EPA-450/4-87-022
September 1987
URBAN AIR TOXICS
MONITORING PROGRAM
By
Engineering-Science, Inc.
One Harrison Park, Suite 200
401 Harrison Oaks Blvd.
Gary, North Carolina 27513
EPA Contract No. 68-02-3888
Project Officer: Dallas Safriet
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office Of Air And Radiation
Office Of Air Quality Planning And Standards
Research Triangle Park, North Carolina 27711
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This report has been reviewed by the Office of Air Quality Planning And Standards, U.S. Environmental
Protection Agency, and approved for publication as received from the contractor. Approval does not signify
that the contents necessarily reflect the views and policies of the Agency, neither does mention of trade
names or commercial products constitute endorsement or recommendation for use.
EPA-450/4-87-022
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URBAN AIR TOXICS
MONITORING PROGRAM
BACKGROUND
The Urban Air Toxics Monitoring Program was developed by EPA as a
way for state and local agencies to address the status of the air toxics
problem in their localities, and EPA strongly encourages agencies to
participate in the program. Following is a brief description of the
fundamentals of the air toxics program.
• What is the program? A national ambient screening study sponsored by
EPA to assist state and local agencies to assess the nature and mag-
nitude of their air toxics problems, primarily in urban areas.
• Why participate in the program? The monitoring program is in response
to the finding of potential increased health risks associated with
certain air toxic pollutants. Data generated from the study can be
used to determine the presence and levels of high risk substances and
the need for additional assessment.
• Where will the program take place? The program is primarily intended to
support data collection in major urban areas throughout the United
States. However, any area may participate if it wants to address a
particular area of concern.
• Who will take part in the program? The program is primarily designed
for participation by state and local air pollution control agencies
which are being encouraged by EPA to assess the nature and magnitude
of the air toxics problem.
• When will the program begin/end? The program began in late September,
1987 and will continue a minimum of one year after the starting date.
Depending on future funding allocation and interest shown by state
and local agencies, follow-on programs may be initiated for the next
2-3 years.
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URBAN AIR TOXICS PROGRAM DESCRIPTION
Recent studies have indicated a potential of elevated individual
lifetime cancer risks associated with certain air toxics often found in
urban areas. High risk urban areas result from complex pollutant mixtures
rather than from specific point sources which for the most part have been
identified and controlled. In response to results of these studies, the
Office of Air Quality Planning and Standards (OAQPS) is initiating a
screening study entitled Urban Air Toxics Monitoring Program. The primary
purpose of the Urban Air Toxics Monitoring Program is to support state
and local agency efforts to assess the nature and magnitude of the urban
air toxics problem in their respective areas.
EPA's objectives in promoting and supporting this program are:
o to provide estimates of annual concentrations of selected
air toxics,
o to provide information for prioritizing and planning future work
and sampling on a more in-depth and pollutant specific basis in
local areas,
o to provide a means to identify prevailing pollutants and possible
source types which may need further assessment, and
o to identify a means to evaluate and prioritize future air toxics
mitigation programs.
The program calls for state and local agency personnel to collect am-
bient air samples for subsequent analysis either by EPA or an EPA contractor
for specific toxic compounds (Table 1).
Three different types of ambient air samples are to be collected. The
first set of air toxics samples will be collected in stainless steel canis-
ters for 24-hour periods every 12 days for one year. After sample collec-
tion, the canisters are air shipped to a central laboratory for analysis.
The samples are analyzed for selected volatile organic compounds (VOCs)
by gas chromatography equipped with multi-detector capability. The
second set of samples will be collected in cartridges for determination
of aldehydes. The third set will be total suspended particulates (TSP)
collected from a high-volume air sampler for determination of selected
metals and benzo(a)pyrene [B(a)P].
In FY87, States participated in this program at a very reasonable
cost of $20K per site.* Nineteen state and local agencies (Table 2)
have already agreed to participate in this program.
* Cost in FY88 and beyond may vary.
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TABLE 1
URBAN AIR TOXICS MONITORING PROGRAM
COMPOUNDS TARGETED FOR ANALYSIS
CAS
Canister Sampling No.
Vinyl chloride3 75-01-4
1,3-Butadiene3 51-03-6
Benzene 71-43-2
Methylene chloride 75-09-2
Carbon tetrachloride 56-23-5
Ethlyene dichloride 107-06-2
Methyl chloride3 74-87-3
Trichloroethylene 79-01-6
Chloroform 67-66-3
Perch loroethylene 127-18-4
Chloroprene 126-99-8
1,4-Dichlorobenzene 106-46-7
Acetylene3 74-86-2
Toluene 108-88-3
Xylene 1330-20-7
n-Octane 111-65-9
1,3-Dichlorobenzene 54-17-3
1,2-Dichlorobenzene 95-50-1
l,l»l-Trichl oroethane 71-55-6
Propylene3 115-07-1
1,1,2-Trichl oroethane 79-00-5
1 ,1 ,2 ,2-Tetrachl oroethane 79-34-5
Styrene3 100-42-5
Bromomethane 74-83-9
Chlorobenzene 108-90-7
1,1-Dichloroethane 75-34-3
1,2-Dichloropropane 78-87-5
Dibromochloromethane 124-48-1
Bromodichloromethane 75-27-4
Chi oroethane 75-00-3
trans-l,2-Dichloroethylene 540-59-0
Bromochloromethane 74-97-5
trans-l,3-Dichloropropene 542-75-6
cis-1 ,3-Dichl oropropene 542-75-6
Bromoform 75-25-2
Add-on CAS
Cartridge No.
Formaldehyde 50-00-0
Acetaldehyde 75-07-0
Acrolein 107-02-8
Other Aldehydes
High- Volume CAS
Filter No.
Arsenicb 7440-38-2
Bariumd 7440-39-3
Beryl! iumd 7440-41-7
Cadmiumd 7440-43-9
Cobaltb 7440-48-4
Copperd 7440-50-8
Chromiumb 7440-47-3
Irond 7439-89-6
Manganesed 7439-96-5
Molybdenumd 7439-98-7
Nickeld 7440-02-0
Leadd 7439-92-1
Vanadiumd 7440-62-2
Zincd 7440-66-6
B(a)Pc 50-32-T
3 Potential of compounds coeluting on the proposed analytical column; therefore,
qualitative and quantitative identification may be limited.
° Determined by neutron activation analysis (NAA).
c Determined by thin layer chromatography (TLC).
d Determined by inductively coupled plasma (ICP) optical emission spectroscopy.
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TABLE 2
PRESENTLY COMMITTED SAMPLING SITES
FOR THE 1987 URBAN AIR
TOXICS MONITORING PROGRAM
U.S. EPA
REGION
I
IV
V
VI
URBAN AIR TOXICS MONITORING PROGRAM
EMPLOYING
SITE 24-HOUR EVACUATED CANISTER TECHNIQUE
Burlington, VT
Atlanta, GA
Birmingham, AL
Louisville, KY
Jacksonville, FL
Miami, FL
Chicago, IL
Cleveland, OH
Detroit, MI
Dearborn, MI
E. St. Louis (Sauget, IL)
Hammond, IN
Port Huron, MI
Midland, MI
East Lansing, MI
Dallas, TX
Houston, TX
Baton Rouge, LA
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Portland, OR
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SUPPORT TO PARTICIPATING AGENCIES
EPA and its central contractor will provide support to participating
state and local agencies through the following activities:
o provide all sampling equipment, including incidental supplies
such as canisters, aldehyde cartridges and high-volume sample
filters. The state or local agency is responsible for furnishing
and setting up a high-volume sampler for each site selected,
o set up all necessary equipment, except high-volume sampler, for sample
collection,
o train personnel on program operation and management (equipment
operation, sample collection, and sample shipment),
o provide sample analysis for the preselected pollutants,
o provide data results, and
o provide standard operating procedures (SOP) including Quality Assurance/
Quality Control (QA/QC) procedures for data collection and analysis.
Under EPA direction, the central contractor will bring the necessary
sampling train to each site, assemble the apparatus, instruct the sampling
technician on equipment operation and maintenance, and provide detailed
sample shipping information. Participating personnel will schedule a meeting
date and location for the contractor to set up and demonstrate the sampling
trains. Use of a central contractor for technical support for all partici-
pating agencies is expected to provide:
o good communications among participating States, EPA, and the
contractor,
o consistency of sampling practices,
o consistency of overall program operations, and
o increased accuracy through standardization of analytical procedures
in a central laboratory.
State and Local Responsibilities
All air toxics samples will be collected by participating agency
personnel. Participating agencies will be responsible for:
(1) selecting personnel and delegating responsibilities to collect samples,
(2) selecting sampling sites,
(3) maintaining sampling stations,
(4) collecting samples,
(5) shipping samples to laboratory for analysis,
(6) providing high-volume sampler, and
(7) receiving and reviewing data results.
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(1) Selecting Personnel and Delegating Responsibilities - Within the
framework of the existing agency operation, personnel should be selected and
delegated responsibilities for site selection, equipment and site maintenance,
sample handling, and data interpretation. Selected personnel will be respon-
sible for interaction with central contractor personnel to ensure program
objectives are met.
(2) Selecting Sampling Sites - To better characterize the air toxics
situation in their localities, participants are encouraged to select more
than one sampling site for each urban area. Two or more study sites would
provide a more definitive evaluation of the presence and magnitude of air
toxics in the areas of interest.
Monitoring site selection criteria depend upon the objectives of the
ambient monitoring program. If the agency is using the data as a secondary
tool to roughly assess what pollutants are present in the urban area, it
is recommended that the monitoring site should:
o represent as nearly as possible the typical ambient air
quality to which the population is exposed, and
o not be unduly dominated by a single source (mobile or stationary).
If an existing monitoring site meets these criteria, colocation of
the existing site with the urban air toxics monitoring site is recommended.
For a more detailed discussion of criteria for monitoring site selec-
tion, refer to Network Design and Site Exposure Criteria For Selected Non-
criteria Air PoTTuTants, EPA-450/4-84-022, September, 1984.
(3) Maintaining Sampling Stations - The central contractor will bring
air toxics sampling trains to each of the sites and instruct the sampling
operator on how to run them.
The toxics sampling train includes a heated manifold, valves, pumps,
flow controllers, timers, and associated hardware, packaged in a medium
size case. The central contractor wil1 provide instruction on initial
site preparation, sampler installation, operation/maintenance of sampling
system, and shipment of air toxics sample containers. A more detailed
explanation of the sampling train and analytical methods is contained in
the Appendix accompanying this document.
•
The air toxics sampling train should be housed in a room that is air-
conditioned during the-summer and heated during the winter to maintain a
constant room temperature of approximately 25°C. The high-volume sampler
should be located close by (perhaps on the roof of the same building). The
exhaust of the high-volume sampler should be properly vented or located so the
exhaust will not interfere with the inlet of the air toxics sampling train.
(4) Collecting Samples - During sampling, agency personnel will collect
24-hour integrated ambient air toxics samples in 6-liter SUMMA®-polished stain-
less steel canisters at participating sites. Evacuated canisters will be
filled nearly to atmospheric pressure using a mass flow controller to main-
tain a constant flow rate for 24 hours.
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Formaldehyde samples will be collected on dinitrophenylhydrazine (DNPH)-
coated cartridges at 1 L/min for 24 hours, using a critical orifice and a
vacuum pump. The canisters and the formaldehyde cartridges will be filled
from a common heated stainless steel manifold. Duplicate samples will also
be collected periodically.
TSP samples will be collected in the high-volume sampler simultaneously
with the canister and cartridge samples at each monitoring site.
(5) Shipping Samples - Filled sample canisters, high-volume sampler
filters, and formaldehyde cartridges will be identified and shipped to the
specified laboratory for analysis. Fresh empty canisters, filters, and
cartridges will be delivered to the participating agency prior to each
day that samples are scheduled to be taken. The central contractor will
furnish shipping instructions to site operators when the site is activated.
All samples should be shipped as soon as possible after collection.
(6) Providing High-Volume Air Sampler - The participating agency will be
required to provide a flow controlled high-volume sampler as part of the
Urban Air Toxics Monitoring Program. A flow controller is used with this
high-volume sampler so the air sample flow rate can be accurately controlled.
(7) Receiving and Reviewing Data Results - Upon receipt of the air
toxics samples, the central laboratory will analyze the samples for formal-
dehyde, other aldehydes, ketones and selected organics (Table 1) within a
few days. Results of these analyses will be reported quarterly and provided
to the participating agency. Results for the high-volume samples [B(a)P and
metals] will require more time due to the QA/QC validation program required
by the National Particulate Network (NPN) program. Results for B(a)P and
metals will be made available to the participating agencies approximately
six months after sample receipt.
NMOC/OPTIONAL AIR TOXICS PROGRAM
Many States are currently participating in the Non-methane Organic
Compound (NMOC) program. The current NMOC program is a continuation of the
NMOC Monitoring Network Program which focused on collection of total NMOC
data for ozone State Implementation Plan (SIP) development. EPA has
managed the current NMOC program for the past four summers (1984-87).
The purpose of the NMOC program is to collect total and speciated NMOC
and nitrogen oxides (NOX) data needed for ozone SIP modeling analyses.
In conducting the NMOC program, participating state and local agency
personnel collect samples in canisters and air freight them to Research
Triangle Park for analysis by a central contractor. Agencies are provided
with all necessary sampling equipment which they colocate with a NOX mon-
itor. NMOC canister samples are collected from 6-9:00 a.m. every weekday
for four months (June-September). FY87 costs for participating agencies
are $19K per site.* Participants of the ambient NMOC and optional air
toxics programs are listed in Table 3.
* Cost in FY88 and beyond may vary.
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TABLE 3
CURRENT PARTICIPANTS IN THE AMBIENT 3-HOUR NMOC/OPTIONAL AIR TOXICS
MONITORING PROGRAMS
U.S. EPA
REGION SITE
I Boston, MA
Hartford, CT
II New York, NY
Newark, NO
IV Atlanta, GA
Birmingham, AL
Louisville, KY
V Chicago, IL
Cincinnati , OH
VI Dallas, TX
Ft. Worth, TX
Houston, TX
El Paso, TX
Beaumont, TX
Longview, TX
Baton Rouge, LA
VII St. Louis, MO
VIII Salt Lake City, UT
IX San Francisco, CA
San Diego, CA
Fresno, CA
Bakersville, CA
Pittsburgh, CA
TOTAL NMOC
ANALYSIS
2
1
2
1
2
1
1
2
1
1
1
1
1
1
1
1
4 1
2
2
2
2
1
1
OPTIONAL
AIR TOXICS
2
2
1
2
1
1
2
1
Portland, OR
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The NMOC program is conducted in the same manner as the Urban Air
Toxics Monitoring Program. NMOC participants have the same responsibilities
as those taking part in the Urban Air Toxics Monitoring Program. Criteria
for delegating program responsibilities, selecting sampling sites, sampling
train operation/maintenance, sample shipment and data review are common to
participants of both programs.
Total NMOC concentrations are determined by the Preconcentration and
Direct Flame lonization Detection (PDFID) method. Some of the samples
are further speciated by the GC/FID method for QA/QC evaluation associated
with the NMOC monitoring program. In a supplementary limited effort to
characterize air toxics, some samples are also analyzed for toxics species
by a GC multi-detector procedure. This additional analytical program
will cost an additional $2K.
Limitations of the ambient NMOC/optional air toxics programs are:
o sampling is done only during the summer,
o only 3-hour samples are collected, and
o relatively few ambient air samples are analyzed for speciated
air toxics.
Recognizing these limitations, EPA encourages participation in the
more comprehensive Urban Air Toxics Monitoring Program, the results of which
should provide a more adequate data base on which to structure a state or
local agency air toxics program.
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APPENDIX
Sampling Techniques
Equipment
Sample Analysis
MASS SMCTJUM
10
0|
24-HOUR AIR TOXICS SAMPLER
HEATcD INLET LINE
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SAMPLING TECHNIQUES/EQUIPMENT
Urban air toxics samples are collected in 6-liter SUMMA® polished
canisters. Formaldehyde samples are collected in DNPH-coated cartridges.
Canister sampling for VOCs is an alternative to VOC collection on solid
sorbents (e.g., Tenax). Many VOCs which cannot be collected on Tenax
(due to high volatility, polarity, or reactivity) can be efficiently
collected and stored in canisters. Also, the canister contents may be
analyzed repeatedly. The central contractor will prepare and deliver all
sampling equipment (except high-volume sampler) to agency personnel.
Coated adsorbent cartridges are used as direct probes and traps for
sampling aldehydes in ambient air. Aldehyde sample collection is based
on the reaction of aldehydes with the acidified, DNPH-coated cartridges
to form a stable derivative which is then analyzed to determine the
concentration of the aldehydes.
SAMPLING TECHNIQUES
Evacuated Canister Sampling
The evacuated canister method requires no pump. Since the canister
is at a pressure lower than atmospheric, the air sample flows through
the heated manifold and mass flow controller and into the canister. The
electronic flow controller regulates and maintains a constant flow of
approximately 3 cc/min to the canister. Prior to sample collection, a
vacuum pump is activated by a timer to flush the heated manifold and par-
ticulate filter assembly with sample air. After a predetermined flushing
period, a second timer opens the magnelatch solenoid valve to allow
sample gas to enter the evacuated canister. Figure A-l shows a schematic of
the sampling system equipped with evacuated canisters and DNPH-coated car-
tridges. After sample collection, the canisters are returned to a central
laboratory for analysis of the ambient air samples. Collection of ambient
air samples in canisters provides a number of advantages, including:
o convenient integration of ambient samples over a specific period,
o ability to ship and store samples,
o remote sampling capability, with subsequent central laboratory analysis,
o unattended sample collection,
o analysis of samples from multiple sites with one analytical system, and
o collection of duplicate samples for assessment of sampling precision.
DNPH-Coated Cartridge Sampling
In the DNPH-coated cartridge sampling method, ambient air is drawn
through the heated manifold and into the cartridge by a vacuum pump. Ambient
A-l
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air is drawn through the cartridges for 24 hours at a constant flow rate
of 1 L/min. Periodically, duplicate samples are collected. This sampling
system is illustrated in Figure A-l.
After sampling, the DNPH-coated cartridges are capped at each end
and placed in a glass culture tube to minimize contamination. The culture
tubes are then shipped back to the central laboratory for analysis.
Filter Sampling
In the filter sampling method, ambient air is sampled by a high-
volume air sampler. TSPs are collected on the filter at a continuous air
flow rate of 1130-1700 L/min (40-60 ft3/min). After sample collection,
the glass fiber filter is placed in a clean, sealed container, shipped to
the central laboratory, and analyzed for metals and B(a)P.
SAMPLING EQUIPMENT
Ambient air is drawn into a sampling train which comprises an evacuated
canister(s) and DNPH-coated cartridge(s), and other components which include
an electronic flow controller that regulates the rate and duration of sampl-
ing. The canisters are treated internally by the "SUMMA" polishing process in
which a pure chrome/nickel oxide is formed on the interior surface. This
type of canister has been used in the past for sample'col lection and a number
of studies have been performed to demonstrate analyte stability in the canis-
ters.
The inlet system consists of a stainless steel filter to remove aero-
sols, and a stainless steel inlet line leading to a flow controller, pump,
canister(s) and cartridge(s). During operation, the flow controller main-
tains a constant flow rate to the evacuated canister(s). Sample air flows
into the initially evacuated canisters(s) and through the DNPH-coated car-
tridges for a 24-hour period.
For automatic operation, a programmable timer starts and stops the
air toxics sampler at the appropriate times for the intended sample period.
Prior to field use, the central contractor will test each sampling
system for pump contamination, leaks, and proper operation, and clean and
check the canisters for contamination.
SAMPLE ANALYSIS
The central contractor will arrange for analysis of the samples col-
lected and shipped to the specified laboratory by agency personnel. The
analytical laboratory will follow procedures prescribed by EPA for deter-
mination of preselected air toxics compounds. Organic toxic compounds will
be analyzed using gas chromatography, aldehydes will be analyzed using high
performance liquid chromatography (HPLC), metals will be analyzed using neu-
tron activation analysis (NAA) and inductively coupled plasma (ICP) spectro-
scopy and B(a)P will be analyzed by thin-layer chromatography. Table 4
outlines the sampling schedule and analytical procedures for each of the
programs discussed. Following is a brief description of the analytical
techniques for each program.
A-2
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HEATED INLET LINE
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FIGURE A-l.
SAMPLING ASSEMBLY FOR 24-HOUR
URBAN AIR TOXIC MONITORING PROGRAM
A-3
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3-HOUR TOTAL NMOC ANALYSIS
The 3-hour NMOC canister samples are analyzed by the PDFID method.
This method involves sample preconcentration-in a glass-beaded trap cryo-
genically cooled to approximately -186°C with liquid argon. The cryogeni-
cally-cooled trap simultaneously concentrates the NMOC while passing methane,
nitrogen, oxygen, etc. through the trap. The system is dynamically calibrated
so that the volume of sample passing through the trap does not have to be
measured, but must be precisely repeatable between the calibration and the
analytical phases.
After the fixed-volume air sample has been drawn through the trap, the
trap is heated and a helium carrier gas flow is diverted to pass through
the trap and into a flame ionization detector. The organic compounds pre-
viously collected in the trap volatilize and are carried into the FID, re-
sulting in a response peak(s). The 'area of the peak(s) is integrated and
the value is translated to concentration units by a previously obtained cali-
bration curve relating integrated peak areas with known concentrations of
a standard.
Concentrations of NMOC are reported in units of parts per million carbon
(ppmC), which for a specific compound is the concentration by volume (ppmv)
multiplied by the number of carbon atoms in the compound.
In addition to PDFID for all 3-hour NMOC samples, a minimum of 10% of
the canister samples will be speciated by a GC/FID equipped with a fused
silica capillary column. This serves as a QA/QC check of the ambient NMOC mon-
itoring program.
3-HOUR TOXICS ANALYSIS
The 3-hour air toxics samples are analyzed by a gas chromatograph
equipped with photoionization, electron capture and flame ionization
detectors. For separation and subsequent identification by the selective
detectors, the GC multi-detector technique relies on the analytes1 retention
times and selective detector peak response ratios for specific compounds.
The analytical system consists of a cryogenic trap, a GC column and se-
lective detectors. In the cryogenic trap, the air toxics are concentrated
prior to GC separation. The trap is then heated and the previously collected
organic compounds volatilize and are carried to the GC column by the carrier
gas. The GC column is temperature programmed for subambient cooling to pro-
vide improved resolution for the compounds of interest. After the column se-
parates the organics, the effluent gas stream containing the separated organics
enters a series of detectors consisting of electron capture, photoinization
and flame ionization. The individual detectors respond to the sample com-
ponents as a succession of peaks above a baseline on the chromatogram.
The area under the peak approximately quantifies the component, while
the time lapse between injection and emergence of the peak serves as a pre-
liminary identification. Detector peak response ratios are also used to
perform peak identification. Further confirmation and identification
will be performed on 20% of the total samples by gas chromatography/mass
spectroscopy (GC/MS). Concentrations of toxic species are reported in
units of ppb by volume (ppbv).
A-5
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24-HOUR URBAN AIR TOXICS ANALYSIS
TOXICS ANALYSIS
The 24-hour Urban Air Toxics Monitoring Program canisters are analyzed
with similar equipment previously described under the 3-hour air toxics analy-
sis. In summary, the organics (Table 1) in the canister are concentrated in
a cryogenic trap, revolatilized, separated on a fused silica capillary column
and monitored by PID, ECD, and FID electronic detectors. The combination of
the three detectors enables detection of different classes of organics which
normally could not be evaluated by a single detector. The air toxics in the
canister are qualitatively and quantitatively characterized through the GC
multi-detector procedure and confirmed by GC/MS.
ALDEHYDE ANALYSIS
Aldehydes are extracted from the DNPH-coated cartridges by gravity
feed elution of acetonitrile from a plastic syringe reservoir to a graduated
test tube or a volumetric flask. The eluate is then topped to a known volume.
The DNPH-formaldehyde derivative is determined by reverse phase HPLC with
an ultraviolet (UV) absorption detector. Formaldehyde and other carbonyl
compounds in the sample are identified and quantified by comparison of their
retention times and area counts with those of standard samples.
METAL ANALYSIS
Metals collected by the high-volume sampler are analyzed by inductively
coupled plasma(ICP) spectroscopy and neutron activation analysis. The detec-
tion limit and sensitivity of the analytical methods determine which technique
will be employed for specific metal analysis (Table 1). The ICP analytical
technique uses a plasma gas to ionize sample components at temperatures up to
10,000 K. In the ICP analysis, the sample is heated and cooled to produce
spectral lines representative of the sample components. The spectral lines
resolved in the spectrometer and the relative intensities of selected lines
of the elements are fed into a small computer. The computer calculates
concentrations based upon emission intensity of spectral lines. This tech-
nique allows simultaneous analysis of up to 50 elements per sample, thus
reducing cost and analytical time. Table 1 outlines those metals analyzed
by ICP.
Neutron activation analysis provides an accurate and sensitive means
of determining a large number of elements in a wide variety of samples. It
is a multi-element analytical technique based on selectively inducing radio-
activity in the sample's elements and measuring the radiation emitted by the
radioactive atoms. This procedure allows for qualitative identification
and quantitative determination of the elements from which the radiations
are measured. The radioactivation is accomplished by bombarding the ele-
ment's atoms with thermal neutrons. The energies and intensities of the
radiation are measured with a high-resolution detector coupled with an
analyzer system. Table 1 outlines the metals historically analyzed by
neutron activation analysis.
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B(A)P ANALYSIS
B(a)P and other polycyclic organic matter (POM) are captured on the
high-volume filter by drawing air through the filter at a rate of 1130-
1700 L/min (40-60 ft3/min). At the end of the sampling period, the
filter is retrieved and returned to a central laboratory for analysis.
During analysis, a portion of the filter (1-in. by 8-in. strip) is
immersed in cyclohexane and sonicated to extract the residual B(a)P. A
sample of this solution is spotted on a thin-layer plate and developed
in an ethanol/methylene chloride matrix to separate the dissolved B(a)P
from other POM's. The B(a)P is then quantified by ultraviolet fluorescence
spectrometry. The analytical range of the method is 0.4 to 8.0 ng/80 uL.
which corresponds to 0.18 to 3.6 ng/m3, assuming an air volume of 2000 m3.
DETECTION LIMITS
The analyses of the collected samples will identify those chemical
species (Table 1) which are present in concentrations which equal or
exceed the sensitivity of the proposed test methods. For those compounds
identified, an approximation of their concentrations will be obtained.
Historically, detection limits for GC/FID, GC/ECD, and GC/PID are 200 pg,
0.1 pg, and 1 pg, respectively. In general, the normal sampli ng/analysis
detection limits associated with each method are estimated as:
Approximate
Technique Pollutant Detection Limit
Evacuated Canister Organics 1.0 ng/m3
DNPH-Coated Cartridges Aldehydes 18.0 ng/m3
High-Volume Sampler Metals 4.0 ng/m3
High-Volume Sampler B(a)P 0.18 ng/m3
A-7
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1, REPORT NO. 2.
EPA-450/4-87-022
4. TITLE AND SUBTITLE
Urban Air Toxics Monitoring Program
7. AUTHOR(S)
9. PERFORMING ORGANIZATION NAME AND AOORESS
12. SPONSORING AGENCY NAME AND AOORESS
Office Of Air Quality Planning and Standar
U.S. Environmental Protection Agency (MD-1
Research Triangle Park, NC 27711
15. SUPPLEMENTARY NOTES
EPA Project Officer: Dallas Safriet
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
September 1987
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT
NO
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
13. TYPE OF REPORT AND PERIOD COVERED
ds
4) 14. SPONSORING AGENCY CODE
16. ABSTRACT
To assist States and local agencies, EPA has developed a program to
address the status of the air toxics problem in their localities. This
document provides a description of (1) the program, (2) support EPA
will provide to participating agencies and (3) the responsibilities of
State and local agencies.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b.lOENTIFI
Air Toxics
Urban Air Toxics
Ambient Monitoring
18. DISTRIBUTION STATEMENT 19. SECURT
20. SECURI-
ERS/OPEN ENDED TERMS C. COSATI Field/Group
PY CLASS (Tins Report! 21 NO OF PAGES
18
CY CLASS (Tins page I 22. PRICE
EPA Form 2220-1 (R«v. 4-77) PNKVIOUS EDITION is OBSOLETE
e<~i
w •
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DATE DUE
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