered through a 20 mesh sieve,
and the coarse material discarded. The insoluble material
in the sample is collected on a 9 cm Whatman No. 41 H
filter. Alternatively, a tared gooch crucible equipped with
a light asbestos mat or an alundum crucible could be used.
The weight of the dry solid is reported as water in-
soluble weight.
1. M. B. Jacobs, (1960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 10, Interscience Publishc
Inc., Mew York, N.Y., p 38.
21115 71 WATER INSOLUBLE WEIGHT - BUCKET GRAVIMETRIC (APCA)
The water soluble weight was obtained to report the total
dustfall, method 21101 71. The sample is filtered
through a 20 mesh screen, the volume made to 300 ml, boiled,
and filtered through a weighed 35 ml alundum filter crucible.
The crucible is dried in an oven at 105°C for 3 h, cooled,
and the drying is repeated to constant weight. The increased
weight of the crucible is reported as water insoluble weight.
1. "Recommended Standard Method for Continuing Dustfall
Survey (APMI-a) , (Nov. 1955), APCA Journal 5 (No. 3), 176.
21115 81 WATER INSOLUBLE WEIGHT - BUCKET GRAVIMETRIC (ASTM)
The. material collected on a dried and weighed filter from
method 21101 81, is dried in a weighing bottle overnight
at 105°C. The net weight less the weight of the filter
paper and weighing bottle is the water insoluble weight.
-------
20
1. ,;ntar, Atnosphcric Analysis, (1971) , "Annual Book
oi .\STJ-1 Standards," American Society for Testing and J-Jatcria
Philadelphia, Pa., Part 213, p 427.
2111C 71 TOTAL WEIGHT ASH - BUCKET GRAVIMETRIC CAPCA.) ' .
The water insolubles and the water solubles are ignited
in a dish at red heat for 20 to 30 min, cooled in a
desiccator, reheated and cooled until a constant weight
is obtained. The dish must have been pretreated in the
same manner. The excess weight is the total weight ash.
1. M. B. Jacobs, (1960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 10, Interscience
Publishers Inc., New York, N.Y., p 47.
21116 81 TOTAL WEIGHT ASH - BUCKET GRAVIMETRIC (ASTM)
The total weight ash is the weight of the insoluble and
soluble materials after the removal of BSO and the com-
bustible materials.
-------
223 .1 ; 32, 2212C 92, 22132 92, and 22136 92
COPPER, IKON, MANGANESE, NICKEL - BUCKHT ATOMIC ABSORPTION
Thirty ml of IIN03/II20 (1/1) is added to the due tf all
in a beaker, heated below boiling for 1 h, and concentrated
to remove excess UNOy. The solids are removed by
centrifuging. The solution is 'analyzed by AA. '
1. Water, Atmospheric Analysis, (1971) , "Annual Book of
ASTM Standards/ " American Society for Testing and Materials,
Philadelphia, Pa., Part 23, p 678.
22403 81 SULFATES - BUCKET TURBIDIMETRIC (ASTM)
Turbid samples are filtered and the temperature adjusted
to between 15 and 30°C. Ten ml glycerin solution (glycerin/
II20, 1/1), and 5 ml of NaCl solution (240g of NaCl and 20 ml
cone. HCl/liter) are added to 50 ml of the sample. A 40 mm
cell filled with" the treated sample is used as the blank
sample by setting the colorimeter to zero absorbance at 380-
400 nm. The cell sample is combined with the remaining
treated sample, 0.3g of BaCl2.2H20 crystals added, and the
mixture stirred 'for 1 min. After standing for 4 rain the
mixture is stirred again for 15 sec* The cell is then
filled with the turbid solution and absorbance measured
again at the same wavelength as the blank sample.
1. Water, Atmospheric Analysis, (1971) , "Annual Book of . .
ASTM Standards/1 American Society for Testing and Materials,
Philadelphia, Pa., Part 23, p 51.
22G02 -81 pH (DUSTFALL)i .- 'BUCKET pH METER V
Total acidity of the water soluble portion of the total dust-
fall is obtained by using a pH .meter, or less accurately
by use of pH test paper. . *."" .
1>- M. B. Jacobs^ (1960), "The Chemical Analysis of Air
Pollutants,^! .Chemical/Analysis, Vol 10, Interscience .Publishe:
Inc., New York, N.Y., p 40.
-------
22
25101 81 DUfJTFALL CO:-:',USTIDLE-BUCKET GRAVIMETRIC - 500-DEG.
C. LOSS (ASTM1
After the DSO has been remove, from the water insoluble
material/ the material and the filter paper are ashed at"
500°C in a tared crucible and the weight loss is reported as,
"Combustibles and volatile particulates other than benzene
soluble."
1. Water, Atmospheric Analysis, {1971}, "Annual Book of
ASTM Standards," American Society for Testing and Materials,
Philadelphia, Pa., Part 23, p 428.
-------
42101 12
42101 21
INFRA-RED /
1 The non-diisperive infrared instrument has a sample
cell, a reference, cell, and a detector; The detector
is divided by a flexing diaphragm into two equal
cells filled with equal concentrations of CO. The
reference cell is. filled with a CO free air.
When infrared radiation is passed into the sample
cell some of the radiation is absorbed by CO
in this cell in proportion to the concentration
of CO and the rest is transmitted to the detector.
In the detector, the radiation causes the CO to
expand flexing the diaphragm in proportion to the
transmitted infrared radiation. Since the reference
cell is filled with zero CO air,, the reference cell
side of the detector exerts a constant pressure on the
diaphragm,- When the CO is introduced into the sample
cell, unequal amounts of residual radiation reaches
the two compartment of the detector causing an unequal
expansion of the detector gas. This unequal expansion
causes the diaphragm to deflect, creating a change of
...electrical capacitance in an external circuit, and
ultimately an amplified signal which is suitable for
input to a servo-type recorder. The detector is calibrated
by placing CO standards in the sample cell and recording
the electrical signals.
1. "Rules and Regulations," Federal Register, Vol 36,
No. 228, (Nov. 25, 1971), p 22391.
CARBON MONIXIDE - INSTRUMENTAL - COULOMETRIC
Atmospheric air is drawn through a heated ^Oc column
where Ij is liberated. The ^ is directed
into an electrochemical cell where I2, is measured
coulometrically. *
1. Beckman Instrumention', Bulletin 3000 4411-4,
Beckman Instruments, Inc., Fullerton, California.
CARBON MONOXIDE - INSTRUMENTAL -'FLAME IONIZATION /
Ambient air is. passed through two gas chromatograph-ic
columns in series, the first retains most pollutants
but passes CO nnd Cllq, and the second passes only
CO. The CO then Clows through a Ni catalyst where
-------
it is converted to CH4 which is measured by a flame
ionization dctoccoi. The re.-jult.inn measured current
is related to the CO concentration of the input
ambient air by dynamic calibration with Known CO
concentration standards.
1. Rotterdam, Warsaw, and Bucharest/ "The Status
of Instrumentation in Air Pollution Control," Environ-
mental Control Sorninar Proceeding, U.S. Department
of Commerce, (May 5-June 4, 1971), p 217.
42102 11 CARBON DIOXIDE-INSTRUMENTAL IMFRAR5D ABSORPTION
This procedure is similar to the NDIR procedure for carbon
monoxide, 42101 11, except that water does not have to
be removed from the air stream.
42401 11 SULFUR DIOXIDE-INSTRUMENTAL-WEST CAEKE-COLORIKETIC
A continuous analyzing system is setup such that
the ambient sir flows through a glass beaded absorp-
tion column concurrently with 0.02M sodium tetrachloro-
mercurate. Dichlorosulfitomercurate ion is formed
reacted with acid-bleached pararosaniline and
formaldehyde to produce a red-purple pararosaniline
methylsulfonic acid which is quantitatively measured
colorimetrically. The zero (100%T) baseline is
established with pure reagents for 1 h and the in-
strument is then dynamically calibrated with known
S02 concentration standards. Air flow rate and
reagent flow rate must be calibrated and maintained
accurately.
42401 13 SULFUR DIOXIDE-INSTRUMENTAL-CONDUCTIMETRIC
Sulfur dioxide is absorbed in acidic ^02 whi^-h
oxdizes the S02 to H'2S04. The resulting change
in conductivity can be measured, compensated for
. temperature, and related to the input S02 concentration
by dynamic calibration with known S02 concentration
standards. However, specificity is poor because any
materials that alter the conductivity of the reagent
are potential interfering agents.
1. Bcckman Air Quality Acralyzer Operating and
Service Manual, Scientific and Process Inst. Div. , ,/,(
-------
Fullcrton, California, 1GTW352, (Aug. 1966).
2. Thomas, M.D., (1932)/ "Automatic Apparatus for
the Determination of Small Concentrations of Sulfur
Dioxide in Air," Anal. Chem. 5, 253.
3. M. B. Jacobs, "The Chemical Analysis of Air .
Pollutants/1 Chemical Analysis, Vol 10, Interscience
Publishers, Inc., New York, N.Y.., (I960), p 394.
4. Water, Atmospheric Analysis, (1971), "Annual Book
of ASTM Standards," American Society for Testing and
Materials, Philadelphia, Pa., Part 23, p 272.
42401 14 SULFUR DIOXIDE-INSTRUMENTAL-COULOMETRIC
The air to be measured is passed through a cell
containing a neutral buffered iodide or bromide
electrolyte where an electrical current or potential
maintains a constant concentration of free 12 or Br2.
When S02 in the input air reacts with the I2 o'r Br2,
the change in electrical current or potential necessary
to restore or maintain the original concentration of
12 or Br2 (coulometric titration) is £ quantitative
measure of the S02 input. If the input flow i?ate is
constant, the S02 concentration can be related to
the electrical signal by' dynamic calibration with
\
known SO, concentration standards/
42401 15 SULFUR DIOXIDE-INSTRUMENTAL-THOMAS AUTOMETER
The Thomas Autometer is a conductimetric analyzer
developed in 1929. There are later models. The
method is similar to method 42401 13.
42401 16 . SULFUR DIOXIDE-INSTRUMENTAL-GC FLAME PHOTOMETRIC
Chrorr.atographic columns are used to separate S02,
H2S, CS2, and CH3ca. Effluent from the columns is
burned in a hydrogen-rich flame. A photcmultiplier
tube is used to detect the 395 nm emission band
characteristic of sulfur 1 The electrical signal is
related to the input concentration by dynamic cali-
bration with known SO2, H2S, CS2, or CJUSH concen-
tration standards..
1. H. H. Willard, L. L. Merr'itt, and J. A. Dean,
"Instrumental Methods of Analysis," D. Van Mostrand
Company, 'Inc., 4th Edition, 1965, p 309.
-------
/12.101 Jl f.Ul.riJR DIOXIDH-DAVIS INSTRUMENT-HYDROGEN PEROXIDE
T'r.c novin instrunont is a conductimetric instrument,
and Co uuch, it vs ir.uch like method 42<101 13.
42-101 33 SULFUR DIOXIDE-DAVIS INSTRUiMENT-SEQUENTIAL-CONDUCTIK'-JT.V.:;
Water is deionized by passage through an amberlite
resin column, then its conductivity is measured.
Ambient air, having first passed through n scrubber
of amberlite ro.sin and soda-lime to remove C02/ is
next passed through the deionized water- where the S02
. is absorbed.. The increased conductivity of the water
is a measure of the S02 concentration of the air.
i
' 1. Thomas, M.D. and J. N. Abersold, (1929), "Automatic
Apparatus for the Determination of Small Concentrations
of Sulfur Dioxide in Air," Anal. Chem. 1, 14.
42401 91. SULFUR DIOXIDE-GAS"BUBBLSR-WEST-GAEKE-SULFAMIC ACID
Sulfur dioxide is collected in a ''tetrachlorcmercurate
solution, forming'a stable dichlorosulfitomercurate
complex. When acid bleached pararosaniline is added
to the collected S02 together with formaldehyde,
the amino groups (-NHt) form a red violet compound
called pararosaniline methylsulfonic acid which is
measured spectrophotometrically. The method is des-
cribed in the Federal Register. (The NAS'N procedure,
however, uses 1.725 g/1 sulfamic acid rather than
6 g/1 and does not use EDTA). The sulfamic acid
eliminates interference from oxides of nitrogen.
1. "Rules and Regulations," Federal Register, Vol 36,
No. 228, U.S. Government Printing Office, Washington, D.C
(Nov. 25, 1971), p 22385.
2. tvcst, P. W. and G. C. Gaeke, (1956), "Fixation
of Sulfur Dioxide as Disulfito-Morcurate (II) and
Subsequent Colorimetric Estimation," Anal. Chem. 23,
1819.
3. Intcrsociety Coinmittee, "Methods of Air Sampling
and Analysis," American Public Health Association,
Washington, D.C., 1972, p 447.
4. "Air Quality Data for 1967," EPA-APTD 0741, Office of
-------
Technical Information and Publication, Research .Triangle
Park, N.C., 1971, p 20.
42401 92 SULFUR DIOXIDE-GAS BUBBLER-WEST-GAEKE
This method, is similar to method 42401 91 except
that the sample absorbing reagent is O.lM TCM,
the starch which is used for standardization is
made without mercuric iodide, and sulfamic acid
is not used except when high concentrationsof NO-
are expected. The sulfamic acid is added to the
sample after collection.
1. "Selected Methods for the Measurement of Air Pollutants'
U.S. Department of Health, Education, and Welfare 999 AP-
11, Robert A. Taft Sanitary Engineering Center, Cincinnati,
Ohio, May 1965, p A-l.
2. Nauman, R. V., et al., (1960) , Anal Chem. 32, 1307..
3. West, P.W. and F. Ordoveza, (1962), "final. Chem. 34,
1324.
42401 93 SULFUR DIOXIDE-GAS BUBBLER-CONDUCTIMETRIC
This manual conductimetric method uses the same
principle as the instrumental conductimetric
method. The absorber is a multiple jet bubbler
system and the sampling is not continuous. The
details are described in the reference.
1. Intersociety Committee, "Methods of Air Sampling
and Analysis," American Public Health Association,
Washington, D.C., 1972, p .456.
42402 71 HYDROGEN SULFIDE-TAPE SAMPLER AISI LEAD ACETATE PAPER
Filter paper (Whatman, No. 1} is cut into 2 by 4 in. strips,
impregnated with Pb(C2H.,O2) (10g/10C ml H20 plus 5 ml
CH3COOH) and dried in H2S free air. Air is pumped over the
strips. A concentration of 0.025 mg/1 of H2S gives a
positive test for H2S. The stain on the paper is com-
pared with a color chart for II-S concentration.
1.^ M. B. Jacobs, (19GO), "The Analytical Chemistry of Indus
trial Poisons, Hazards, and Solvents," Chemical Analysis,
Vol 1, Intorsciencc Publishers, Inc., Now York, N.Y.,
P 103.
-------
24 02 9.1 HYDROGEN SULFIDE-GAS BUBBLER METHYLENE BLUE
(100 Mj tube -t- orifice)
Air is bubbled through a Cd(OH)2 solution in a large inn-
pincjor at 1 cfm for 30 min. Ferric chloride solution and
p-aminodimethylaniline test solution are added to the im-
pinger and agitated. The sample is diluted and allowed to
stand for 30 min. The sulfide ion forms a methylene blue
complex. The absorbance of the sample is compared with a
standard which consists of 45 ml of the Cd(OH)2 solution,
amine test solution, and.the ferric chloride.
1. Inter society Committee, "Methods of Air Sampling
and Analysis," American Public Health Association,
Washington, D.C., 1972, p 426.
2. M. D. Jacobs, (1960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 10, Interscience
Publishers, Inc, New York, N.Y. , p 185.
3. Lodge, J. P., et al., (1966), "The Use of Hypodermic
Needles as Critical Orifice," J. Air Poll. Control Assoc.
16_, 197.
4. Scaringelli, F. P., S. A. Frey, B. E. Saltzman, (1967),
"Evalxiation of Teflon Permeation Tubes for use with
Sulfur Dioxide," Am. Ind. Hyg. g^jfoc.' J. 28, 260.
42410 71 SULFATION RATE-LEAD PLATE GRAVIMETRIC (HUEY)
The PbO2 is converted to PbSO4 by the S02 in the ambient
air and the SOT is removed by Na2CO., and .boiling H20.
Barium chloride is used to precipitate the SOT as BaS04 .
The dried BaS04 is weighed and the SO- equivalence is
reported.
-------
29
42'ilO 72 SuLFATION jRATE-L'K/vD PL.Y.E COLORIMETRIC (HUEY)
42410 73 SULFATION RATE-LEAD PLATE TURBIDIMETRIC (HUEY)
Sulfur dioxide reacts with lead peroxide to form lead
sulfate. The amount of SOj formation per unit time is
the sulfation rate. The SOJ is removed from the plate
by boiling Na-CO., solution and the pll is adjusted between'
2.5 and 4.0 so that sulfaspend or sulfaver precipitates
the SO^. The absorbance of the stirred precipitate is
read at 450 nm, turbidimetrically.
1. Intersociety Committee/ "Methods of Air Sampling and
Analysis," American Public Health Association, Wash., D.C./
1972, p 442.
2. Huey, N. A., M. A. Wallar, and C. D. Robson,
(June 1969) "Field Evaluation of an Improved Sulfation
Measurement System." Paper No. 69-133, Air Pollution
Control Association Annual Meeting.
3. Hickey, H. R., and E. R. Hendrickson, (1965), "A
Design Basis for Lead Dioxide Cylinder," J. Air Poll.
Control Assoc. 15, 409.
-------
42'".10 ?:* r.uLFATiou RATE-LEAD pL.v.r: COLORIMETRIC (HUEY)
42410 73 SULFATION RATE-LEAD PLATE TURBIDIMETRIC (HUEY)
Sulfur dioxide reacts with lead peroxide to form lead
sulfate. The amount of SO^ formation per unit time is
the sulfation rate. The SCc is removed from the plate
by boiling Na-CO., solution and the pH is adjusted between
2.5 and 4.0 so that sulfaspend or sulfaver precipitates
the SO^. The absorbance of the stirred precipitate is
read at 450 nm, turbidimetrically.
1. Intersociety Committee, "Methods of Air Sampling and
Analysis," American Public Health Association, Wash., D.C.,
1972, p 442.
2. Huey, N. A., M. A. Wallar, and C. D. Robson,
(June 1969) "Field Evaluation of an Improved Sulfation
Measurement System." Paper No. 69-133, Air Pollution
Control Association Annual Meeting.
3. Hickey, H. R. , and E. R. llendrickson, (1965), "A
Design Basis for Lead Dioxide Cylinder," J. Air Poll.
Control Assoc. 15, 409.
-------
31
1. WilccJdn, D. II. and F. J. J-lcConncl, (1934) , "-The
Measurement of Atmospheric Sulfur Pollution by Means
of Lead Peroxide, J.' Soc. .Chem.... Ind. 53, 385.
2. Kainzcr, A., (1957) , Zemcnt-Kalh-Gyis 10, 281.
3.. "Standard Methods for the Examination of t:7ater and
Waste-water," 12th Ed., American Pvblic Health Assoc.,
Inc., New York, N. Y., 1965, p 147-151.
42410 94 SULFATION RATE-LEAD CANDLE POTASSIUM CARBONATE (NASN)'
This metlK
42410 91.
This method substitutes I^CO^ for Na2C03 in method
42410 95 SULFATION RATE-LEAD CANDLE TURBIDIMETRIC
Gaseous and particulate fluoride in ambient air are
collected by filtration and chenisorption on filter
paper impregnated with sodium -formate. Water soluble
fluorides are extracted from the filter, made basic
with Na^CO^, and coinplexed with citrate ion to reduce
the iron and aluminum interference. The fluoride ion
concentration is measured with a specific ion electrode.
1. Thompson, R. J., T. B. McMullen'and G. B. Morgan,
(1971), "Fluoride Concentrations in the Ambient Air,"
J. Air Poll. Control AGSOC. 21, 484.
42513 91 FLUORIDE HI-VQL SPECIFIC ION ELECTRODE
The concentration of fluoride in an aqueous sample is
measured by means of the fluoride-specific ion electrode.
1. Elfcrs, L. A. and Decker, C. E., (1968), Anal. Chem.,
Vol. 40, p 1G58.
2. Frant, M. S. and J. w. Ross, Jr., (1966) , "Kloctro-Ja for
Sensing-'Fluoride Ion Activity in Solution," Science 154,
1553.
-------
32
42C01 11 NITRIC OXIDE-IHSTRU-i.^T.-.L COLORI.METRIC
NO is; convGrtccl to 1J02 by passing the ambient air through
an aqueous i'v'Mn04 solution. The resulting riO^ is measured
colorimctrically. An independent measurement of tlie ar.bicr.
N02 concentration is required,. This value, subtracter!
from the first, gives a value for the MO concentration. Sc
Methods 42602 11 and 42602 12 for MO2 measurer.en*: nrocc^u.ra
1. Water, Atmospheric Analysis, (1971), "Annual Book
of ASTM Standards," American Society for Testing and
Materials," Philadelphia, Pa., Part 23, p 523.
2. Rogers, L. M., (1958), "Nitric Oxide and Nitrogen
Dioxide in the Los Angeles Atmosphere," J. of Air Poll.
Control Assoc. 8, 124.
3. Saltzman, B. E. , (1954), "Colorimetric Micro-Detsrmina-.:i
of Nitrogen Oxide in the Atmosphere, Anal. Chem., 26, 1949.
4. Thomas, M. D., et.al., (1956), Automatic Apparatus
for Determination of Nitric Oxide and Nitrogen' Dioxide
in the Atmosphere, Anal. Chem. 28, 1810.
42601 14 NITRIC OXIDE-INSTRUMENTAL
When O, reacts with NO to form NO-,
CHEMILUMINESCEHCE
some of the liberated
energy appears in the form of light of 600-875 nm. The
reaction is extremely rapid. The instrument generates
an excess of 0^ such that the quantity of light emitted
from the reaction and measured by the .instrument, is a
direct measure of the NO concentration in the sampled
air. See also 42602 14.
1. Fontijn, A., A. J. Sabadell and J. R. Ronco, (1970),
Anal. Chem. 42, 575.
2. Stevens, R. K., et.al., "Field Performance Characterise.:
of Advanced Monitors for Oxides of Nitrogen, Czonc, Sulfur
Dioxide, Carbon I-Ionoxide, Methane, and Nonmethane Hydro-
carbons," Environmental Protection Agency, Research Triangle
Park, N.C., presented at the APCA Meeting, June 1972.
<7
-------
33
4/!Goi
:;i'i'.iuc o;:iD!>GAS
42602 11
SALTZIIAH (100 in TUDJ: + ORIFICJ ;
lnO and the
Nitrogen o;:ide is oxidized to tI02 by ISln
Method 4 2 CO?. 72 is followed.
1. Intersocicty Committee, "Methods of Air Sampling
and Analysis," American Public Health Association,
Wash. , D.C., 1972, p 329.
NITROGEN DIOXIDE-INSTRUMENTAL COLORIMETRIC
The Lyshkow modification of the Griess-Saltzman reagent
is used in various continuous NO2 analyzers. Users
should consult the manufacturer's literature for details
of reagent preparation.
1. "Rules and Regulations" Federal Register, Vol 38,
No. 110, USGPO Wash., D.C., (June 8, 1973), p 15176.
2. Lyshkov/, ft. A., (1965), "A Rapid Sensitive Colorirr.etric
Reagent for Nitrogen Dioxide in Air" J. Air Poll. Control
Assoc. 15 (No. 10). 481.
42602 12 NITROGEN DIOXIDE- INSTRUMENTAL-COLORIMETRXC
The original Griess-Saltzman reagent is used in
various continuous N02 analyzers. Users should
consult the manufacturer's literature for details
of reagent preparation.
1. "Rules and Regulation," Federal Register, Vol 38,
No. 110, USGPO, Wash., D.C., (June 8, 1973) p 15176.
2. Saltzman, B. E., (1954) "Colorimetric Micro
Determination of Nitrogen Dioxide in the Atmosphere"
Anal. Chem. 26, 1949.
42602 13 NITROGEN DIOXIDE-INSTRUMENTAL-COULOMETRIG
Air' to be measured is passed through a cell containing
neutral buffered iodide-iodine solution causing an
established equilibrium between iodine and iodide
-------
to be unbalanced. The current required to re-
establish the equilibrium (coulometric titratiqn)
is a measure of the input NO? concentration. If
the input flow rate is constant, the NO2 concentration
can be related to the electrical signal by dynamic
calibration with known N02 concentration standards.
42602 14 NITROGEN DIOXIDE-INSTRUMENTAL-CHEMILUMINESCENCE
The ambient air to be measured is drawn over a heated
catalytic converter which reduces N02 to NO. The
NO is then analyzed by method 42601 14, and the
original N02 concentration is obtained by subtracting
the concurrent NO concentration.
1. "Rules and Regulation," Federal Register, Vol 38,
No. 110, USGPO, Wash., D.C., (June 8, 1973) p 15176.
2. NO/NOX/M02 Analyzer Bulletin, Bulletin 4133,
Beckman Instruments, Inc., Fullerton, Calif.
42602 71 NITROGEN DIOXIDE-GAS BUBBLER-JACOBS-HOCKHElSER-
50 Ml TUBE + ORIFICE
Ambient air to be measured is bubbled through a
sodium hydroxide solution where N02 forms a stable
solution of sodium nitrite. The nitrite ion pro-
duced is reacted with phosphoric acid, sulfanilaraide,
and N-l naphthylethylenediamine dihydrochloride,
and measured colorimetrically' at 540 nm
42602 72 NITROGEN DIOXIDE-GAS BUBBLER-SALTAIAN (50 Ml TUBE +
ORIFICE)
The sample'1 is absorbed in the Griess-Saltzman .reagent
and after 15 min the stable pink color is measured
colorimetrically at 550 nm>
1. Intcrsociety Committee, "Methods of Air Sar.ipl.ing
and Analysis," American Public Health Association,
Washington, D.C., 1972', p 329.
2. f.alli'iruin, U. E. , (195-1), "Co.! or i me trie Micro-
Determination oi llitroqon -in the ALmosphorc," ArKO._.
Chcm. 26, 1949. n
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12602 BA NITROGEN'DIOXIDE-GAS 13UBBLER-NASN SODIUM ARSENITE-
ORiriCE
The method is much like method -12602 71 except for
the absorber'1. Ocj/1 of NaAs02). Ambient ;air is in-
troduced into ':.he absorber by means of an orifice
in the bubbler. The orifice is usually not cali-
brated.
1. "Rules and Regulation," Federal Register, Vol 38,
No. 110, USGPO, Wash., D.C., (June 8, 1973), p 15175.
2. Christie, A..A., R. G. Lidzey, and D. W. F. Radford
(1970) , "Field Methods for the Determination of Nitrogen
Dioxide in Air." Analyst 95, 519.
3. Merryman, E. L., et.al., "Effects of NO, C02,
CH4, H20 and Sodium Arsenite.on N02 Analysis,"
presented at the ..Second Conference on Natural Gas
Research and Technology. Atlanta, Georgia, June 5, 1972.
42602 91 NITROGEN DIOXIDE-GAS BUBBLER-JACOBS-HOCHHEISER (100
Ml TUBE + FRIT)
This method is identical to method 42602 71, except
that a fritted bubbler .is used instead of an orifice
bubbler and the volume of the absorbing solution is
doubled.
1. "Selected Methods for the Measurement of Air
Pollutants," U.S. Department of Health, Education,
and Welfare 999-AP-ll, Robert A. Taft Sanitary
Engineering Center, Cincinnati, Ohio, May 1965, p C-4.
2. Purdue, L. J. , et.al.., (1972), "Reinvestigation
of the Jacobs-Hochhoiser Procedure for Determining
Nitrogen Dioxide in Ambient Air," Environ. Sci.
and Tech. 6, 152.
42602 94 NITROGEN DIOXIDE-GAS BU3BLER-NASN-SODIUM ARSENITE-
FRIT
This method is identical to method 42602 '71 except.
that l.Og/1 of NaAs02 is added to the absorbing
solution, and a fritted bubbler is used instead of
an orifice bubbler.
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1. Christie, A. A., R. G. Lidzcy, and D. V7. F. Raclforcl,
(1970), "Field. Methods for the Determination of Nitror/cn
Dioxide in Air." Analyst 95, 519.
2. Merryman, E. L., et.al., "Effects of MO, C02,
CH4, H20 and Sodium.Arsenite on N02 Analysis/"
presented at the Second Conference on Natural Gas
Research and Technology. Atlanta, Georgia, June 5, 1972.
3. "Selected Method for the Measurement of Air
Pollutants," U.S. Department of Health, Education,
and Welfare 999-AP-ll, Robert A. Taft Sanitary
Engineering Center, Cincinnati, Ohio, May 1965,
p C-4.
42G03 11 OXIDES OF NITROGEN-INSTRUMENTAL COLORIMETRIC
The total oxides of nitrogen (NO + N02) are measured
by the methods- 42601 11 and 42G02 12. The instrument
reports the total as NOX (total oxides of nitrogen).
1. Intersociety Committee, "Methods of Air Sampling
and Analysis," American Pxiblic Health Association,
Wash., D.C., 1972, p 325.
42604 91 AMMONIA-GAS BUBBLER- N33SSLER R5AGCNT-50 Ml TUBS + ORIFIC':
Ammonia reacts with the alkaline HgI2.2KI solution
(Nessler reagent) to produce an crange colored complex
that is measured colorimetrically at 400 to 425 run. The
absorbing solution (3.27N H2S04) is returned to the
laboratory after the siir.pling period and Nessler reagent
added' . Rochelle salt is added to pravent Ca and Mg pre-
cipitation.
1. M. B. Jacobs, (1960), "The Chemical Analysis of Air
Pollutants," Chemical Analysis, Vol 10, Interscience
Publishers, Inc., New York, N. Y., p 216.
2. Morgan, G. B., E. C. Tabor, C. Golden, and H. Clements
Automated Laboratory Procedure for the Analysis of Air
Pollutants GG-p 108B, Technicon Industrial System,
Tarrytown, N." Y. , p 538,
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37
3. Water, Atmospherjc Analysis, (1971), "Annual
nook of ASTM Standards," American Society for Testing
ami Materials, Philadelphia, Pa., Part 23, p 236-331.
42GO4 92 AMMOIJIA-GAS BUBBLER-SODIUM PIIEIJOLATE
The chemical principle used is the same as method
12301 92. Ammonia is collected in 0.0504' N H-SO, as
(NH.JpSO. producing a blue complex with sodium
ph.enolate and sodium hypochlorite.
1. Russell, J. A., (1944), "The Colorimetric Estimation
of Small Amounts of Ammonia by the Phenal-Hyppchlorite
Reaction," J. Biol. Chem., 156, 457.
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30
43.101 11 TOTAL ItYDnOC^P^ON'S-^ISTRU^&iTAL FLAMS:
Ambient air is passed into the. instrument where tho
organic compounds present are burnecT in a hydrogen-rich
flame. A sensitive, electrometer coupled with a
recorder measures the current resulting from the
ions produced in the flame. The response is
approximately proportional to the number of carbon
atoms in the sample. The analyzer is calibrated using
methane and the results are reported as methane
equivalents.
1. Intersociety Committee, "Methods of Air Sampling
and Analysis," American Public Health Association,
Wash., D.C., 1972, p 184.
2. "Rules and Regulations," Federal Register,
Vol 36, No. 228, U.S. Government Printing Office,
Wash., D.C., (Nov. 25, 1971), p 22394.
43102 11 NONMETHANE HYDROCARBONS-INSTRUMENTAL FLAME IONIZATIOM
Measured volumes of air are delivered semicontinuously
(4-12 times per hour) to a hydrogen flame ionization
detector to measure its total hydrocarbon (THC) content.
An aliquot of the same air sample is introduced into
a stripper column which removes H20, C02 and hydro-
carbons other than CH.. CH. and CO are passed
to a gas chromatographic column where '
they are separated. The CH^ is eluted first, and
is measured by the flame ionization detector. This
value subtracted from that for THC results in a
measure of the non-methane hydrocarbon (HMHC) concen-
tration of the sampled air. See also 42101 21.
1. "Rules and Regulations," Federal Register, Vol 36,
No. 228, (Nov. 25, 19711, p 22394.
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39
I3>:oi ii. i-yr.'i'iLMir.-i-.'.'-n'KUMEiiTAL- FLA:in. 10:3.1NATION ..
A ntripper chroma t.otjro.nhic column (charcoal) is used to
remove H20, C02 and hydrocarbons, other than CH,.
Ilothane and CO arc then separated by a gas chromato-
graphic column and the CH. measured by a hydrogen
flame ionization detector.
1. Water, /vtmospheric Analysis, (1971) , "Annual .Book
of ASTM Standards," American Society for Testing
and Materials, Philadelphia, Pa., Part 23, p 783.
2. "Rules and Regulations," Federal Register, Vol 36,
No. 228, U.S. Government Printing Office, Wash., D.C., '
(Nov. 25, 1971) , p 22394.
3. Ortman, G. C., (1966) / Anal. Chem. 36;, 644.
43501 11 ALDEHYDE-INSTRUMENTAL COLORIMETRIC
This method is an automated 1-IBTH technique. See 43501 91.
43501 91 ALDEHYDE-GAS BUBBLER MBTH
VJater soluble aliphatic aldehydes (measured as fcrmalydchya
HCIIO) in the ambient air are measured, using an aqueous
3- methyl - 2- benzothiazolone hydrazone hydrochloride
(MBTH) v;hich forms an azihe. The excess MBTH is
oxidized with ferric chloride and reacts with the azine
to form a blue cationic dye in acidic media, measurable
at 628 nm, colorimetrically.
.1. "Selected Methods for the Measurement of Air Pollutants
U.S. Department of Health, Education, and Welfare, 999-AP-l]
Robert A. Taft Sanitary Engineering Center, Cincinnati, Oh:.
May 1965, p F-l.
2. Sawicki, E. , et.al., (1961), Anal. Cljiem. 33, p 93.
3. . Hauser, T. R. and R. L. Cunrr.ins, (1964) ibid..- 36, 679.
4. "Air Quality Data for 1967," EPA-APTD-0741, Office
of Technical Information and Publication,, Research Triang.'.-
Park, N.C., 1971, p 20.
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40
44101 11 TOTAL OXIDANT-i::STRUM2XTAL-ALKALT.NE KI
Identical to method 44101 14 except 1 N sodium-
hydroxide is used instead of the phosphate buffer
in the absorbing solution.
44101 13 TOTAL OXIDANTSr-INSTRUMEMTAL-MAST MODEL 742-2 .
Identical to method 44101-15.
1. Mast, G. M. and H. E. Saunders, (Oct. 1962), "Research
and Development of the Instrumentation of Oxone Sensing,"
Instrument Soc. of Amer. Trans., 1, 375.
2. Bufalini, J. J., (1963), "Gas Phase Titration of
Atmospheric Oxone," Environ Sci Technol 2, 703.
3. Wartburg, A. F., and B. E. Saltzman, (1965),
"Absorption Tube for Removal of Interfering S02 in
Analysis of Atmospheric Oxidant" Anal. Chem. 37, 779.
44101 14 TOTAL OXIDANT-INSTRUMENTAL-COLORIMETRIC-NEUTRAL KI
Air to be measured is contacted with neutral
phosphate buffered potassiun iodide. Oxidants
convert the KI to 12 or KI3 which is measured
spectrophotometrically at 352 run. If the input
air flowrate is constant, the color density can
be related to the oxidant concentration. Analyzers
are calibrated dynamically with known standard
concentrations of ozone. Sulfur dioxide inter-
ference may be minimized by use of a CrO^ pre-
scrubber, which also causes an NO interference.
1. Intersociety Committee, "Methods of Air
Sampling and Analysis," American Public Health
Association) Wash., D.C., 1972, p 356.
2. .Water, Atmospheric Analysis, (1971), "Annual
Book of ASTM Standards," American Society for Testing
and Materials, Philadelphia, Pa., Part 23, p 518.
3. Wartburg, A. F., and B. E. Saltzman, (1965),
"Absorption Tube for Removal of Interfering S02
in Analysis of Atmospheric Oxidant" Anal. Chen. 37,
779.
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40
44101 11 TOTAL OZIDAMT-IilSTRUMEriTAL-ALKALINE KI
Identical to method 44101 14 except 1 M sodium
hydroxide is used instead of the phosphate buffer
in the absorbing solution.
44101 13 TOTAL OXIDANTS-INSTRU:-1SKTAI>MAST MODEL 742-2
Identical to method 44101-15.
1. Mast, G. M. and H. E. Saunders, (Oct. 1962), "Research
and Development of the Instrumentation of Oxone Sensing,"
Instrument. Soc. of Araer. Trans., 1, 375.
2. Bufalini, J. J.> (1968), "Gas Phase Titration of
Atmospheric Oxone," Environ Sci Technol 2, 703.
3. Wartburg, A. P., and B. E. Saltzman, (1965),
"Absorption Tube for Removal of Interfering S02 in
Analysis of Atmospheric Oxidant" Anal. Ch;em. 37, 779.
44101 14 TOTAL OXIDANT-SNSTRUMENTAL-COLORIMETRIC-NEUTRAL KI
Air to be measured is contacted with ne-utral
phosphate buffered potassiun iodide. Oxi.dants
convert the KI to 12 or Kl3 which is measured
spectrophotometrically at 352 nm. If the input
air flowrate is constant, the color density can
be related to the oxidant.concentration. Analyzers
are calibrated dynamically with known standard
concentrations of ozone. Sulfur dioxide inter-
ference may be minimized by use of a CrO-^i pre-
scrubber, which also causes an NO interference.
1. Intersociety Committee, "Methods of Sir
Sampling and Analysis," American Public Health
Association, Wash., D.C., 1972, p 356.
2. Water, Atmospheric Analysis, (1971), "Annual
Book of ASTM Standards," American Society for Testing
and Materials, Philadelphia, Pa., Part 23, p 518.
3. Wartburg, A. F., and B. E. Saltzraan, (1965),
"Absorption Tube for Removal of Interfering S02
in Analysis of Atmospheric Oxidant" Anal,, Chen. 37,
779.
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41
44.101 15 TOTAL OXIDArrr-INSTKUMEXTAL-COULOMETUIC-NEUTK/vL KI
Air to be measured is passed through a cell containing
potassium iodide and two electrodes. Oxidants
convert iodide ions to I2 which is reduced at the
cathode of the cell.'causing a current to flow thru
an external circuit. If the flow rate is constant,
this electrical signal can be related to the input
concentration of oxidants. Analyzers are calibrated
dynamically with known standard concentrations of
ozone.
A
44101 51 TOTAL OXIDANT-GAS BUBBL.ER-PHENOLPHTHALIN
Phenolphthalin, in the presence of CuS04 is
oxidized to phenolphthalein by ambient air oxidants.
Air is passed through 10 ml of reagent at 800
ml/min for 10 min. The color is read using a
colorimeter and a green filter.
1. M. B. Jacobs, (1960), "The Chemical Analysis
of Air Pollutants," Chemical Analysis, Vol 10,
Interscience Publishers, Inc., New York, N. Y.,
p 225.
44101 81 TOTAL OXIDANT-GAS BUBBLER-ALKALINE KI
Oxidants in sampled aiobient air are absorbed in
an alkaline KI solution in a buboler. A stable
product is formed which can be stored with little
loss for several dcys. Analysis is completed
by addition of phosphoric acid-sulfuric acid
reagent, liberating iodine, which is then determined
spectrophotometrically at 352 nm.
1. Selected Methods for the Measurement of Air
Pollutants U.S. DHEW 999-AP-ll, RATSEC Cincinnati,
Ohio, 1965, p E-l.
2. Water, Atmospheric Analysis, (1971), "Annual
Book of ASTi-1 Standards," American Society for Testing
and Materials, Philadelphia, Pa., Part 23, p 391.
3. M. B. Jacobs, (1960) , "The Chemical Analysis of
Air Pollutants," Chemical Analysis, Vol 10, Inter-
scioncc Publishers, Inc., New York, N. Y., p 219.
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44101 C2 TOTAL OXIDANT-GAS BUBBLER-FERROUS OXIDATION
Air to be measured is filtered through a
No. 4 paper at 1 cfia then bubbled through two
impingers in series containing acidified ferrous
ammonium sulfate absorbing solution. Alter sampling
ammoniuru thiocyanate is added, and the resultant
color is measured with a colorimeter and green filter.
1. M. B. Jacobs/ (1960) / "The Chemical Analysis'of
Air Pollutants," Chemical Analysis, Vol 1,0, Inter-
science Publishers, Inc., New York, N. Y., p 228.
44101 83 TOTAL OXIDANT-GAS BUBBLER NEUTRAL BUFFERED KI
This is the reference method for standardization and
calibration of total oxidant and ozone measuring
techniques. Maximum sampling time is 30 minutes.
Sulfur dioxide interferes.
1. Intersociety Committee, "Methods of Air Sampling
and Analysis/1 American Public Health Association/
Wash., D.C., 1972, p 351,
2. "Rules and Regulations" Federal Register, Vol 36,
No, 228, U.S. Government Printing Office, VJash., D.C.,
(Nov. 25, 1971), p 22392.
3. "Selected Methods for the Measurement of Air Pollutant.
U.S. DIIEW, 999-AP-ll, R. A. Taft Sanitary Engineering
Center, Cincinnati, Ohio, May 1965, p D-l.
44103 11 INSTRUMENTAL - TOTAL OXIDANT - 0.2(NO
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43
44201 11 OZONE - i;JSTRfj:-:"r-:TAL-CIIEMILUMINESCI3MCE
Ambient air to be ii.easurcd and ethylene are
delivered siraU3.tr.n-.:ously to a mixing cell where
ozone reacts with the ethylene to emit light which
is measured by a nhotomultiplier tube. If the air
and ethylane flov/ratcs arc constant, .the resulting
photomultiplier signal can be related to the input
ozone concentration. Analyzers are calibrated with
known ozone concentration standards.
1. "Rules and Regulations," Federal Register Vol 36,
No. 228, U.S. Government Printing Office, Washington,
D.C., (Nov. 25, 1971), p 22392.
2. "A ChGiailuminescence Detector for Ozone Measure-
ment," Bureau of Mines Report of Investigation RI-7650,
United States Department of the Interior, U.S. Government
Printing Office, Washington, D.C., 1972.
44201 13 OZONE - INSTRUMENTAL - COULOMETRIC
This method is identical to method 44101 15.
1. Mast, G. M. and H. E. Saunders, (Oct. 1962),
"Research and Development of the Instrumentation of
Ozone Sensing," Instrument Soc. of Amer. Trans.,
1., 375.
:. Bufalini, J. J., (1968), "Gas Phase Titration of
Atmospheric Ozone," Environ. Sci. Tech. 2, 703.
3. Wartburg, A. F., and 3. E. Saltzman, (1965),
"Absorption Tube for Removal of Interfering S02 in
Analysis of Atmospheric Oxidant" Anal. Chem. 37, 779.
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