January  1974
Environmental Protection Technology  Series

          11 *_*,* trtffffttffff;



                   A. H. Ellison

            Chemistry and Physics Laboratory
           National Environmental Research Center
           Research Triangle Park, North Carolina
               Program Element 1AA010
           National Environmental Research Center
            Office of Research and Development
           U.S. Environmental Protection Agency
         Research Triangle Park, North Carolina 27711
                   January 1974

                              RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, Environmental Protection
Agency, have been grouped into five series.  These five broad categories were established
to facilitate further development  and application of environmental technology.  Elimination
of traditional grouping was consciously planned to foster technology transfer and a maxi-
mum interface in related fields.   The five series are:

         1.  Environmental Health Effects Research
         2 .  Environmental Protection technology
         3.  Ecological Research
         4.  Environmental Monitoring
         5.  Socioeconomic Environmental Studies

This report has been assigned to the ENVIRONMENTAL PROTECTION TECHNOLOGY series.
This series describes research performed to develop and demonstrate instrumentation,
equipment, and methodology to repair or prevent environmental degradation from point and
nonpoint sources of pollution. This work provides the new or improved technology required
for the control and treatment of pollution sources to meet environmental quality standards.
Copies of this report are available free of charge to Federal employees, current contractors
and grantees, and nonprofit organizations - as supplies permit - from the Air Pollution
Technical Information Center, Environmental Protection Agency, Research Triangle Park,
North Carolina 27711; or, for a nominal cost, from the National Technical Information Ser-
vice,  Springfield, Virginia 22151.

This report has been reviewed by the Office of Research and Development, Environmental
Protection Agency, and approved for publication.  Approval does not signify that the
contents necessarily reflect the views and policies of the Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement or
recommendation for use.

     This discussion has been limited to EPA's air pollution measurement technique and
instrumentation  research and development program; however, this is not to imply that
research conducted in other government agencies  and in the private sector  have not con-
tributed to the EPA program.  In fact, much of EPA's program  has involved the  evaluation
and application  of technology developed elsewhere.  The bibliography given contains only
the key references.   These references in  turn contain many additional references.


Introduction  	   1

Promulgated and Proposed Standards	   3

Measurement Strategies	   5

Particulate Matter	   6

Sulfur Oxides	   7

Nitrogen Oxides	   8

Photochemical Oxidants	'•	   9

Hydrocarbons	  . , .	10

Carbon Monoxide . • •	11

Hydrogen Sulfide	,	11

Hazardous Air Pollutants:   Mercury,  Beryllium, and Asbestos	*  • •	12

Instrument and Method Calibration  	13

Research Techniques	•	14

References	15

                     OF  AIR  POLLUTANTS

    The Clean Air Amendments of 1970, which became law in December of that year,  di-
rected the Environmental Protection Agency (EPA) to bring  air pollution under control
through the  promulgation of numerous national air pollution standards.   It authorized
the promulgation of ambient air quality standards, standards for new stationary sources
of air  pollution, standards for hazardous air pollutants, standards for mobile source
emissions, and standards for fuels and fuel additives.  In anticipation of the 1970 legis-
lation, EPA's predecessor in the air pollution control program, the National Air Pollution
Control Administration  (NAPCA) ,  which was part of the Department of Health, Education,
and Welfare, started work on a plan for the research and development needed to provide
appropriate measurement techniques and instrumentation for developing and supporting
the various standards to be promulgated. The plan was prepared under contract with
Esso Research and Engineering Company and was completed with EPA funding and pub-
lished  in December of 1971. -'•
    It had been established by NAPCA that the plan should include research for and
development  of measurement techniques for the air pollutants listed below:
1.  Oxides of  sulfur                    10.  Polychorinated biphenyls
    (S02, S03, H2S04)                n   p0iynuciear organic matter
2.  Oxides of  nitrogen                  , _   „   ..   .   ,     ,
    (NOX, NO, N02, HN03)             12'  Reactlve hydrocarbons
->   r>  i.-  i  ±    ±1.   f •   j- ^  -i        13.  Hydrogen  chloride
3.  Particulate matter (size distribution,         '    to
    chemical  composition)               14.  Manganese
4.  Asbestos                          15.  Selenium
5.  Mercury                           16.  Arsenic
6.  Beryllium                          17.  Phosphoric acid
7.  Carbon monoxide                    18.  Chlorine
8.  Nonmethane hydrocarbons            19.  Hydrogen  fluoride
9.  Certain  specific hydrocarbons        20.  Hydrogen  sulfide


21.  Mercaptans                            29.  Boron
22.  Ammonia  and amines                   30.  Tin
23.  Organic  acids                          31.  Lithium
24.  Aldehydes                             32.  Chromium
25.  Odor                                  33.  Vanadium
26.  Photochemical oxidants                 34.  Cadmium
27.  Copper                                35.  Lead
28.  Zinc                                   36.  Aeroallergens
      Two determinations were then made  for each of those pollutants:  the- type of air
 pollution standard that probably would  be needed and the type of measurement method-
 ology that would be required to develop and support an appropriate standard.  Of
 course, the need for appropriate sampling procedures and supporting  measurements such
 as those required to calculate mass rates  from- measured concentrations of a pollutant  in
 a source emission had  to be addressed  in the plan.
     For the most part, the air pollution measurement technique and instrumentation
research and development  program of EPA is being carried out according to plan.
Because of funding limitations, however, the various tasks will be completed later than
indicated in the original plan. -Also, research and development requirements not en-
visioned at the time the plan was prepared are being added to the program as needed.


       As of the summer of  1973, National Ambient Air Quality Standards had  been promul-
  gated for  SOo, particulate matter,  photochemical oxidants,  hydrocarbons, nitrogen dioxide,
  and carbon monoxide. ^  Standards of performance for new stationary sources had been
  promulgated for particulate matter,  sulfur  dioxide, and nitrogen oxides from fossil-fuel-
  fired steam generators; particulate matter from  large incinerators; particulate matter from
  Portland cement plants; nitrogen oxides from  nitric  acid plants;  and sulfur dioxide and
  acid  mist  from sulfuric acid plants.3  New-source performance standards had been pro-
  posed for  particulate matter from asphalt concrete plants;  particulate matter, carbon
  monoxide, sulfur dioxide,  and hydrogen sulfide from petroleum refineries;  hydrocarbons
  from  storage  vessels  for petroleum liquids;  particulate matter  from  secondary lead smelt-
  ers;  particulate matter  from secondary brass  and bronze  ingot production plants;  and  par-
  ticulate matter from  sewage treatment  plants. 4
       By this  same time, hazardous air pollutant standards  had been promulgated for
  asbestos from asbestos mines, .asbestos mills, manufacturing operations, the repair or
  demolition of  buildings  or  structures,  spraying  operations, and roadway surfacing opera-
  tions;  for  beryllium from  machine shops, ceramic plants, propellant plants,  foundries,
  extraction  plants, and incinerators for disposal  of toxic substances;  and mercury from
  ore processing plants and chloralkali plants. 5
       Also  by  the summer  of 1973,  emission standards  for carbon  monoxide, hydrocarbons,
  and nitrogen  oxides from  light-, medium-,  and  heavy-duty vehicles had been promulgated.
  A standard for smoke from new heavy-duty diesel engines  had been promulgated."  Regu-
  lations  had also been promulgated,  and others  proposed," for lead  and phosphorus
  additives in gasoline  but measurement techniques for these additives had not yet been
  specified.   Emission standards had been promulgated for  certain  types of aircraft engines"
  and proposed  for other types.  ^
       Although not proposed or promulgated to date, appropriate standards are being
  considered for other pollutants among the 36 listed above.  Detailed measurement proce-
  dures are  usually included as  part of the standards, but some standards rely on the
  estimated effectiveness of  required  control  measures-e .g.,  floating roofs for  storage
  vessels for petroleum liquids-rather than on  monitoring of emissions by means of
  specified techniques.
     Air pollution control legislation prior to 1970 provided for  the achievement of ade-
quate air quality by  state and local  agencies on the basis of Federal  criteria. H~l°  It
also  contained  authority for  establishing emission standards for  light-duty vehicles.  Thus
the research program for development of measurement techniques and instrumentation
in support of pre-1970 legislation was concerned  mostly with air quality  and light-duty

vehicle emissions.  This program has borne fruit and it will be apparent in the discussion
below that great progress has already been made in these areas. !7,18 The 1970 legislation
called for the control of emissions from stationary sources as rapidly as possible and author-
ized EPA to set standards based on the best control technology available.  A major effort had
to be mounted to provide stationary source emission measurement techniques in support of
the additional control activities called for by the 1970 legislation. ^

                           MEASUREMENT STRATEGIES

     At present, various measurement strategies  are  being considered for  use in the  air
pollution control program.   For example,  air pollutant levels in an urban  area or  a
small locality may  be measured by means  of  one  or several monitoring stations or, if
current research is successful, it may be possible to measure pollutant levels through
the use of long-path spectroscopic  techniques.  Stack emissions from stationary  sources
may be measured by extraction of a sample of the effluent gas  followed by conventional
analysis,  or by the use of an across-the-stack optical technique, or by remote measure-
ment of the stack plume.  Not  only do control activities  require pollutant measurements,
but studies on the effects of air pollutants on human  subjects in an  urban area require
them as well.  Data on health-related  pollution may be obtained through multistation
monitoring of pollutant levels in the locality where the subjects  live and work or by
providing the individuals with  miniaturized portable instruments that can record and
integrate their exposure  to pollution.  There  are  needs for the  continuous measurement
of air pollutant  levels in the air or in a source emission that would require appropriate
instrumentation,  and there are  needs that  require the periodic  collection of samples
(in a bubbler, on  a solid absorbent, on a filter,  in an evacuated cyclinder, or  in an
expandable  plastic  bag) , followed  by analysis in  a central laboratory.

                                  PARTICULATE  MATTER
     Particulate  matter  in  ambient air  is measured by means of the high-volume  sampler.
Results of relatively high  precision are obtainable by this method,  as a  collaborative
test has shown. 20  Jt is generally agreed,  however, that improved measurement method-
ology is needed  for  ambient air participate matter.   Methods that provide particle size
fractionation, at  least into two  size fractions, are the objects of  much of the research.
     Particulate  matter  in  emissions  from stationary sources  is measured gravimetrically
after collection with the EPA  sampling train.    It is  known that  under certain conditions
particulate matter  can form in this sampling system .  Particulate matter  can also remain
within the sampling  probe; thus a procedure for removing and weighing this portion of
the collected sample is needed.  There is much interest in the development of method-
ology for the continuous measurement of particulate matter in ambient air and source
emissions; one program is  aimed at developing suitable instrumentation based on the
attenuation of beta radiation by particulate  matter collected  on a filter.21
     The  chemical characterization of particulate matter is important not only as  a means
of identifying sources of atmospheric particulate matter but also  for identifying specific
chemical elements  or compounds for  which  standards might be promulgated.  Of  the
several techniques for chemical analysis of particulate matter that are possible,  x-ray
fluorescence appears especially promising.22   This technique may supplement or replace
previously used  techniques such  as  atomic  absorption  spectrophotometry, emission spec-
troscopy, and neutron activation analysis.
     Numerous problems have been encountered in  the  use of  filters for collecting parti-
culate matter.  No one  filter  material is  suited  to all tasks.  Chemical analysis of parti-
culate matter by X-ray fluorescence requires very low background levels of impurities..
Mass measurement by beta attenuation requires low mass per unit area for  maximum
sensitivity; however, the  strength necessary for use and handling  must be maintained.
Adsorption or absorption by filters of materials in the  gas phase (i.e., water and
organics) has been a major unresolved problem. Several active programs  are addressed
at solving these  problems.

                                     SULFUR  OXIDES
     Sulfur dioxide in ambient air is  measured by the pararosaniline method. ^  A  col-
laborative test of this method has shown that satisfactory precision is obtained. ^3 Sulfur
dioxide (803)  in  ambient air  can be measured  continuously by means of  a  flame  photo-
metric detection  system.   The detector measures  total sulfur and therefore  can be used
only when it is known that SC>2  is the major (<95%) sulfur-containing  species present24
or after  sulfur compounds  are separated by gas-liquid chromatography."  SC>2  in  fossil-
fuel-fired power plants is  measured by collection of SO£ in 3% hydrogen  peroxide and
subsequent titration using  barium perchlorate with a thorin indicator. 3  A  sampling train
is used in which SCH and  t^SO^ are removed by collection in 80% isopropanol.  For the
measurement of SO2>  SC>3, and H2SO4  mist from  sulfuric acid plants,  a filter is added
between  the 80%  isopropanol  collection  solution  and the 3% hydrogen peroxide collection
solutions.  Sample probe washings, 80% isopropanol collection, and filter washings are
considered to be  sulfuric acid mist; the fraction  collected in 3% hydrogen peroxide is
SO2-   Both fractions are analyzed for  sulfur oxide content by the barium perchlorate
titration  using  thorin  as  an indicator. 3 Sulfur dioxide in power plant stack  emissions
may  be measured continuously by nondispersive  infrared spectroscopy  (NDIR) with
suitable sample conditioning to remove particulate matter and water vapor and to reduce
gas temperature  to near  ambient. 26

                                  NITROGEN OXIDES
     Nitrogen dioxide (NC^) in ambient air has been measured by a 24-hour method that
involves collection in a sodium hydroxide solution to form a stable solution of sodium
nitrite that is then determined colorimetrically by a diazotization reaction; however, this
method has been found to be inadequate because of variable collection efficiency and the
interference  of NO.    Intensive work is being done to develop  and evaluate  improved
collection techniques.    These efforts involve the evaluation of several  collection  solutions
such as those described by Christie,29 Saltzman.^O and Mulik et al.'l  To be adequate,  a
method must have a high degree of specificity and a constant collection efficiency.  Con-
tinuous measurement of NC>2 in ambient air is accomplished by a procedure based on the
chemiluminescent reaction between NO and ozone.    -NO2 is converted to NO in a suitable
sampling system.  The sample is alternately passed directly to the chemiluminescence
detection chamber and indirectly to the detection chamber via the converter so that the
technique measures first NO and then NO plus NO2> permitting, by difference, a
determination of NO2 • The nitrogen oxides stationary source and mobile source  emission
standards are for NOX, that is, NO2 plus NO.  Mobile source emissions of NOX are
measured by the  chemiluminescence procedure described for ambient air. -^ The sampling
system uses  a thermal reactor for the  conversion of NO to N©2 • Nitrogen oxides  in power
plant emissions are collected in a dilute sulfuric acid-hydrogen peroxide solu-
tion and measured colorimetrically using phenol disulfonic acid.^ An electrochemical
technique and nondispersive ultraviolet and NDIR spectroscopy have been proposed
as methods for the continuous  measurement of NOX in power plant emissions. ^3

                          PHOTOCHEMICAL OXIDANTS

     It has been shown that after  correction for NO2 ozone comprises virtually all of
photochemical oxidant.  Consequently, the ambient air standard for photochemical oxidants
is based on a measurement technique for ozone.  The measurement technique uses the
chemiluminescent reaction that occurs between ozone and ethylene. This technique per-
mits the continuous measurement of ozone,2 as well  as the 1-hour measurement on which
the air quality standard for ozone is based.  A collaborative test of this chemiluminescence
method showed that satisfactory precision can be obtained. ^ Since oxidant is formed in
the atmosphere by photochemical reactions involving  hydrocarbons  and nitrogen oxides,
there is no need for source measurements of ozone.  Rather, photochemical oxidants are
controlled by limiting the emission of hydrocarbons.

     Hydrocarbons in the ambient air are measured  by a flame ionization detector.
Since methane does not participate in photochemical  reactions that form oxidants, values
for methane  are  subtracted from  the  total hydrocarbon measurement.   This  is  done  by
means of a  stripper column and  an analytical column that remove interfering substances
and allow only methane to pass through.  Thus,  the sample is alternately passed directly
to the detector and indirectly to  the  detector through the stripper and analytical columns,
which retain  all  hydrocarbons  except methane.
     Hydrocarbons in mobile source  emissions are measured by a flame  ionization  detector
or by NDIR.   Flame  ionization detection is  used for aircraft and all vehicles; however,
NDIR can be  used for heavy-duty vehicles.   The measurement is for total hydrocarbons.
Methane has been a minor constituent of mobile source  hydrocarbon emissions, so that
no  correction for methane is presently made.  However, the catalytic  devices  that •will  be
used in  future vehicles tend to result in less effective oxidation  of methane.   Methane may
then constitute a larger fraction  of the hydrocarbons emitted from vehicles.   Further, it
is now believed  that other hydrocarbons such as ethane,  propane,  acetylene,  and  benzene
may be relatively unreactive in the formation of photochemical  oxidant.  Thus, work  to
develop measurement techniques for these hydrocarbons is under way should it be deemed
advisable to subtract  them along  with methane from  total hydrocarbon measurements.
No  stationary source emission  standards  for hydrocarbons  have been promulgated or  pro-
posed by EPA that require hydrocarbon measurement.

                                CARBON  MONOXIDE
     Carbon monoxide in ambient air^  and in mobile" and stationary^ source emissions is
measured  by nondispersive infrared spectroscopy.  A  collaborative test of the  method
for ambient  air analysis showed satisfactory precision  of the method. 35

                               HYDROGEN  SULFIDE
     Hydrogen  sulfide emissions from petroleum refineries  are measured by collection in
alkaline cadmium  hydroxide  solution to form  cadmium sulfide.  The precipitated cadmium
sulfide is  then  dissolved in  a  known volume  of HC1- acidified  iodine solution.   The iodine
consumed  is a measure of the  H2S present. ^

                          HAZARDOUS  AIR  POLLUTANTS:
                    MERCURY, BERYLLIUM,  AND  ASBESTOS

     Mercury,  beryllium,  and asbestos have been designated hazardous air pollutants and,
as stated  above,  emission  standards for them have been promulgated.
     Stationary source mercury emissions,  both particulate and gaseous, are  measured
after appropriate sampling by  collection in  an iodine monochloride solution.   The mercury
collected is reduced to  elemental mercury in basic solution by dihydroxylamine sulfate.
Mercury is purged from the solution using  a zero-grade air stream and analyzed using '
an atomic absorption spectrophotometer in  the flameless mode.-*
     Beryllium is measured after appropriate sampling  by digestion in an acid  solution
and subsequent analysis by means of atomic absorption spectrophotometry.
     An appropriate method for measuring  asbestos  emissions is not available.  An electron
microscope  technique is  used to  determine  asbestos  in filtered ambient air samples36 but
this  technique is not rapid enough to  support an  emission standard.  Current work is
under way to provide an adequate technique for measuring source emissions of asbestos.

       Calibration of air pollution measurement techniques is exceedingly important and
 in many cases requires close attention to experimental details. Various types of air
 pollutant reference  samples are in use.  Permeation tubes for SO2 are available as
 standard reference materials from the National Bureau of Standards;   a similar device
 for NC>2 is being perfected. ^° Calibrated ozone generators are being used.  ° Small
 gas cylinders containing known amounts of carbon monoxide"*^ or hydrocarbons^! are
 being evaluated as  reference standards.  A large batch of atmospheric particulate matter
 is being collected so that it  can be completely characterized physically and chemically
:and then used as a  reference for particulate matter measurement techniques.  ^  A gas-
1 phase titration of NO and ozone to produce NC>2 has been developed so that the calibra-
 tion of techniques for NO, NO2, and ozone can be accomplished with a reference sample
 of any one of the three constituents-^0

                               RESEARCH  TECHNIQUES

     In addition to  the measurement techniques that have been developed for the purpose
of determining  compliance  with an air pollution standard,  measurement techniques  are
needed for  the  research  program that must be conducted to develop  the  information needed
in the setting of a  standard.   Virtually the entire  spectrum of analytical techniques is used,
including spectroscopy-particularly infrared spectroscopy^^-gas chromatography ,44
electron microscopy, x-ray fluorescence, x-ray diffraction, mass spectroscopy,  emission
spectroscopy, and neutron  activation analysis.  For the most part,  these methods employ
laboratory instruments, so  that techniques must be used that will permit samples to be
collected  in  the field  but brought to the laboratory for  analysis.  In some instances,
however, it is  possible to  install equipment of  this type in mobile laboratories so that
measurements can be made in  the  field.
     Remote and long-path optical techniques for measurement of pollutants in ambient air
or in stationary source effluents are being developed. 45   in some instances, the instruments
utilized in these techniques use broad-band artificial light sources;  in other cases, the
sun's radiation  is used;  and,  in others,  laser  sources  are used.  Research and develop-
ment  costs for  this  type  of instrumentation are high, and  significant technical  problems
exist  in certain applications.   However, the potential effectiveness of air pollution
measurement and monitoring by means of  these techniques justifies a reasonable effort
to investigate their  usefulness.
     The resolution of the problem of preventing environmental  degradation in nonurban
areas46 will require more  sensitive measurement techniques than presently are available.
Also, it will be necessary to  use these techniques  to establish a base  of data against
which degradation  can be  assessed.


 1.  A Working Document for Air Pollution Measurement Techniques  Development Fiscal
     Years 1972-1977. Prepared for EPA under Contract number CPA 22-69-154 by ESSO
     Research and Engineering Company. Publication number EPA-R4-73-015.
     Research Triangle Park, N.C. December 1971.

 2.  Federal Register.  36(84): 8186-8201, April 30,  1971.

 3.  Federal Register.  3_6(247): 24876-24895, December 23, 1971.

 4.  Federal Register.  3JK111): 15406-15415, June 11, 1973.

 5.  Federal Register.  38_(66): 8820-8846, April 6, 1973.

 6.  Federal Register.  37(221): 24250-24320, November 15, 1972.  .

 7.  Federal Register.  38_(6): 1254, January 10, 1973.

 8.  Federal Register.  38(6): 1258, January 10, 1973.

 9.  Federal Register.  38_(136): 19087,  July 17, 1973.

10.  Federal Register.  38(136): 19050,  July 17, 1973. .

11.  Air Quality Criteria for Sulfur Oxides.  DHEW, PHS, National Air  Pollution Control
     Administration.  Publication number AP-50.  Washington, D .C.  April 1970.

12.  Air Quality Criteria for Particulate Matter.   DHEW, PHS,  National Air Pollution  Control
     Administration.  Publication number AP-49.  Washington, D.C.  January 1969.

13.  Air Quality Criteria for Carbon Monoxide.  DHEW, PHS, National Air Pollution Con-
     trol Administration. Publication number AP-63.  Washington, D.C. March 1970.

14.  Air Quality Criteria for Photochemical Oxidants.   DHEW, PHS,  National Air Pollution
     Control Administration.  Publication number AP-63.  Washington,  D .C.  March 1970.

15.  Air Quality Criteria for Hydrocarbons.   DHEW, PHS, National Air  Pollution Control
     Administration.  Publication number AP-64.  Washington, D.C.  March 1970.

16.  Air Quality Criteria for Nitrogen Oxides.  U. S. Environmental Protection  Agency,
     Air Pollution Control Office.  Publication number AP-84.  Durham, N.C. January 1971.

17.  Stevens, R.K.  and A.  E. O'Keeffee.  Modern Aspects of Air Pollution Monitoring.
     Anal. Chem. 42^(2): 143A-149A, February 1970.

18.  Stevens, R.  K.  and J. A. Hodgeson.  Applications of Chemiluminescent Reactions
     to the Measurement of Air Pollutants. Anal. Chem. 4^(4): 443A-449A, April 1973.

19-  Nader, J.S.  Developments in Sampling and Analysis Instrumentation for Stationary
     Sources.  JAPCA.  2_3(7):  587-591,  1973.

20.  McKee,  H.C., R.E. Childers, and O. Saenz, Jr.  Collaborative Study of Reference
     Method for the Determination of Suspended Participates in the Atmosphere (High
     Volume Method) . Prepared for EPA by Southwest Research Institute under Contract
     number CPA  70-40. NTIS Publication number PB 205-892. Springfield, Va.  June 1971.

21.  Development of a Nucleonic Particulate Emission Gauge.  Final Report.  Prepared for
    EPA by Industrial Nucleonics under Contract number 68-02-0210.  NTIS Publication
    number PB 209-954.  Springfield, Va.  1972.

22. Development of X-Ray Fluorescence Spectroscopy for Elemental Analysis of Particulate
    Matter in the Atmosphere and in Source Emissions.  Prepared by the Naval Research
    Laboratory under an Interagency Agreement with EPA. Publication number EPA-R2-72-063.
    Research Triangle Park,  N. C.  October 1972.

23. Collaborative Study of Reference Method for Determination of Sulfur Dioxide in the Atmos-
    phere (Pararosaniline Method) . Prepared for EPA by Southwest Research Institute under
    Contract number CPA 70-40.  NTIS Publication number PB 205-893.  Springfield, Va.
    September 1971.

24. O'Keeffe, A.E. and G.C. Ortman.  Absolute Calibration of a Flame Photometric Detector
    to Volatile Sulfur Compounds at Sub-Part-Per-Million Levels. Envir. Sci. and Tech.
    3(7): 652-655. July 1969.

25. Stevens, R.  K.,  J. D. Mulik, A. E. O'Keefe,  and K J.  Krost.  Gas Chromatography
    of Reactive Sulfur Gases in Air at the Parts-Per-Billion Level.  Anal. Chem. 4_3: 827-831,
    June 1971.

26. Monitoring Instrumentation for the Measurement of Sulfur Dioxide in Stationary Source
    Emissions.  Prepared for EPA by TRW Inc. , under Contract number EHSD 71-23. NTIS
    Publication number PB220-202.  Springfield, Va .  1973.

27. Hauser, T. R. and C. M. Shy.  Position Paper:  Nox Measurement. Env. Sci. Tech.
    6:890-894, 1972.

29. Christie, A. A., R. G. Lidzey, andD. W. F. Radford.  Analyst.  95:519, 1970.

30. Saltzman, B. E.  Colorimetric Microdetermination of Nitrogen Dioxide in the Atmosphere.
    Anal. Chem.  26:1949,  1954.

31.  Mulik, J. , R. Fuerst, M. Guyer, J. Meeker, and E. Sawicki.  New Methods for the
    Collection and Analysis of Atmospheric NC>2.  Paper presented  at 165th National ACS
    Meeting, Dallas,  Texas, April 8-13, 1973.

32. Sigsby, J. E., F. M. Black, T. A. Bellar, and D. C. Klosterman. Chemiluminescent
    Method for Analysis of Nitrogen Compounds in Mobile Source Emissions  (NO,  NO?, and
    NH3). Envir. Sci. Tech.  7:51-54, 1973.

33. Snyder, A.  D. et al. Instrumentation for the Determination of Nitrogen Oxides Content
    of Stationary Source Emissions. Prepared for EPA by Monsanto Research Corp.  under
    Contract number EHSD 71-30.  NTIS Publication numbers PB 204-877 and 209-190.  Spring-
    field, Va.

34. Collaborative Study of Reference Method for the Measurement of Photochemical Oxidants
    Corrected for Interferences Due to Nitrogen Oxides  and Sulfur  Dioxide.  Prepared for
    EPA by Southwest Research Institute under Contract number CPA 70-40.  July 1973.

35.  Collaborative Study of Reference Method for the Continuous Measurement of Carbon Mon-
    oxide in the Atmosphere  (Non-Dispersive Infrared Spectrometry) . Prepared  for EPA by
    Southwest Research Institute under Contract number CPA 70-4  .  NTIS Publication number
    PB 211-265. Springfield, Va. May 1972.

36. Development of a Method for the Determination of Asbestos in Ambient Air.  Prepared for
    EPA by Battelle Memorial Institute under Contract number CPA 22-69-110.  August 1971.

37. National Bureau of Standards.  Washington, D .C.  Technical Note 585 .  January 1972.
    p. 6-10.

38. National Bureau of Standards.  Washington, D.  C.  Technical Note 585.  January 1972 .
    p. 26-31.

39. National Bureau of Standards .  Washington, D.  C.  Technical Note 585.  January 1972.
    p. 11-25.

40. National Bureau of Standards.  Washington, D.  C.  Technical Note 585.  January 1972.
    p. 32-34.

41.  National Bureau of Standards.  Washington, D.  C.  Technical Note 505.  October 1969.
    p. 11.

42. National Bureau of Standards.  Washington, D .  C.  Technical Note 585 .  January 1972.
    p. 35-40.

43. Hanst.P.L. Spectroscopic Methods for Air Pollution Measurement.  In:  Advances in
    Environmental Science and Technology, J. N. Pitts and R. L. Metcalf, eds.  New York,
    John Wiley and Sons, Inc.  1971.

44. Atshuller, A. P.  Gas Chromatography in Air Pollution Studies.  J. Gas  Chromatog.
    1: 6-20, 1963

45. Ludwig, C.  B. , K. Bartle, and M. Griggs.  Study of Air Pollutant Detection by Remote
    Sensors. San Diego, California.  Prepared for  NASA by General Dynamics Corp.
    NTIS Publication number N69-31961.  Springfield, Va.  July 1971.

46. Federal Register.  38(135): 18985-19000,  July 16, 1973 .

                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
                                                            3. RECIPIENT'S ACCESSION NO.
  Progress  in Instrumentation and Techniques  For
  Measurement of Air Pollution
                                            5. REPORT DATE

                                             January 1Q74
                                            6. PERFORMING ORGANIZATION CODE
  Dr. A.  H.  Ellison
                                            8. PERFORMING ORGANIZATION REPORT NO.
  Office of Research and Development
  U.S. Environmental Protection Agency
  Research  Triangle Park, N.  C.  27711
                                            10. PROGRAM ELEMENT NO.
                                            11. CONTRACT/GRANT NO.
  Office of Research and Development
  U.S. Environmental Protection Agency
  Washington,  D.  C. 20460
                                            13. TYPE OF REPORT AND PERIOD COVERED
                                            14. SPONSORING AGENCY CODE
  This is  a  brief report on  instrumentation and  techniques for the measurement of
  air pollutants.  It covers  the techniques and  instrumentation that have  been
  promulgated  by EPA along with air pollution  standards, those that are  in use by
  EPA for  developing standards,  and those that are  being developed by  EPA  to meet
  current  or future needs.   Descriptions of these techniques are brief but reference
  to the detailed procedures  are given.
                                KEY WORDS AND DOCUMENT ANALYSIS
 Air Pollution
 Air Pollution
 Air Pollution
 Particulate  Matter
 Sulfur Oxides
 Nitrogen Oxides
 Photochemical Oxidants
                                               b.lDENTIFIERS/OPEN ENDED TERMS
                                                          c. COSATI Field/Group
Carbon monoxide
Hydrogeft  Sulfide
 Release unlimited
                                               19. SECURITY CLASS (ThisReport)
                                                          21. NO. OF PAGES
                               20. SECURITY CLASS (This page)
                                                          22. PRICE
EPA Form 2220-1 (9-73)