United States
Environmental Protection
Agency
Atmospheric Research and
Exposure Assessment Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-93/004 March 1993
EPA Project Summary
Evaluation of POHC and PIC
Screening Methods
Robert E. Adams, Ruby H. James, and David S. Weinberg
The application of a tiered approach
to the analysis of source emission
samples was evaluated for semivolatile
and nonvolatile organic compounds.
The analyses illustrate that in many
cases a combined approach will be use-
ful. If it is known that most of the toxic
compounds of interest are present in
the 100-300 °C boiling range then GC/
MS analysis will provide specific de-
tails and GRAY will give an indication
of the amount of high boiling nonvola-
tile material present. Alternately, HPLC/
UV may be needed for the analysis of
target POHCs of interest and screening
of the extract by TCO and GRAV may
be sufficient for the characterization of
other materials in the sample. When
PICs are to be determined, a chromato-
graphic procedure combined with mass
spectrometry will probably be required.
This Project Summary was devel-
oped by EPA's Atmospheric Research
and Exposure Assessment Laboratory,
Research Triangle Park, NC, to an-
nounce key findings of the research
project that Is fully documented as a
separate report of the same title (see
Project Report ordering Information at
back).
Introduction
The analysis of incinerator effluents of-
ten focuses on the analysis of one or a
few compounds as principal organic haz-
ardous constituents (POHCs) and on prod-
ucts of incomplete combustion (PICs) to
provide coverage for other compounds.
Comprehensive techniques that allow the
analysis of all organic compounds in an
effluent do not exist and would be costly
to apply. Recent studies have proposed a
risk-driven tiered-analysis protocol to char-
acterize combustion effluents. These pro-
cedures do not preclude the analysis of
targeted POHCs to measure destruction
and removal efficiency (ORE) or targeted
PICs such as polychlorinated dibenzo-p-
dioxins and dibenzofurans (PCDD/F) but
supplement them to provide extended cov-
erage to compounds of environmental in-
terest that may not be detected in a
directed analysis protocol.
Recent work proposed several standard
methods for screening purposes. Seven
protocols were proposed for screening
purposes:
• Gas chromatography/flame ionization
detection (GC/FID) screening for vola-
tile compounds
• GC/MS screening for volatile com-
pounds
• Soxhlet extraction for sample prepa-
ration
• Total chromatographable organic
(TCO) determination
• GC/MS for semivolatile compounds
• Gravimetric (GRAV) determination
• HPLC/UV screening method
The methods were from EPA SW-846 or
from other EPA documents. To these
methods we propose to add HPLC/MS as
a screening method.
The testing of screening methods in
this project has focused on the evaluation
of procedures to develop information on
the semivolatile and nonvolatile compo-
nents found in MM-5 sampling train
samples. We have applied Soxhlet ex-
traction, GRAV, TCO, GC/MS, HPLC/UV,
Printed on Recycled Paper
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and HPLC/MS to the analysis of MM-5
samples obtained from incinerators and
the analysis of laboratory-spiked samples
to determine the feasibility and applicabil-
ity of screening techniques.
Technical Approach
The testing of screening protocols for
the measurement of organic emissions
from incinerators can be divided into three
categories: volatile, semivolatile and non-
volatile. Volatile compounds are sampled
with bags, canisters, volatile organic sam-
pling train (VOST) and other techniques
designed to capture compounds that boil
below about 130 °C. Semivolatile and non-
volatile compounds are usually captured
with an MM-5 train. This study has con-
centrated on the semivolatile and non-
volatile categories of organic emissions.
Samples were obtained from incinerator
tests or were prepared as laboratory-
spiked samples.
Results and Discussion
The experiments conducted in this
project were tiered to apply the least com-
plicated and least expensive techniques
to samples first and then to apply the
more specific and thus more complex and
costly methods to develop data that would
indicate complete coverage of the organic
materials in the samples. The procedure
usually employed TCO analysis and GRAV
analysis prior to GC/MS, HPLC/UV or
HPLC/MS.
Gravimetric Analysis
A portion of each sample was taken for
GRAV analysis. The values for the MM-5
and ash samples varied from about 1 mg
to a high of 83 mg. The laboratory-spiked
samples all contained between 1 and 11
nng of GRAV material.
Total Chromatographable
Organic Analysis
Each sample was analyzed for TCO
with GC/FID. The MM-5 and ash samples
ranged from less than 1 mg to about 25
rng of TCO. The TCO levels in the spiked
samples were in the 1-to-10-mg range.
The data from the TCO and GRAV ex-
periments indicate that usually a more ex-
tensive analysis will be needed to aid in
the characterization of emission sources.
However, if a source has already been
extensively characterized these simple
analytical procedures may provide enough
information to monitor the emissions of
organic compounds into the atmosphere.
Gas Chromatography/Mass
Spectrometry (GC/MS)
We analyzed samples by GC/MS with
SW-846 Method 8270. Mass-spectromet-
ric analysis can identify compounds in
chromatographte peaks to determine if haz-
ardous substances are present. We also
analyzed laboratory-spiked XAD-2 resin
for compounds of environmental interest.
In most instances, recoveries are good
and relative percent differences of the du-
plicates are small. However, compounds
such as benzidine and 4,4'-methyl-
enedianiline present problems for analysis
by GC/MS at these spiking levels (100 u.g,
400 u.g, and 1000 |xg). Spikes of several
polynuclear aromatic compounds (PAHs)
were also analyzed by GC/MS.
A simplified version of SW-846 Method
8280 was employed to determine the de-
tectability of PCDD/F in the MM-5 samples.
Only two labelled PCDDs were added to
the sample extracts to serve as standards;
the surrogate standard was 13C12-2,3,7,8-
tetrachloro-p-dibenzodioxin and the inter-
nal standard was 37CI4-2,3,7,8-TCDp.
Matrix interferences made positive identi-
fication of PCDD/Fs uncertain. This analy-
sis indicated that when data for PCDD/Fs
are required, a simple screening proce-
dure is inadequate. A more complete
screen for PCDD/Fs requires extensive
and complex sample cleanup and analy-
sis techniques such as those described in
Method 8290.
Analysis by GC/MS gives data that can
characterize the organic emissions from a
source in the boiling range of 0 °C to
about 300 °C. The range of compounds
investigated in this project was from about
90 °C to 300 °C. Although excellent iden-
tification and adequate quantitation of tar-
get compounds can be made by GC/MS,
the range of coverage is small. Com-
pounds with high boiling points or com-
pounds that are thermally labile will not be
detected easily by GC/MS. Further analy-
sis by other techniques is needed to ex-
tend coverage to these compounds.
High Performance Liquid Chro-
matography with Ultraviolet De-
tection (HPLC/UV)
The MM-5 and ash samples were ana-
lyzed by HPLC/UV to determine if com-
pounds that were suitable for measurement
by HPLC/UV were present. A few peaks
were found in the samples, but identifica-
tion and thus quantification was not per-
formed.
These experiments indicate that HPLC/
UV is useful for the analysis of target
compounds where standards are avail-
able and interferences are not present.
However, screening of high-boiling-point,
polar, and thermally labile compounds from
emission sources will require a technique
that gives more specific identification and
allows for interferences to be minimized.
High Performance Liquid Chro-
matography with Mass Spec-
trometry (HPLC/MS)
Two approaches were used to examine
HPLC/MS analysis. We had a moving belt
interface available in our laboratory, and
the application of this type of interface to
samples that contain PAHs has been dem-
onstrated. Our efforts used PAH and other
compounds of environmental interest to
explore the use of this interface for screen-
ing purposes. We detected compounds of
molecular weights from 166 to 278. Inter-
ferences from the belt itself precluded com-
pounds of lower molecular weight from
this analysis. Investigations of MM-5
samples and laboratory-spiked samples
did not give positive results. The mea-
surement of compounds by moving belt
liquid chromatography/mass spectrometry
(LC/MS) is not amenable to quick or easy
screening techniques for environmental
analysis. In our second approach we sub-
mitted a sample containing eight com-
pounds to Vestec Corporation for analysis
by a Model 201 dedicated Thermospray
LC/MS coupled to a Compaq 386 com-
puter with Technivent software. This par-
ticle-beam interface was also of limited
usefulness for the sample that we submit-
ted. Other particle-beam interfaces or
Thermospray interfaces may give more
usable screening data for the evaluation
of emission sources.
The use of HPLC/MS in the character-
ization of emission sources offers the pos-
sibility of extending the coverage of
analysis to high-boiling-point, thermally la-
bile, and polar compounds. The techniques
are complex, and much development work
is needed to bring standard methods for
general analysis to routine use.
'U.S. Government Printing Office: 1993 — 750-071/60215
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Robert E. Adams, Ruby H. James, and David S. Weinberg are with Southern
Research Institute, Birmingham, AL 35255-5305.
Larry D. Johnson is the EPA Project Officer (see be tow).
The complete report, entitled "Evaluatbn of POHC and PIC Screening Methods,"
(Order No. PB93-144137; Cost: $19.50; subject to change) will be available only
from
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at
Atmospheric Research and Exposure Assessment Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
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