United States
Environmental Prot>- '
Agency
Industrial Environmenta : EPA 6(X.
Laboratory • /9
Research Triangle Park NC 2771 1
Measurement of PCB
Emissions from
Combustion Sources
Interagency
Energy/Environment
R&D Program Report
-------
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EPA-600/7-79-047
February 1979
Measurement of PCB Emissions
from Combustion Sources
by
P.L. Levins, C.E. Rechsteiner, and J.L. Stauffer
Arthur 0. Little, Inc.
Acorn Park
Cambridge, Massachusetts 02140
Contract No. 68-02-2150
T.D. 10102
Program Element No. INE624
EPA Project Officer: Larry D. Johnson
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
-------
TABLE OF CONTENTS
Page
LIST OF FIGURES iv
LIST OF TABLES v
I. INTRODUCTION 1
II. BACKGROUND 2
III. DEVELOPMENT OF AN ALTERNATIVE PCB ANALYSIS
METHOD 4
A. Discussion of GC/MS Method 4
B. Selection of MS Data Acquisition Masses . 5
C. GC Retention Time Criteria 7
D. Quantitative Calibration 11
IV. EVALUATION OF THE PCB ANALYSIS PROCEDURE ... 17
A. Calibration Procedure Evaluation .... 17
V. VERIFICATION OF METHOD 26
A. Evaluation of Test Samples 26
B. Recovery from Flyash 30
VI. CONCLUSION 38
VII. REFERENCES 39
Appendix A A-l
Appendix B B~*
Appendix C C-1
iii
-------
LIST OF FIGURES
Figure No. Page
1 Hypothetical Mass Spectra of PCB's 6
2 GC/MS Subset Mass Chromatogram of
Aroclor 1248 10
3 Analytical Mass Chromatograms for an
Aroclor 1248 Sample 12
4 GC/MS Subset Mass Chromatogram of
Aroclor 1242 Standard 19
5 GC/MS Subset Mass Chromatogram for
Aroclor 1254 Standard 20
6 GC/MS Subset Mass Chromatogram for
Aroclor 1260 Standard 21
7 GC/MS Subset Mass Chromatogram for
Waste Extract Mixture 28
8 a) GC/MS Subset Mass Chromatogram,
b-e) Single Ion Chromatograms for
Analytical Ions of Aroclor 1260 (326,
362, 394 and 428) for Waste Extract
Mixture Dosed with Aroclor 1260. Solid
Lines Delineate Relative Retention Time
Windows Used 29
9 a) GC/MS Subset Mass Chromatogram,
b-g) Single Ion Chromatograms for the
Analytical Ions of Aroclor 1242 (188,
224, 258, 292, 326) for Waste Extract
Mixture Dosed with Aroclor 1242. Arrows
Delineate the Relative Retention Time
Windows Used , 32
10 a) GC/MS Subset Mass Chromatogram,
b-d) Prominent Ion Chromatograms for
Analytical Ions 292, 326, 362 of Ferro-
Alloy Smelter Sample Dosed with Aroclor
1254. Arrows Delineate Relative Retention
Time Windows Used 33
11 GC/MS Subset Mass Chromatogram for Extracted
Flyash Sample Dosed with Aroclor 1254 (a)
and Aroclor 1254 Standard (b) 36
iv
-------
LIST OF TABLES
Table No. Page
1 Mass Spectrometry Data Acquisition
Subsets 7
2 Gas Chromatography RRT Windows Relative to
p,p'-DDE = 100 9
3 Aroclor 1248 Composition Analysis 13
4 Possible Aroclor Calibration Standards .... 14
5 PCS GC/MS Sensitivity Data: GC Areas .... 16
6 GC/MS Conditions 22
7 Analysis of Aroclor 1242 . 23
8 Analysis of Aroclor 1254 24
9 Anaylsis of Aroclor 1260 25
10 Organic Mixture Composition 27
11 Analysis of Mixture of Wastes and Waste
Extract 31
12 PCB Analysis of Ferroalloy Sample 34
13 PCB Analysis for Recovery of Aroclor 1254
in Dosed Flyash 37
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I. INTRODUCTION
The purpose of the contract award to Arthur D. Little, Inc., (EPA
Contract No. 68-02-2150) by the Process Measurements Branch of IERL/RTP
is to provide advanced organic sampling and analysis capabilities and
method development. The effort covered by the contract has been divided
into several areas, including the development of procedures for more
complete organic analyses which will be required in Level 2 (Technical
Directive 10202). As part of the effort in this category, EPA requested
an examination of the methods used for polychlorinated biphenyl (PCB)
analysis that would provide reliable data when applied to emissions from
combustion sources. Verification of a recommended PCB procedure was
part of the request.
In preparation of this report, three areas of effort have been de-
fined. 1) Pertinent publications have been reviewed to allow drafting of
a tentative PCB analysis procedure. 2) Laboratory experiments have
been conducted to test the tentative procedure using well characterized
reference materials. 3) Verification of the PCB analysis procedure has
been made using complex organic samples, representative of the types of
samples expected in environmental assessment studies. The recommended
procedure for PCB analysis is described in detail in Appendix A.
-------
II. BACKGROUND
The analysis and measurement of PCB emissions from combustion
sources encounters problems not dealt with in most reported PCB analy-
sis methods. Many reviews d"1*) have been published which present dif-
ferent analytical methodologies developed for PCB analysis and present
a good understanding of the PCB analysis problem. Of the methods typi-
cally utilized for PCB analyses, gas chromatography has been widely
implemented as a low cost, yet sensitive analytical technique.
Gas chromatographic analyses for PCB can be classified as using
either a pattern recognition approach or the measurement of individual
PCB peaks. The EPA Federal Register Method for PCB analysis in indus-
trial effluents^5) (Vol. 38, No. 78, pt. II) uses the pattern recogni-
tion approach utilizing conventional GC techniques with an electron cap-
ture detector. In this method the gas chromatogram of the sample is
examined for similarity to one of the known Aroclors, after a series of
clean-up steps, as appropriate for each sample. If a match is made, the
PCB content is reported as the suspected Aroclor. The several difficul-
ties associated with the pattern recognition approach have been recog-
nized by researchers conducting this type of analysis. In particular,
interferences introduced by co-eluting pesticides are especially common
for water and sediment samples. Elemental sulfur and other common
species such as phthalates are common interferences.
The quantitative method proposed by Webb and McCall ' was partially
incorporated into the Federal Register method as being recommended for
use only if the pattern recognition method seems to be nonapplicable.
The method of Webb and McCall measures each individual PCB peak, obvia-
ting the need for prior assessment of which PCB is present to determine
the proper calibration material. Even if there are interferences in the
chromato grams, use of individual peaks minimizes the errors caused by
non-PCB species.
Most of the EPA work on PCBs to date, has been on water and sediment
samples. As these methods have been applied to samples from combustion
sources, a variety of problems have been encountered. Samples from coal-
fired power plants and incinerators have been difficult to analyze for
PCBs. One of the problems Is that the PCBs exposed to a combustion pro-
cess have a substantially different pattern than the known Aroclor PCBs.
Most of these samples show a loss of the low end PCBs (mono-, di, and
trichloro) with a residual of the higher molecular weight PCBs (tetra-,
penta-, and hexachloro) . In addition, the nature of the GC inter-
ferences is different in these combustion effluent samples than In the
water and sediment samples.
To simplify the GC/ECD measurement procedure and increase the detec-
tion limit sensitivity for PCB1, Haile(7a) and Armour C8) have proposed
perchlorination of the PCBs using antimony pentachloride. This proce-
dure converts all of the individual PCB species to a single species,
decachlorobiphenyl (DCB) . Measurement of a single species can be a
-------
great improvement over the analysis of a complex mixture. However,
Armour cautions that the perchlorination method is only for confirmatory
purposes and to enhance the sensitivity of the analysis. In the Armour
procedure, the conventional pattern recognition approach must be used to
establish the identity of the sample prior to DCB formation. Since dif-
ferent amounts of DCB are produced from the individual PCBs, adjustment
factors ranging from 0.4 to 0.8 are required to convert DCB values to
quantities of specific Aroclor mixtures, and ultimately the accuracy of
the PCS measurement depends upon correct identification of the PCB
present*
Application of the perchlorination procedure for source measure-
ment of PCBs has been made to incinerator emissions (7a~9', with the
procedures described in detail in EPA document EPA-600/4-77-048^7a).
After perchchlorination, DCB was detected indicating the presence of
PCBs. However careful examination by GC/MS of aliquots of the original
samples, blanks, and incinerator fuels (10) showed that no PCBs were
present.
Because of the false positives problem and the difficulties in
accurate quantitative calibration, the perchlorination (DCB) procedure
is not sufficiently reliable to warrant use in measuring PCB emissions
from combustion sources. The Federal Register procedure for PCB mea-
surement in industrial effluent is not applicable because of the changes
in relative composition during combustion. Thus a new procedure was
needed for combustion sources.
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DEVELOPMENT OF AN ALTERNATIVE PCS ANALYSIS METHOD
A. Discussion of GC/MS Method
Automated gas chromatography/mass spectrometry (GC/MS) appeared to
offer the greatest potential for a sensitive quantitative analysis method
that would provide reliable PCB concentration data from the complete
range of environmental samples, including those from combustion sources.
Since chlorine in natural abundance exists as approximately a 3/1
ratio of 35C1/37C1, the Isotope clusters produced in the mass spectra
of PCBs provides a unique opportunity to both confirm identity and make
quantitative concentration measurements. The GC/MS method developed by
DudenbostelC12) and used in the EPA Region II laboratories makes use of
these factors. In their method, GC/MS data are collected in narrow mass
ranges corresponding to the molecular ion clusters of the mono-, di, etc.,
chlorobiphenyls. Selected spectra throughout the chromatogram are ex-
amined to verify that the data collected do correspond to PCBs according
to the isotope patterns expected in each mass range. The reconstructed
chromatogram is then pattern-matched to one of the Aroclors. Quantita-
tive measurement is based upon the ratio of the most intense peaks in
the sample and standard. The work by others, and in this report, is con-
centrated on the Aroclor PCBs, because they are the only PCB's that are
found with regularity in environmental studies in the United States.
While the Dudenbostel method^11' has many of the desirable specificity
features inherent in GC/MS, it still relies upon pattern recognition and
analysis of PCB as one of the Aroclors. This approach would not be ac-
ceptable for combustion source samples.
The paper by Eichelberger, Harris and Budde'12' lays the groundwork
for an alternate approach using GC/MS. The essence of their method is
to use PCB subset mass scanning with a particular mass chosen for each
of the monochloro heptachlorobiphenyl groups. They selected particu-
lar masses for each chlorobiphenyl so that there would be minimum overlap
between chloro groups. The approaches to using the method quantita-
tively were only lightly touched upon in that pap- . Quantitative
analysis was by pattern recognition and measurements as one of the Aro-
clors. Interference by pesticides, etc., was minimized by selection of
the subset masses. Although not stated explicitly in the paper, this
method clearly leads to the possibility of reporting PCBs in terms of
the amount of each chlorobiphenyl group (mono-, di-, etc.) present.
This kind of approach would overcome the difficulties found in combustion
source samples where the original Aroclor distribution patterns are
altered.
The approach developed in this study is based upon the excellent
groundwork developed by Webb and McCall<5), DudenbostelCIL)
Eichelberger, Harris and Budde<12>. The essence of the analysis method
is as follows:
-------
1) Acquire GC/MS data in PCB subset mass windows large enough
to encompass all of the isotope cluster(s).
2) Examine selected mass spectra to verify PCBs by their
chlorine isotope abundance patterns.
3) Generate mass chromatograms from a single mass chosen to
represent each chlorobiphenyl.
4) Integrate the areas of each mass chromatogram only in the
relative retention time (RRT) region corresponding to the
mono-, di, etc., chlorobiphenyls.
5) Quantify either from selected peaks in Aroclor reference
standards or with pure chlorobiphenyl isomers. The details
of the quantitative calibration are the subject of follow-on
studies, discussed in section IV. A complete description of
the analytical procedure is found in Appendix A.
B. Selection of MS Data Acquisition Masses
The previous EPA workX11*12) has clearly shown the increased sensi-
tivity to be gained for PCB analysis by using a selected subset masses
for each GC/MS scan. The question then becomes one of how to select
the correct mass or mass range for each chlorobiphenyl. We feel that
one must collect data over the full isotope cluster range in order to
be able to verify the PCB composition by means of the isotope abundance
pattern. The book by Safe and Hutzinger'13' provides a great deal of
information on the mass spectra of PCBs. Significant (> 5%) 37C1 iso-
tope peaks are found as follows for the various PCB groups.
PCB Group Significant Ions
Cli M, +2
C12 M, +2, 44
C13 M, +2, +4
Cljt M, 42, 44
C15 M, +2, 44, 46
C16 M, +2, 44, 46
C17 M, +2, 44, 46, +8
C18 M, 42, 44, 46, 48
C19 M, 42, 44, 46, 48
C110 M, 42, 44, 46, 48, 410
The initial data acquisition subset then should at least include
most of these ions. The mass spectrum of a chlorobiphenyl is dominated
by mass clusters at regions corresponding to the molecular ion (M*") and
M*--C1, M*--HC1, M*--C12- The K^-Cl and M^-HC1 clusters usually have only
about 10% relative intensity, whereas the itf" and lf*"-Cl^ ions are of about
equal intensity. The WT*"-C1 ion will be offset one mass lower than the
corresponding PCB isomer, while the M*"-HC1 and M^-ca.2 ions will be off-
set by two mass units from their corresponding PCB isomer. Simplified
-------
180
188 224
Analytical m/e's
2S8 292
326
362
394
1
1
fl *
1
, 1
1 1
h
,
1
1 1
II
l .
I
1 1
il
ii
-------
spectra of the PCB groups containing one to seven chlorines are shown
in Figure 1. In each case only the ion clusters due to M+, M^-C1 and
M+-C12 are shown, M+ and M+-C12 are shown as equal intensity and M+-C1
is shown at 50% intensity. From an examination of these data, a sub-
set mass range was chosen for each PCB group as shown in Table 1. The
ranges were chosen to include the fragment ions from higher PCBs and
enough of the isotope cluster to allow unambiguous identification of
the PCB.
The analytic method described in this report is applicable to
PCBs containing from one to ten chlorines. The samples analyzed during
the verification phase of this project were spiked with PCBs containing
no more than 8 chlorines. In the test samples, PCBs with higher chlo-
rine content were not found and, therefore, are not discussed in the
following sections.
Once the PCB identity has been confirmed, there are a variety of
ways of treating the data to obtain a quantitative measure of the PCB
groups. A single mass has been chosen which represents the most in-
tense mass in the molecular ion cluster with the minimum fragment ion
interference. When the GC retention window criteria are superimposed,
as discussed in the next section, it is only necessary to eliminate
(or minimize) the interferences from the one higher chloro group (i.e.,
tf^-Cl. The analytical masses felt to represent the best choices are
shown in Figure 1 and are listed in the last column of Table 1.
C. GC Retention Time Criteria
The M*-Cl2 fragment ion in the mass spectra of chlorinated biphenyls
could represent a difficult problem in the quantitative analysis of PCB
groups. The results of the careful work by Webb and McCallT6"*1*', how-
ever, present a means for overcoming this problem. A careful examina-
tion of their data reveals that there is no GC overlap between chlori-
nated biphenyls differing by two chlorines and only slight overlap by
biphenyls differing by one chlorine. The single chlorine overlap does
not present a serious problem for the GC/MS analysis, because the M+-C1
or -HC1 peaks are generally of only 10% relative intensity, and the
analytical masses can be chosen to minimize this problem.
From the Aroclor composition and GC data given by Webb and McCall(6)>
a tentative set of relative retention time (RRT) windows have been
chosen for each PCB group as shown in Table 2.
The PCB analysis procedure would then be to obtain the GC/MS data
in the subset mass ranges for the entire chromatogram. After PCB identi-
ties are confirmed by isotope ratio checking, mass chromatograms would
be obtained for each analytical mass. The area in the proper RRT window
would then be integrated for a measure of each PCB chloro group.
An example of this procedure can be seen from some preliminary work
conducted in the ADL laboratories. Figure 2 shows the reconstructed
chromatogram obtained from a GC/MS run using the subset mass ranges
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TABLE 1
Mass Spectrometry Data Acquisition Subsets
Total Analytical*
PCB Cluster H* m/e Range m/e m/e
5 188
7 224
7 258
7 292
** 6 318
** 7 326
9 362
9 394
9 428
9 464
11 498
Cli
C12
C13
Clj,
p,p'-DDE
C15
C16
C17
C18
Clg
Clio
188
222
256
290
316
324
358
392
426
460
494
186
220
254
288
316
322
356
392
426
460
494
- 190
- 226
- 260
- 294
- 321'
- 328'
- 364
- 400
- 434
- 468
- 504
40 m sec integration time per m/e.
**
p,p*-DDE (l,l-di[p-chlorophenyl] dichloroethylene) is used as
internal standard and its mass range may be combined with that
for pentachlorobiphenyl to meet the constraints of the data
system.
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TABLE 2
Gas Chromatography RRTWindows Relative to p,p'-DDE* = 100
Relative Retention
PCH Cluster Time (RRT) Window Analytical m/e
Clj 0(5) - 20 188
C12 15 35 224
C13
cu
cis
C16
C17
C18
C19
ciio
25
40
70
125
160
275
400
650
- 55
- 100
- 150
- 250
- 350
- 600
- 1000
- 1200
258
292
326
362
394
428
464
498
p,p'-DDE (l,l-di-[p-chlorophenyl[dichloroethylene) is used as
internal standard.
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RROCLOR 1248. 60 NG/UL, OV-1, 185 ISO, SMS
100
70
100 150
FIGURE 2: GC/MS Subset Mass Chromatogram of Aroclor 1248
RRTs for specific peaks labeled above peak
10
-------
chromatogram obtained from a GC/MS using the subset mpss ranges
given in Table 1. The RRT's were assigned bv comparison of this chroma-
togram to that published by Webb and McCall^ '. The chromatogram rep-
resents a 60 ng injection analyzed on a 2 m OV-1 column operated iso-
thermally at 185°C. The mass chromatograms constructed from each of
the analytical masses are shown in Figure 3. Each chromatogram is self-
normalized to 100.
The appropriate RRT windows for each chlorobiphenyl group are shown
on their respective mass chromatograms. One can see that using this
procedure eliminates the overlap problem from fragment ions appearing
in a particular mass chromatogram, due to another chlorobiphenyl. For
instance, the M-Cla peaks due to trichloro and tetrachlorobiphenyl,
respectively, are seen in the 188 and 224 mass chromatograms, but the
RRT window criteria eliminate these interferences.
These windows may have to be adjusted alightly for some samples
in order to properly integrate the GC areas. The PCS isotope pattern
criteria should be used in making these adjustments.
The chromatographic peak area found for each PCB group of this
Aroclor 1248 sample within the designated relative retention time window
are listed in Table 3. Comparison of the area % data found for this
test sample with the weight % data of Webb and McCall^6) for a different
Aroclor 1248 sample shows excellent agreement, using the assumption that
each PCB cluster has the same weight/response sensitivity. The close
agreement shown In Table 3 may be a fortuitous concidence in view of the
fact that two different samples of Aroclor 1242 are being compared. How-
ever, the closeness of the data suggests that relatively simple calibra-
tion procedures may yield accurate quantitative determinations.
D. Quantitative Calibration
Several approaches are possible for quantitative calibration of the
different PCB groups. For the simplest case, if one assumes that each
of the different PCB clusters has the same weight/response sensitivity,
then a single PCB species would allow calibration of all of the PCB
isomers found in a sample. A slightly more complex method would in-
volve preparation of a calibration mixture containing a single isomer
for each PCB group. This method assumes that all of the isomers within
a single PCB group have identical weight/response sensitivities.
A third, readily available method would be to use previously calibrated
Aroclor reference standards, such as those evaluated by Webb and McCall
for the GC/ECD analysis method, under conditions Identical to those
used with samples.
Since the PCBs are always found as complex isomer mixtures and the
various Aroclors have similar complexity, the third method offers self-
correcting advantages not available with the other two methods. Selec-
tion of either one or two isomer peaks for each chlorobiphenyl group
which are well defined by GC, have no other chlorobiphenyl overlap and
11
-------
100
100
IS)
t
I
Cl,
MflSS 188
r i Ji i i i i' I I [ ' I M I I ' I ' | ' I ' I i I M I | I I
50 100 150
MRSS 224
CL2
RRT
36
I i| I | I | I I I [ I I I I ' I I I ' | ' I
50 100 ISO
I
1
50 100
M/e
MflSS 258
50 , 100 150
Mr*
FIGURE 3 ANALYTICAL MASS CHROMATOGRAMS FOR AN AROCLOR 1248 SAMPLE
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TABLE 3
Aroclor 1248 Composition Analysis
PCB Group
Clj
C12
C13
CL,
C15
Cls
m/e
188
224
258
292
326
362
RRT Window
1-20
15-35
25-55
40-100
70-150
125-180a
Area
—
1452
17423
36896
11629
0
%D
(0)
2
26
55
17
0
Known %
0
1.2
24.7
57.8
19.8
0.4
a.
b.
Limit of chromatogram
Percentage each group was off the sum of the individual group
areas assuming that each PCB group has the same sensitivity.
c" Webb and McCall (reference 6, Table 4).
13
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TABLE 4
Possible Aroclor Calibration Standards
% RRT peak
PCS Cluster Aroclor RHT Peak8 is of Aroclor
Cl! CBP* 11 100
C12 1242 20, 21 11.3
C13 1242 37, 40 22.6
Cl^ 1254 47 6.2
C15 1254 84 17.3
C16 1254 174 8.4
C17 1260 280 11.0
C18 c
C19 d
C110 DCB** 1,100 100
Relative to p,p'-DDE = 100
b Webb and McCall (Ref. 6) (Appendix B)
c
Octachlorobiphenyl may be calibrated from Aroclor 1260 although
it is present at about 1% by weight. As an alternate method,
calibration against a pure Octachlorobiphenyl is recommended.
Nonachlorobiphenyl is not found in common Aroclors; calibration
against pure nonachlorobiphenyl is recommended. If nonachloro-
biphenyl is unavailable, assume equal sensitivity between octa-
chloro and nonachlorobiphenyl.
**
Decachlorobiphenyl
14
-------
whose abundance is reasonably high, or by using the entire envelope of
each PCB group, allows calibration under conditions of sample complexity
similar to that expected in actual analyses, as well as allowing routine
monitoring of all experimental equipment.
Table 4 lists a set of peaks abstracted from the work of Webb and
which could be used for PCB calibration. Other sets of peaks
could be chosen for calibration purposes, or even the entire RRT window
for each PCB group, as noted previously. Use of the entire RRT window
affords optimum self-correction by averaging the individual chlorobi-
phenyl isomer sensitivities, which may be of significance if the indi-
vidual isomer sensitivities show large variations. The other previously
proposed methods make the tacit assumption that the individual isomer
sensitivities do not vary too greatly. Use of a calibration based upon
the complete RRT window for any chlorobiphenyl group gives directly an
ensemble averaged calibration factor which should accurately describe
the average GC/MS system response to each chlorobiphenyl group.
Preliminary study of some individual chlorinated biphenyl isomers
have been conducted to evaluate the validity in GC/MS response between
isomers. A selection of pure compounds was obtained from RFR Corpora-
tion (1 Main Street, Hope, Rhode Island 02831). Certain of these were
selected on a random basis within PCB groups for initial study. Solu-
tions were prepared in benzene containing 5r-15 ug/mL. A 2-yL aliquot
of each solution was analyzed by GC/MS using a Finnigan 4000 with their
6100 data system. An OV-1 glass column was used and operated isother-
mally at either 185°C or 200°C depending on the isomer groups. A single
injection of each solution was made, and the data for each compound were
tabulated for comparison. A set of subset masses slightly different
from that recommended in the proposed method was used with an integra-
tion time of 20 msec/mass. The PCBs have a significant mass defect
(exact masses less than nominal mass) and the spectrometer was not tuned
to compensate for this fact. Thus, the data obtained are in some cases
from the sides of mass peaks and are not the optimum achievable.
The GC area response obtained for each of the isomers studied is
shown in Table 5. For this small set of data, standard deviations be-
tween 12% and 37% were found. Also, the average area/ng responses for
the different chloro groups vary by up to a factor of 2. As an extreme
case, consider the comparison of the tetrachlorobiphenyls. The
area/ng sensitivities for these species vary by a factor of 3. There-
fore any method which is based upon a single calibrating isomer is poten-
tially subject to sizeable error. Of the alternatives presented for
calibration, a calibration based upon the complete envelope of peaks
for each chloro-containing group seems to be the most attractive. The
procedure is essentially the same as that recommended by Webb and McCall
for the GC/ECD analysis of PCBs. Since the complexity of the calibration
samples approximates that found in environmental samples, the error due
to sensitivity differences between isomers Is minimized.
-------
Table 5
PCB GC/MS Sensitivity Data; GC Areas
RPC-27
RPC-30
RPC-33
RPC-38
RPC-41
RPC-47
RPC-51
Conq> ound
2 , 3 , 5-trichlorobiphenyl
2 ,2', 5-trichlorobiphenyl
2 ,4 , 5-trichlorobiphenyl
2,3,4, 5-tetrachlorobiphenyl
i i
2,2,4, 5-tetrachlorobiphenyl
2 , 3*, 4 i 5-tetrachlorobiphenyl
2 , 2', 3 , ' , s'-pentachlorobipheny 1
2, 2*, 3', , 6-pentachlorobiphenyl
2 , 2*, 4 , 4', 5 , S'-hexachlorobiphenyl
2 , 2*, 3 , 5 , 5', 6-hexachlorobiphenyl
Quantity (ng)
27.7
29.5
28.0
28.4
24.0
8.32
9.40
12.06
19.26
18.20
GC Area
206991
261941
191635
268218
284449
158440
135933
208174
167214
112066
avg. 7730
± 1040 (13%)
9400
11900
19000
avg. 13400
± 5000 (37%)
14500
17300
avg. 15900
± 2000 (12%)
8700
6200
avg. 7400
± 1800 (24%)
-------
IV. EVALUATION OF THE PCB ANALYSIS PROCEDURE
In the previous section, calibration of the different chlorobi-
phenyl groups using the entire RRT window for that group from a well
defined Aroclor reference material was recommended as the method of
choice. That procedure was evaluated in terms of its ability to give
consistent results over a period of time.
A. Calibration Procedure Evaluation
To evaluate the calibration procedure, samples of three Aroclor
reference materials, Aroclor 1242, Aroclor 1254, and Aroclor 1260, were
obtained from the batches analyzed by Webb^6^. The solutions were ob-
tained at a concentration of 1 mg Aroclor per 1 mL of solution in iso-
octane. Aliquots of each of the three Aroclor reference materials were
diluted to 20 yg/mL and p,p'-DDE was added to each to a level of 1 ug/mL.
Each Aroclor was then analyzed a minimum of six times over a period of
one week by the recommended GC/MS procedure using the conditions listed
in Table 6. After the completion of a run, the ion chromatograms for
each of the analytical ions and the internal standard were obtained.
Overlapping the ion chromatograms of PCBs differing by two chlorines
(e.g., M and M+-2C1) serves to clearly delineate the retention time win-
dows. For cases where the PCB group containing one more chlorine (MfCl)
is at a much higher concentration than M, the mass spectra of the peaks
in the ion chromatogram is used to pinpoint the location of RRT window
for M. The total ion chromatograms for the different Aroclors, Figures
4-6, show a pattern for these three Aroclors similar to those found by
GC/ECD methods. The results for the different Aroclors are shown in
Table 7 for Aroclor 1242, Table 8 for Aroclor 1254, and Table 9 for
Aroclor 1260.
The relative standard deviations for the analysis of each of the
Aroclor reference materials show excellent agreement. A majority of
the deviations are less than 3% and all are below 8%.
One may assess the validity of the equal weight/response sensiti-
vity method of calibration discussed in the previous section from
Tables 7, 8, and 9.
For some of the PCB chloro group, typically the major component(s),
the agreement between the known and found results was very good. How-
ever, the chloro groups present at less than 20% by weight can show
considerable error. Thus, using one group of chloro-containing PCBs,
such as the tetrachloro biphenyls, for calibration of the different
chlorobiphenyls may give acceptable results.
The method detailed in Appendix A, which uses calibration of the
specific chloro groups against a well characterized reference standard
will not be subject to the errors observed when the equal sensitivity
assumption is used. With this recommended analysis method more
17
-------
accurate concentration data can be obtained for a small increase in
analysis time. For the remaining sections, the recommended PCB pro-
cedure was used exclusively.
18
-------
I r | i i i i r I > i i i i i i i i I i i r i i i i i i n i i i i i | i i i i M i i i I i i i i I r 1 i \ i i i i i
I > i i i i i i i i I
too iso 2oa 250 300
FIGURE 4 GC/MS SUBSET MASS CHROMATOGRAM OF AROCLOR 1242 STANDARD
-------
to
o
IOQ ISO 2QQ 250 3QQ
FIGURE 5 GC/MS SUBSET MASS CHROMATOGRAM FOR AROCLOR 1254 STANDARD
-------
100
50
200
250
3DD
350
400
450
N>
100
500 550 6DO " " 650 ?b'o 750 800
FIGURE 6 GC/MS SUBSET MASS CHROMATOGRAM FOR AROCLOR 1260 STANDARD
-------
TABLE 6
GC/MS Conditions
I. Gas Chromatographic Conditions
a) Finnigan Model 9610 GC
b) 6-ft glass column packed with OV-1 coated
Supelcoport 100/120.
c) Multilinear temperature program
1) isothermal program at 185°C for 30 mln.
2) linear program from 185°-300° at 258C/min.
3) isothermal program at 300°C for 25 min.
d) 2-3 yL injections
II. Mass Spectrometric Condition
a) Finnigan Model 4000 mass spectrometer
b) mass range - 186-190, 220-226, 254-260, 288-294,
316-328, 356-364, 392-400, 426-434
c) integration time - " 50 msec/amu
d) electron multiplier - -1800V
e) electron energy - 50 eV
f) filament emission - 30 ma
g) scan rate - 3 sec/spectrum
22
-------
TABLE 7
Analysis of Aroclor 1242
% By
PCB
Cluster
Cli
C12
C13
Cli+
C15
Cl6
m/e
188
224
258
292
326
362
Known1
Results
1.1
16.95
39.19
31.83
9.64
.49
Weight2
Found
4.74
9.16
45.67
32.17
7.62
.63
Rel. Std.
Deviation
.0217
.0330
.0101
.0319
.0016
.0120
1 Webb & McCall, Ref. 6
Weight percent found by normalizing raw area ratio (PCB cluster
area/internal standard area) by the isotopic abundance of the
analytical ion and the molecular weight for the chloro group.
23
-------
TABLE 8
Analysis of Aroclor 1254
PCB
Cluster
C12
C13
Clk
m/e
224
258
292
Known1
Results
3
_3
13.80
% By2
Weight
Found
.17
1.03
21.68
Rel.Std.
Deviation
.003
.0056
.0106
C15 326 61.92 56.88 .0204
C16 362 23.28 19.08 .0019
C17 394 1.00 1.17 .0071
1 See Table 7
2 See Table 8
Webb reported components only >1%
24
-------
TABLE 9
Analysis of Aroclor 1260
PCB
Cluster
C12
Cl3
Cli,
C15
C16
C17
C18
m/e
224
258
292
326
362
394
428
Known1
Results
3
3
__3
11.52
46.14
34.84
6.10
% By
Weight2
Found
.20
.34
1.52
17.85
47.39
28.24
4.46
Rel. Std.
Deviation
.0009
.0029
.0032
.0776
.0152
• 0619
.0102
1 see Table 7
2 see Table 7
3 Webb reported only components >1%
25
-------
V. VERIFICATION OF METHOD
A. Evaluation of Test Samples
In order to demonstrate the application of the PCB procedure to
actual samples, two test mixtures were obtained, dosed with different
Aroclor materials and analyzed by the proposed procedure. One of the
test mixtures was a complex combination of several wastes and waste
extracts (see Table 10 for the mixture composition) while the other
mixture was the extract of a sample collected from a ferroalloy smelter.
Both samples had a wide variety of organic compounds ranging from low
mass to above mass 400.
The wastes and waste extracts comprising the first test sample are
listed in Table 10. These represent a complex system with numerous
potential interferences. The perchloroethylene waste did, in fact,
have some PCB content which added to the complexity of that sample.
Aliquots of the waste solution were dosed with either Aroclor 1242 or
Aroclor 1260 to a level of 10 yg per mL, and the internal standard
p,p'-DDE added to a level of 1 yg per mL prior to analysis. The amount
of dissolved material in this solution was about 0.28 g per mL, greatly
in excess of the amount of PCBs present. Figure 7 shows the reconstruc-
ted gas chromatogram (RGC) of the waste sample obtained from the inten-
sities of the ions in the mass ranges listed in Table 1 for each of the
PCB groups.
This sample contained no added Aroclor. With no preliminary sepa-
ration of the sample as is the case with the first sample, the normal
GC/ECD pattern recognition approach would have been unable to even indi-
cate the presence of PCBs in the sample. The presence of PCBs would be
even further obscured if ions had been acquired over the entire mass
range of interest, the normal GC/MS data acquisition mode.
Figure 8a shows the RGC for this mixture dosed with Aroclor 1260.
Since this sample consisted of primarily low molecular weight species,
the higher mass PCBs show relatively little inter*" ^rence from back-
ground species. The RRT windows used for each s^-.ies are shown in
Figures 8b-d, which is an RGC constructed from only the ions of analyti-
cal interest. Table lla lists the recovery data for the Aroclor 1260
dosed sample. For the major Aroclor containing components (Clg and Cly
biphenyls) the recoveries are within +5% and the relative standard
deviations are less than 3%. The other large component (Cls) has a
higher error (+10%) than for the two major components but it still
represents a reasonably accurate measurement. The minor Gig biphenyl
group shows large error (22%) and standard deviations (35%). but the
absolute level of this component was quite low (about 600 pg injected
or 1.4 x 10 12 mole), approaching the instrumental detection limit.
Measurement at such levels will show large errors for replicate runs
due to instrumental fluctuations.
26
-------
TABLE 10
Organic Mixture Composition
Styrene waste
mixture of aromatic hydrocarbons
API waste extract
mixture of aliphatic unsaturated
hydrocarbons and aromatic hydro-
carbons
Lucidol waste
mixture of a-methylstyrene, cumene,
cumyl alcohol and acetophenone
Perchloroethylene waste
hexachlorobutadiene, hexachloro-
benzene and a mixture of other
chlorinated hydrocarbons
Simulated coke waste
extract
mixture of phenol, cresol, amines
and benzoic acid
p-Toluene sulfonic acid
27
-------
Is,
00
300
' ' ' ' I '
350
FIGURE 7 GC/MS SUBSET MASS CHROMATOGRAM FOR WASTE EXTRACT MIXTURE
-------
KJ
VC
r-f-r- t- r-r-p*
100 I'll
50 100
?so 300 350 «0fl
',0 SUO SSI
FIGURE 8 a) GC/MS SUBSET MASS CHROMATOGRAM, b-fl) SINGLE ION CHROMATOGRAMS FOR
ANALYTICAL IONS OF AROCLOR 1260 (326, 362,394 AND 428) FOR WASTE EXTRACT
MIXTURE DOSED WITH AROCLOR 1260. SOLID LINES DELINEATE RELATIVE
RETENTION TIME WINDOWS USED
-------
When the above sample was dosed with Aroclor 1242 instead of Aro-
clor 1260, the interference due to the lower weight species became more
important. Figure 9 shows the RGC for the dosed sample using the set
of selective scanned masses (Figure 9a) and the chromatograms obtained
for each of the analytically important masses (Figures 9 b-g). The in-
terference at mass 188 (Clj biphenyl) swamps out the signal for that
chlorog group making it impossible to quantitate the level of monochloro-
biphenyl present. The other chloro groups from the added Aroclor 1242
show a decreasing amount of interference as the mass of the chloro group
increases. The results are tabulated in Table lib.
The second test mixture collected from a ferroalloy smelter repre-
sented a substantially different test for the PCB analysis procedure
than the previous mixture. This mixture contained aromatic hydrocarbons
and various oxygenated compounds ranging in mass to above 500, with
major components found in the 220-300 mass range. This range covers the
Cl^-Cli, PCBs, and the high levels of high mass species present a chal-
lenge for the determination of 01$ and higher PCBs not encountered with
the previous sample.
Examination of the ferroalloy extract prior to any Aroclor dosing
showed no detectable quantity of any PCBs. An aliquot of the extract
was then dosed with Aroclor 1254 to a level of 10 ug/mL, and repeti-
tively analyzed for PCBs. Figures 10 a-d show the various chromatograms
obtained for the ferroalloy sample extract dosed with Aroclor 1254. The
large variety of high mass species caused a nearly uniform total signal
during the elution of the PCBs, in contrast to the decreasing total
signal during the course of the PCB elution seen in the previous samples.
The recoveries for the various PCB groups are listed in Table 12.
The low recovery observed for the Clg biphenyl is in part due to
the high background observed for that ion throughout the chromatographic
run. Fluctuations in the background level near the RRT window for the
hexachloro group will cause error in the estimation of the background
level, with overestimation of the background level leading to low re-
coveries. However the recoveries found are acceptable for these low
level analyses, particularly since no pretreatmei >r separation proce-
dures were used.
B. Recovery from Flyash
As a final test of the recommended PCB procedure, a sample of flyash
was thoroughly extracted with methylene chloride, dosed with Aroclor
1254 and re-extracted with methylene chloride to ascertain the recovery
of PCB from a flyash sample. To 2 g of the pre-extracted flyash, 10 pg
of Aroclor 1254 in 50 mL of methylene chloride was added and the mixture
evaporated to dryness. The sample was then re-extracted with ten 10 mL
portions of methylene chloride. The ten portions were combined and
evaporated to 1 mL. The concentrated extract was dosed with 1 yg of
the internal standard material, p,p'-DDE, and analyzed via the recom-
mended procedure.
30
-------
TABLE 11
Analysis of Mixture of Wastes and Waste Extract
a) Mixture dosed with Aroclor 1260:
Mixture + Aroclor Aroclor
PCB Mixture Aroclor 1260
Cluster Background 1260 Found
(ug) (yg) (yg)
Cl,. .234 1.497 1.263
.351 4.919 4.568
1.059 4.739 3.680
.066 .813 .747
cle
Cl.
J
Cl,
Aroclor
1260
Added
(vg)
1.152
4.614
3.484
.610
Recovered
(%)
109.6
99.0
105.6
122.5
Relative
Standard
Deviation
.037
.015
.029
.353
b) Mixture dosed with Aroclor 1242
Mixture + Aroclor Aroclor
Relative
PCB
Cluster
Cli
C12
C13
Cl,,
C15
cic
Mixture
Background
tygj
—
—
—
.013
.234
.351
Aroclor
1242
(yg)
—
—
3.83
2.68
,905
.372
1242
Found
(yg)
—
5.85
3.83
2.67
.671
.021
1242
Added
(yg)
.11
1.70
3.92
3.18
.96
.05
Recovered
(%)
—
34.4*
97.7
84.0
69.9
42.0
Standard
Deviation
—
.090
.099
.050
.051
.255
*From reference 15, test sample was a mixture of each of the waste
ans waste extracts listed.
31
-------
H !• IH m SCO 3
H/C It*
K
i'li "fti 'MB in »
ivtnt
ta log fa ni aa m xo
n m IM tn m JOB
30B 3EB 408 4H
se IBB tso
Z6D JOB 3bO 4Bd 4Sfl
FIGURE 9 a) GC/MS SUBSET MASS CHROMATOGRAM, b-g) SINGLE ION CHROMATOGRAMS
FOR THE ANALYTICAL IONS OF AROCLOR 1242 (188.224,258.292,326) FOR
WASTE EXTRACT MIXTURE DOSED WITH AROCLOR 1242. ARROWS DELINEATE
THE RELATIVE RETENTION TIME WINDOWS USED
-------
SO tOO 160 2W 260 300 360 ««
too
60 tOO 160 200 260 300 360 «»
60 100 160 200 260
FIGURE 10 a) GC/MS SUBSET MASS CHROMATOGRAM. b-d) PROMINENT ION
CHROMATOGRAMS FOR ANALYTICAL IONS 292.326,362 OF
FERRO-ALLOY SMELTER SAMPLE DOSED WITH AROCLOR 1254.
ARROWS DELINEATE RELATIVE RETENTION TIME WINDOWS USED
33
-------
TABLE 12
PCS Analysis of Ferroalloy Sample1
PCB
Cluster2
Cl,,
C15
C16
C17
PCB Found
1.35
4.98
1.61
— an
Aroclor 1254
Added
1.38
6.19
2.33
.10
Recovered
97.8
80.5
69.1
••MB
1 Values reported are for 1 mL of sample volume.
2 €13 cluster was observed In reference material but Interferences
in the RRT window from other species prevent measurement.
34
-------
The RGC obtained from the extracted flyash sample was virtually
identical to the RGC obtained for the Aroclor 1254 reference material.
Figure 11 allows comparison of the Aroclor 1254 reference sample with
the re-extracted flyash sample. The recoveries were quite good, at
least 80% for the major PCB components (see Table 13). The Cla bi-
phenyl was seen in both the reference material and the dosed flyash
sample and the relative responses agreed within 5% for the reference
standard and the extracted flyash.
35
-------
150 200 260 300 35C
I I I I I I I | I I I I ' I ' I I [ I I I I ' M I ' [ I I ' I I I ' M | ' I ' I ' I r | I [ I | I I i | I M | ' I I I I I I I ' [ ' I
50 100 ISO 200 250 300 350
FIGURE 11 GC/MS SUBSET MASS CHROMATOGRAM FOR EXTRACTED FLY ASH
SAMPLE DOSED WITH AROCLOR 1254 (a) AND AROCLOR 1254
STANDARD (b)
-------
TABLE 13
PCS Analysis for Recovery of Aroclqr 1254 ia Dosed Flyash1
PCB Aroclor 1254
Cluster2 PCB Found Added Recovered
(Vg) (ug) (%)
CL* 1.17 1.38 84.8
C15 5.11 6.19 82.6
Cle 2.47 2.33 106.0
C17 — .16 —
Notes: See notes for this table on following page.
1 Values reported are for 1 ml of sample volume.
2 Cla cluster observed in both reference material and sample.
Agreement between the 013 cluster to internal standard ratio
for the reference and the standard is within 5%.
37
-------
VI. CONCLUSION
The analysis procedure for the measurement of PCB emissions from
combustion sources, Appendix A, has been tested for several representa-
tive samples. The recoveries found were quite good without any form of
extraction or sample cleanup. For complex samples, use of a prelimi-
nary separation scheme should improve the quantitative measurement of
PCBs by eliminating low mass interferences which can be quite sizeable.
Standard separation procedures such as those described in the Federal
Register Method for PCBs may be used for pretreatment of samples prior
to analysis of PCBs.
-------
VII. REFERENCES
1. J. Mieure, et al., Characterization of Polychlorinated Biphenyls,
in National Conference on Polychlorinated Biphenyls (November 19-21,
1975, Chicago, Illinois), published by Research Triangle Institute,
March 1976, NTIS No. PB-253248, page 84.
2. S. Safe, Overview of Identification and Spectroscopic Properties,
ibid, page 94.
3. Panel on Hazardous Trace Substances: Polychlorinated Biphenyls,
Environ, Rsch., .5, 247-362 (1972).
a. Properties, Production and Uses, ibid, p 258.
b. Analytical Methods, ibid, p 338.
4. 0. Hutzinger, _et jl., "The Chemistry of PCB's", CRC Press,
Cleveland, Ohio (1974).
5. Method for Polychlorinated Biphenyls (PCB's) in Industrial Effluents,
Fed. Reg. J8, No. 75, Pt. II (1973).
6. R. Webb and A. McCall, Quantitative Standards for Electron Capture
Gas Chromatography, J. Chromat. Aci., 11, 366 (1973).
7. a. C. Haile and E. Baladi, Methods for Determining the Total Poly-
chlorinated Biphenyl Emissions from Incineration and Capacitor-
and Transformer-filling Plants, Final Report on EPA Contract
No. 68-02-1780, Nov. 1977.
b. Personal communication, J. Clausen, TRW Systems Group,
January, 1977.
8. J. Armour, Quantitative Perchlorination of Polychlorinated Biphenyls
as a Method for Confirmatory Residue Measurement and Identification,
JAOAC, 56, 987 (1973).
9. W. Mitchell, QAB/EMSL/EPA/RTP, personal communication
February, 1977.
10. C. Haile, PCB Interlaboratory Verification Analysis, Midwest
Research Institute, Final Report on EPA Contract No. 68-02-1399,
December 27, 1976.
11. B. Dudenbostel, Tentative Method of Test for Polychlorinated
Biphenyls in Water, EPA, Region II, Edison, N.J., internal memo,
January 22, 1976.
12. J. Eichelberger, et al., Analysis of the Polychlorinated Biphenyls
Problem, Anal. Chem., 46, 227 (1974).
39
-------
References (continued)
13. S. Safe and 0. Hutzinger, Mass Spectrometry of Pesticides and
Pollutants, CRC Press, Cleveland, Ohio, 1973.
14. R. Webb and A. McCall, Identities of Polychlorinated Biphenyl
Isomers and Aroclors, JAOAC, 55, 746 (1972).
40
-------
APPENDIX A
Proposed Method
(Abbreviated)
Measurement of Polychlorinated Biphenyls
(PCBs) in Combustion Sources
1. Abstractof the Method
The method is designed primarily to address the problem of
measurement of PCB emissions from combustion sources, but
should be applicable to PCB measurements from any source.
The method uses an automated gas chromatograph/mass spectrom-
meter. Data are acquired in a select subset of masses and
integrated according to gas chromatographic retention time
criteria. Data are reported as quantity of monochloro-,
dichloro- decachlorobiphenyl.
2. Interferences
Interferences in the PCB analysis are minimized with this
procedure. Isotope abundance patterns are used to verify
the composition as a PCS. Selected mass chromatograms and
retention time windows provide a high degree of specificity
in the analysis of a specie as a PCB.
3. Sample Extraction
Sample extractions should be done using distilled-in-glass
pentane or methylene chloride (Burdick and Jackson). Samples
should be concentrated to 1.0 yl using a Kuderna-Danish evapo-
rator. If necessary to achieve sensitivity samples may be
further concentrated to 0.1 ml using a gentle stream of
nitrogen.
4. Sample Cleanup
It may be possible to analyze the extracted samples directly
without further cleanup. The analysis itself should be the
criteria for•determining the need for further cleanup as de-
scribed for the Standard EPA method for PCBs in industrial ef-
fluents. (5) If cleanup is required, use the florisil/silica
gel procedures described in the EPA method.
A-l
-------
5» Analysis
A. GC Conditions
Use a 2 m x 2 mm I.D., glass column containing any of several
phases. OV-1, OV-101, OV-17, Dexsil 300 and Dexsil 400 at 3% on
80/100 Chromosorb have all been used successfully for the PCB
analysis. Temperature programming from about 150°-280°C has been
used, but the chromatograms are more reproducible when run in the
isothermal mode. A temperature of 185 °C on OV-1 is good for the
Aroclors through 1248. A temperature of 200°C is used for the
higher Aroclors. A 2-5 yl sample size injection is made dependent
on the concentration in the sample. Use of less than 2 yl will
lead to poor reproducibility. The GC gas stream is diverted for
the first 30 sec allowing the solvent to elute and be vented and
then the diverter is closed and data acquisition initiated.
B. MS Conditions
Extract Conditions will depend on spectrometer type and condi-
tion. Care should be taken to calibrate the mass scale to accom-
modate the significant mass defect of the PCBs. It is recommended
that an Aroclor mixture be used in place of PC-43 (or other PFKs)
to construct an alternate mass calibration scale for the PCB analy-
sis. Set the mass ranges for data acquisition as follows:
PCB Group Range Analytical m/e
186 - 190 188
C12 200 - 226 224
C13 254 - 260 258
Cli* 288 - 294 292
C15 322 - 328 326
C16 356 - 364 362
C17 392 - 400 394
C18 426 - 434 428
C19 460 - 468 464
Cllo 494 - 504 498
Integration times will vary with instruments. A setting of 50-
64 msec/amu is recommended.
A-2
-------
6. Qualitative Identification of PCBs
A total chromatogram is constructed from the sum of all the mass
used in data acquisition. Individual mass spectra are obtained
at GC peak maxima. These spectra are examined to determine
whether the proper isotope abundance patterns are present for
the given chlorobiphenyl group.
7. Quantitative Measurement of PCB Groups
When the species have been confirmed as PCB's, individual mass
chromatograms are obtained for the analytical masses corres-
ponding to the PCB groups, 188, 224, 498. An Aroclor sample
such as Aroclor 1232 and Aroclor 1254 is used to establish a
relative retention time (RRT) scale using the data given by
Webb and McCall^6^. The area for each PCB group is integrated
over the RRT regions indicated below:
PCB Group Analytical m/e RRT Region
Cli 188 0(5) - 20
C12 224 15 - 35
C13 258 25 - 55
Cli, 292 40 - 100
C15 326 70 - 150
C16 363 125 - 250
C17 394 160 - 350
C18 428 275 - 600
C19 464 400 -1000
C110 498 650 -1200
The RRT windows may need to be adjusted slightly for proper
measurement of total areas. Use of these windows minimized
interferences from other PCB&.
Complete details of the quantitative calibration have not been
worked out at this time. It is tentatively recommended that
calibration be based upon specific GC peaks in Aroclor reference.
8. Sensitivity
The sensitivity of this method has not been established, but is
expected to be at least 0.1 ng/injected sample.
A-3
-------
APPENDIX B
Quantitative PCB Standards for
Electron Capture Gas Chromatography
by Ronald G. Webb and Ann C. McCall, Southeast Environmental Research Laboratory, National
Environmental Research Center—Corvallis Environmental Protection Agency, Athens, Georgia 30601
Abstract
The weight of PCB represented by each electron capture
gas chromatographic (EC-GC) peak in solutions of Aroclors
1221-1260 has been determined. The Aroclor samples from
which these solutions were prepared are proposed as quan-
titative PCB standards. Their compositions were determined
by elemental analysis, GC with a Coulson conductivity de-
tector, and combined GC MS. Retention times relative to
p.p -DDE are recommended to designate individual GC peaks
of PCB's. A table is given for each Aroclor showing the weight
percent of each EC-GC peak in the mixture. A procedure us-
ing Aroclors 1242,1254, and 1260 is recommended for analyz-
ing environmental samples containing more than one Aroclor
mixture. Stock solutions of the Aroclors in isooctane are
stable except when directly exposed to sunlight Ampoules
of the Aroclor solutions are offered.
Introduction
Quantitation of polychlorinated biphenyls (PCB's)
from electron capture (EC) chromatograms is compli-
cated because the EC detector responds differently to
each PCB isomer '1,2). Quantitation by direct com-
parison of an unknown EC chromatogram with those of
Aroclor standards is difficult because individual peaks
in environmental samples are sometimes obscured by
pesticide residues, are completely missing, or have
considerably different relative intensities.
To avoid these difficulties, Berg and co-workers (3)
have proposed that the PCB's in a sample be converted
to decachlorobiphenyl, and the EC signal from this
derivative be compared with that from conversion of
a known amount of Aroclor 1254 to decachlorobiphenyl.
This method appears to be ideally suited to a monitor-
ing program designed for rapid and sensitive measure-
ment of the total quantity of PCB's without regard to
composition. In many cases, this derivative approach
is undesirable because an extra analytical step is re-
quired and because any evidence of metabolism or
degradation of the sample is destroyed. The disadvan-
tages of both the direct comparison method and the
derivative method can be largely overcome by using
Aroclor standards in which the quantitative composi-
tion of each EC-GC peak is known. We have prepared
these standards and recommend procedures for their
use.
Experimental
Aroclor 1221 C, 72.94; H, 4.45; Cl, 22.74
1232 C, 64.44; H, 3.46; Cl, 31.96
1242 C, 54.64; H, 2.70; Cl, 42.85
1248 C, 49.50; H, 2.17; Cl, 48.54
1254 C. 44.10; H, 1.61; Cl, 54.33
1260 C. 38.18: H, 0.94; Cl, 60.97
The Food and Drug Administration provided the
primary standard p.p'-DDE, which was used as a re-
tention time standard and calibration standard for the
conductivity detector.
A Microtek 220 gas chromatograph was equipped
with a Coulson conductivity detector. The column was
a 6 ft x Vi in., o.d., glass U-shaped tube packed with 3%
SE-30 on 80/100 Gas Chrom Q. The carrier gas was
helium at a flow rate of 60 ml/min. All Aroclors were
chromatographed iaothermally; Aroclors 1221 and 1232
at 175*C; 1242, 1248 and 1254 at 185*C; and 1260 at
190*C. The chromatograms were quantitated by mea-
suring peak areas with either a planimeter or disc in-
tegrator.
A Microtek 220 gas chromatograph with Ni-63 EC
detector was operated at 15-30 V (DO and 275'C.
The column was a 6 ft x Vi in., o.d., glass U-shaped
tube packed with 3% SE-30 on 80/100 mesh Gas
Chrom Q. The carrier gas was nitrogen at 90 ml/min.
Aroclors 1221 through 1254 were chromatographed iso-
thermally at 200'C and Aroclor 1260 at 215"C.
An F&M 700 gas chromatograph with tritium EC
detector at 205'C was operated at a pulse interval of
15 microseconds. The coiled glass column was 8 ft z
Vi in., o.d., packed with 3% SE-30 on 80/100 Gas
Chrom Q. The carrier gas was 95% argon and 5%
methane at 80-100 ml/min. AH samples were chro-
matographed isothennally at 195° C.
Mass spectra (70 eV) were obtained on a Finnigan
1015-C quadrupole mass spectrometer interfaced with
a Gohlke separator to a modiifed Varian 1400 GC.
GC conditions were set to produce chromatograms
equivalent to those from EC-GC. The spectrometer was
controlled by a DEC PDP-8 computer, and spectra
were collected on magnetic tape and printed or plotted
under computer control.
'Mention of product* or companies doet not imply endorte-
ment by tk« Environmental Protection Agency.
The Monsanto Company" provided the Aroclor
samples, which were not marked with lot numbers.
Elemental analysis by Galbraith Laboratories, Knox-
ville, Tennessee, showed the following percent composi-
tions (average of triplicate analyses):
Reorinted with permission of the copyright" holder
1. Gregory, N. L., J. Chem. Soc. (B). 1968. 295 (1968).
2. Zitco. V., HuUinger. O.. and Safe, S.. Bull. Environ
Contain. Toxicol. 6,160 (1971).
3. Berg, O. W., Dioaady, P. L., and Rees, G. A. V. Bull
Environ. Contain. Toxicol. 7,338 (1972).
-------
Results and Discussion
The weight of PCB present in each GC peak of a
given Aroclor can be calculated from two pieces of
information:
1) the empirical formula of the compound
represented by the peak, and
2) the absolute amount of chlorine represented by
the peak
Combined GC/MS determines the first, and a GC
equipped with an electrolytic conductivity detector can
determine the second.
GC/MS examination of Aroclors showed that sev-
eral peaks were mixtures of PCB's with different num-
bers of chlorines. To estimate the composition of a GC
peak containing PCB's with different numbers of
chlorines, the following observation was used: equal
weights of two PCB's that differ only by one chlorine
give the same sum, within 25%, when the intensities
of all the signals from the molecular ion, or parent,
cluster, the parent-minus-one-chlorine cluster and par-
ent-minus-two-chlorine cluster of each PCB are added.
This rule was derived from a limited study of quadra-
pole mass spectra of a series of synthetic PCB's (4)
and may not hold for other types of spectrometers.
Figure 1 is the mass spectrum from an Aroclor 1242
GC peak that is a mixture of one or more trichloro-
biphenyls and one or more tetrachlorobiphenyls. The
molecular ion pattern at m/e 290-298 is typical of
four-chlorine molecules. These molecules lose one
chlorine, producing a three-chlorine fragment pattern
(parent-minus-one-chlorine) at m/e 255, 257, 259, and
261. However, between these signals, there is also a
strong three-chlorine pattern at m/e 256, 258, 260, and
262; this is the parent ion duster of the trichlorobi-
phenyl(s). The signals at m/e 220-224 are seen after
loss of two chlorines from the tetrachlorobiphenyl (the
trichlorobiphenyl (s) does not show a significant signal
for loss of one chlorine), and the signals at m/e 186
and 188 are seen after loss of two chlorines from tri-
chlorobiphenyl.
In Figure 1, the tetrachlorobiphenyl intensities
(peak heights) totaled 612 mm and the trichlorobi-
phenyl 304 mm. Tetrachlorobiphenyl is thus about two-
Jf
I V
tFtrnui MIVDI
170 10 ISO 200 210 22D ZB XO ZS 268 BO HO 250 JOO
Figure 1. A limited portion of the mass spectrum of a mix-
ture of tetrachlorobiphenyl(s) and trichlorobiphenyl(s) from
RRT peak 54 of Aroclor 1242 (See Figure 5). The abcissa is
marked in atomic mass units (m/e).
1242
"J?4
Figure 2. Gas chromatogram of Aroclor 1242 on SE-30 with
an electrolytic conductivity detector. The peak identification
numbers correspond to the retention time relative to p,p'-
DDE=100. From injection, at the arrow, to peak 146 was
about 20 min.
thirds of the mixture. These data were used to cal-
culate the average molecular weight of the material in
the GC peak.
The Coulson conductivity detector responds linearly
to chlorine. Linear response to PCB's was shown with
individual PCB isomers (4) containing one to six
chlorines, and the detector response was checked for
reproducibility several times each day with p,p'-DDE.
A typical Coulson chromatogram for 1242 is shown in
Figure 2. Peak resolution was not completely optimized
here or in the GC-MS work so that these separations
would be typical of those in the pesticide literature
(5-10). Other studies (4, 11, 12) have show that the
Aroclors are much more complicated than shown here,
but this resolution is adequate for routine analysis.
The area of each Aroclor peak was determined and
the weights (nanograms) of chlorine and PCB present
were calculated using the response of p,p'-DDE as
follows:
ng DDE injected
DDE peak area (cm=)
ngCl
4xat.wt. Cl ngCI
mol. wt. DDE ~ cm=
cm1
X PCB peak area (cm2) =ngCl
ngCl X;
Gram molecular weight
' No. of chlorines in molecule x 35.46 g
ngPCB
Tables I-VI present these results as the percent of
4. Webb, R. G., and McCall. Ann C., J. Assoc. Offic.
AnaL Chemists 55, 746 (1972).
5. Zitco, V., Bull. Environ. Con tarn. Toxicol. 6. 46-1
(1971).
6. Biros, F. J.. Walker, A. C., and Medberry, A., Bull
Environ. Contain. Toxicol. 5,317 (1970).
7. Grant, D. L., Phillips. W. E. J., and Villeneuve. A..
Bull. Environ. Contain. Toxicol. 5,317 (1970).
8. Holmes, D. C., Simmons, J. H-, and Tatton. J. O'G..
Nature 216, 227 (1967).
9. Bagley, G. E., Reichel, W. L., and Cromartie, E.. J.
Assoc. Offic. Anal. Chemists 53, 251 (1970).
10. Rote, J. W.. Murphy. P. G.. Bull. Environ. Contain.
To*icol. 6. 377 (1971).
11. Stalling, D. L., and Huckins, J. N.. J. Assoc. Offic
Anal. Chemists 54.801 (1971).
12. Sissons, D., and Welti, D., J. Chroraatog 60. 15 (1971).
JOURNAL OF CHROMATOGRAPHIC SCIENCE • VOL. 11
B-2
JULY 1973 • 3S7
-------
Table I. Composition of Aroclor 1221
RRT'
11
14
16
19
21
28
32
37
40
Total
Mean
Weight
Percent
31.8
19.3
10.1
2.8
20.8
5.4
1.4
1.7
93.3
Relative
Std. Dev.''
15.8
9.1
9.7
9.7
9.3
13.9
30.1
48.8
No. of
Chlorines1'
1
1
2
2
2
2~i
3 '
2H
3 !
3
3
85%
15%
10%
90%
'Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent. Overlapping peaks
that are quantitated as one peak are bracketed.
Standard deviation of seventeen results as a per-
centage of. the mean of the results.
From GC/MS data. Peaks containing mixtures of
isomers of different chlorine numbers are bracketed.
Table
RRT-
11
14
16
20
21
28
32
37
40
47
54
58
70
78
Total
1 1. Composition of Aroclor
Mean
Weight
Percent
16.2
9.9
7.1
17.8
9.6
3.9
6.8
6.4
4.2
3.4
2.6
4.6
1.7
94.2
Relative
Std. Dev."
3.4
2.5
6.8
2.4
3.4
4.7
2.5
2.7
4.1
3.4
3.7
3.1
7.5
1232
No. of
Chlorines0
1
1
2
2
2
2—40%
3J60%
3
3
3
4
3-^33%
4_J67%
4
4- 90%
5 110%
4
Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent. Overlapping peaks
that are quanti' .ted as one peak are bracketed.
Standard d- ation of four results as a means of the
results.
From GC/MS data. Peaks containing mixtures of
isumers of different chlorine numbers are bracketed.
total Aroclor weight represented by each GC peak.
The peaks are identified by their retention times rela-
tive to p,p'-DDE. We recommend that this be adopted
as a standard method for designating individual PCB
GC peaks. The separate percentages given for over-
lapping peaks were obtained by dividing the area with
a perpendicular to the baseline from the minimum point
between the two peaks. The accuracy of the Coulson
determinations was checked by comparing each Aro~
clor's calculated percent chlorine with its elemental
analysis. The amount found by Coulson GC was 98-
102% of the elemental analyses except for Aroclor
1221.
Seventeen analyses with 1221 were performed and
the average of the data was used to prepare Table I.
Willis and Addison (13) have recently reported semi-
quantitative values for the composition of Aroclor 1221.
Their analysis was based on EC-GC and flame ioniza-
tion GC. They found 12.7% biphenyl present and
about the same amounts of other materials as in Table
I. Willis and Addison accounted for 92.3% of the
weight of materials in 1221. If their 12.7% biphenyl
Table !
RRT"
11
16
21
28
32
37
40
47
54
58
70
78
84
98
104
125
146
Total
III. Composition of Aroclor
Mean
Weight Relative
Percent Std. Dev."
1.1
2.9
11.3
11.0
6.1
11.5
11.1
8.8
6.8
5.6
10.3
3.6
2.7
1.5
2.3
1.6
1.0
98.5
35.7
4.2
3.0
5.0
4.7
5.7
6.2
4.3
2.9
3.3
2.8
4.2
9.7
9.4
16.4
20.4
19.9
1242
No. of
Chlorines1"
1
2
2
2~ 25%
3J75%
3
3
3
4
3-j 33%
4 J 67%
4
4~, 90%
5J10%
4
5
5
5
5~~j 85%
6J15%
5~1 75%
6J25%
"Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent.
•"Standard deviation of six results as a percentage
of the mean of the results.
•'From GC/MS data. Peaks containing mixtures of
isomers of different chlorine numbers are bracketed.
13. Willis, D. E.. and Addison, R. F., J.
Board Can. 29,592 (1972).
Fisheries Res.
368 • JULY 1973
B-3
inilRNAI OF r.HROMATnRRttPHir
-------
is added to the PCB values in Table I, the weight
IK'rcvnt Aroclor is 106.0 A mixture composed of the
rdVs that Willis and Addison quantitated would con-
tain 19.6% by weight chlorine; the Coulson determina-
tions pave 22.9%; elemental analysis gave 22.7%.
When the data in Tables I-VI are compared to
Aroclor chromatograms from an EC detector operated
in the DC mode (Figures 3-8), peak size obviously is
not a valid indication of concentration. For example,
in Aroclor 1242 (Figure 5a) peaks 21, 28, 37, and 40
each represent about 11% of the mixture (See Table
III), but their areas differ by as much as 65%. There
are also major differences in peak ratios when the
Aroclors are measured with a detector operated in the
pulsed mode as shown in Figure 5b.
A Technique to Quanlitate PCB's in
Environmental Samples
The chromatograms of PCB's from environmental
samples usually show some evidence of degradation or
metabolism. A sample may contain a single partially
degraded Aroclor or a combination of Aroclors. Such
samples can be quantitated by using the standard Aro-
clors, the data in Tables I-VI, and some simple compu-
tation rules. The key principle is that the total amount
Table
RRT-
21
28
32
37
40
47
34
58
70
78
84
98
101
112
125
146
Total
IV. Composition of Aroclor
Mean
Weight
Percent
1.2
5.2
3.2
8.3
8.3
15.6
9.7
9.3
19.0
6.6
4.9
3.2
3.3
1.2
2.6
1.5
103.1
Relative
Std. Dev."
23.9
3.3
3.8
3.6
3.9
1.1
6.0
5.8
1.4
2.7
2.G
3.2
3.G
0.6
5.9
10.0
1248
No. of
Chlorines1
2
3
3
3
3-] 85%
4_J15%
4
3— 1 10%
4J90%
4
4-] 80%
5J20%
4
5
5
r ' 10%
5 j 90%
5
5~" 90%
6J10%
5") 85%
« J 15%
•Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent.
'Standard deviation of six results as a percentage of
the mean of the results.
• From GC MS data. Peaks containing mixtures of
isomers of different chlorine numbers are bracketed.
of PCB present is the sum of the amounts from all
the individual peaks.
To quantitate PCB's, chromatograph known
amounts of the standards. Measure the area for each
peak. Using the tables, determine the response factor
1221
2»
Figure 3. EC chromatogram of Aroclor 1221 chromatographed
on SE-30 with a Ni-63 detector operated in the DC mode. The
peak identification numbers correspond to the retention
time relative to p,p'-DDE=100.
Table
RRT"
47
54
58
70
84
98
104
125
146
160
174
COS
232
Total
V. Composition of Aroclor
Mean
Weight
Percent
6.2
2.9
1.4
13.2
17.3
7.5
13.6
15.0
10.4
1.3
8.4
1.8
1.0
100.0
Relative
Std. Dev."
3.7
2.6
2.8
2.7
1.9
5.3
3.8
2.4
2.7
8.4
5.3
18.G
26.1
1254
No. of
Chlorines1
4
4
4
4—, 25%
5 '75%
5
5
5
5~ 70%
6 '30%
5— 30%
6 :70%
6
G
G
7
"Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent.
"•Standard deviation of six results as a percentage of
the mean of the results.
Trom GC,MS data. Peaks containing mixtures of
isomers are bracketed.
JOURNAL OF CHROMATO&RAPHIC SCIENCE • VOL. 11
E-4
JULY 1973
369
-------
1232
1242
11
I
47 *•
j
'' ' '
Figure 4. EC chromatogram of Aroclor 1232 chromatographed
on SE-30 with a Ni-63 detector operated in the DC mode. The
peak identification numbers correspond to the retention time
relative to p.p'-DDE=100.
Rgure 5a. EC chromatogram of 03 ng Aroclor 1242 chromato-
graphed on SE-30 with a Ni-63 detector operated in the DC
mode. The peak identification numbers correspond to the
retention time relative to p,p'-DDE=100.
Table
RRT>
70
84
98
104
117
125
146
160
174
203
232
_244
280
332
372
448
528
Total
VI. Composition of Aroclor
Mean
Weight
Percent
2.7
4.7
3.8
3.3
12.3
14.1
4.9
12.4
9.3
9.8
11.0
4.2
4.0
.6
1.5
98.6
Relative
Std. Dev.»
6.3
1.6
3.5
6.7
3.3
3.6
2.2
2.7
4.0
3.4
2.4
5.0
8.6
25.3
10.2
1260
No. of
Chlorines*
5
5
1"
5 J60%
6J40%
6
5~|15%
6J85%
6
6~|50%
7J50%
6
en 10%
7J90%
ne
6 |10%
7J90%
7
7
8
8
8
"Retention time relative to p,p'-DDE=100. Measured
from first appearance of solvent. Overlapping- peaks
that are quantitated as one peak are bracketed.
''Standard deviation of six results as a mean of the
results.
'From GC MS data. Peaks containing mixtures of
isomers of different chlorine numbers are bracketed.
•'Composition determined at the center of peak 104.
• Composition determined at the center of peak 232.
1242
n
1 W"-.
• « m
Figure 5b. Pulsed mode EC chromatogram of Aroclor 1242
chromatographed on SE-30 with a tritium foil detector. The
peak identification numbers correspond to the retention time
relative to p,p'-DDE=100.
1248
Figure 6. EC chromatogram of Aroclor 1248 chromatographed
on SE-30 with a Ni-63 detector operated in the DC mode.
The peak identification numbers correspond to the retention
time relative to p,p'-DDE=100.
•nn
Illl V 1977
B-5
JOURNAL OF CHROMATOGRAPHIC SCIENCE • VOL 11
-------
1254
t*o m
Figure 7. EC chromatogram of Aroclor 1254 chromatographed
on SE-30 with a Ni-63 detector operated in the DC mode. The
peak identification numbers correspond to the retention time
relative to p.p'-DDE=100.
1260
r *• «'„
» 10
iV
ll
Figure 9a. DC mode EC chromatogram of a fat sample frc^i
a turkey that had been fed fishmeal contaminated with A-o-
clor 1242. The peak identification numbers correspond to the
retention time relative to p,p'-DDE=100.
Figure 9b. Standard Aroclor 1242 run under the same ccn-
ditions as Figure 9a.
Figure 8. EC chromatogram of Aroclor 1260 chromatographed
on SE-30 with a Ni-63 detector operated in the DC mode. The
peak identification numbers correspond to the retention time
relative to p,p'-DDE=100.
(ng PCB'cm-1 for each peak. Chromatograph the
sample and measure the area of each peak. Multiply
the area of each peak by the response factor for that
peak. Add the nanograms of PCB found in each peak
to obtain the total nanograms of PCB present.
Environmental Samples Containing Only One Aroclor
An example of a sample containing a single Aroclor
that is partially metabolized or degraded is seen in
Figure 9a. This is a chromatogram of fat extract from
a turkey that had been fed fishmeal contaminated with
Aroclor 1242. Figure 9b is standard Aroclor 1242 run
at the same conditions.
Several peaks present in the standard are com-
pletely missing in the sample, e.g., those at relative
retention times (RRT) 28 and 54. Some quantitation
methods do not make an adjustment when a peak is
missing from the sample. For example, one method
used to quantitate this sample compared the sum of
.ill the major sample peak heights with the sum of all
the peak heights in the standard. This approach as-
sumes that all the peaks present in the standard are
also present in the sample and that all PCB peaks
have the same electron capture response. Neither as-
sumption is valid. Quantitation by calculating the
amount of PCB present in each individual peak is the
solution of this missing peak problem. Calculation by
the sum-of-heights method indicates 0.28 ng of PCB
is present; the individual peak method gives 0.18 ng.
The standard Aroclor (Figure 9b) shows the peak
at RRT 84 separated only as a barely discernible
shoulder on peak 78; in the sample their proportions
are different and they elute as two separate peak?.
Since individual values are given for these peaks in
Table III, their individual values can be calculated.
In Figure 9, peaks 37 and 40 elute as a sincle peak
for both the sample and the standard. They are qu.in-
titated by combining the values in Table III. The
sample peak at RRT 203 was not quantitated because
no accurate comparison from the standard was avail-
able. Here, fortunately, the peak is only a small por-
tion of the total and can be ignored without seriously
biasing the results.
Peaks arising from pesticides can be mistaken for
PCB's; DDE and DDT were present in this sampl".
The PCB peaks eluting in these RRT regions are only
about 4% of Aroclor 1242 and can be omitted from the
total without causing major error. If there is any qup*-
tion about the presence of DDT, chlorinated naphtha-
lenes, chlorinated terphenyls, or other interferences,
then the total PCB residues computed by this method
can be confirmed by the derivative technique • 3, 14
Methods are also available to separate DDT-type pesti-
cides from PCB's if these results are necessary 3.
15-17).
Environmental Samples Containing
More Than One Aroclor
Most PCB contaminated samples of fi?h. watc-r.
and sediment contain residues of several Aroclor-.
Usually the sample chromatogram can simply }»• di-
vided into three separate areas and peaks in each arc-n
quantitated by using the appropriate Aroclor. Pf.-.k-
with RRT 11-70 are compared individually to cor-
14. Hutzinger. O.. Safe. S.. and Zitco. V.. Intern J. F:i
viron. Anal. Chem. 2.95 (1972».
15. Armour. Judith, and Burke. J.. J. Assoc Oiric. An,.
Chemists 53. 7C1 (1970).
1C. Burke. J. A., J. Assoc. Offic Anal. Clu-mi-i- 33 ^
(1972).
17. Leoni, V.. J. Chromatog. 62. 03 (1971).
JOURNAL OF CHROMATOGRAPH 1C SCIENCE • VOL. 11
B-6
JULY 1973
371
-------
responding peaks in Aroclor 1242, peaks 84-174 with
Aroclor 1254, and peaks with larger RRT with Aroclor
1260. These three Aroclors have been chosen for rou-
tine use as standards because they are the PCB's most
often found in environmental samples, they were sold
in largest quantities (particularly 1242 and 1254), and
their chromatograms include all the EC peaks normally
found in other Aroclor mixtures. In addition, this sys-
tem of dividing the chromatgojams generally matches
the changes in chlorine numbers; i.e., the peaks used
from the 1242 standard are the mono-through-tetra
chlorobiphenyls, the peaks calculated with 1254 are
penta- and hexachlorobiphenyls, and the peaks from
the 1260 standard are used to measure the hepta- and
octachlorobiphenyls.
Figure 10 is the chromatogram of a composite liver
extract of three bluegills from a PCB-contaminated
river. This sample obviously contains residues of sev-
eral Aroclors and was quantitated as described above.
However, some sample chromatograms require a more
rigorous division. A schematic of this division pro-
cedure is shown in Figure 11.
The logic of this division is based on several key
facts. Since Aroclor 1254 shows no appreciable peaks
(see Figure 7) before RRT 47, any peaks with a lower
RRT indicate the presence of some Aroclor of less
chlorine content. The most likely compound, from ox-
perience and commercial usage, is 1242. Ideally, all
peaks through RRT 78 would be calculated against
1242 (though many of them are present in TJ54 as
well), because peak 78 is unique to 1242 and not
ordinarily discernible in 1254 (compare Figures 5 and
6). However, when chromatographic resolution is not
optimum, mixtures of the two Aroclors may show peak
78 as only a shoulder on peak 84. Experiments with
known mixtures, described below, show that in this
case better results are obtained by making the division
at RRT 70 and treating peak 78 + 84 as though it were
all peak 84 from 1254.
A peak with RRT 117 is present in Aroclor 1260.
but absent from 1254. The presence or absence of this
peak in the sample chromatogram determines the stan-
dard used to quantitate the remaining peaks. Since
some columns do not resolve peak 117, the investiga-
tor will not always know that 1260 is present. Experi-
ments with mixtures show that calculations based on
1254 are adequate in this case.
All peaks of RRT larger than 174 are calculated
with Aroclor 1260 because the relative standard devia-
tions for these peaks are much lower in 1260 (Table
VI) than in 1254 (Table V). These rules were tested
with known-weight-ratio Aroclor mixtures that were
chromatographed through a low resolution column with
the GC detector operated in the pulsed mode. Table
VII gives the amount of FCB measured as a percentage
Figure 10. Division for quantitation of a DC mode EC chro-
matogram of PCB's from bluegill liver extract. The column
substrate was SE-30. The large peak at RRT 58 is an artifact
CM till tor
.«• tm f«r
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i. WT m ^
\ //
!• i
;**»
*!*•-*»*: tin
Table VII. Percent Recoveries of Aroclor Mixtures
Using Chromatogram Division Rules
Mixture
—1242
! 1254
~1242
1254
—1242
1254
~1242
I 1254
f-1242
1260
~1254
1260
—1254
1260
~1254
1260
"1242
! 1254
' 1260
Weight
Ratio
1
1
3
1
4
1
5
1
2
1
1.5
1
1
1.5
1
4
4
1
2
% Re-
covery
1242"
98
96
96
99
103'
102"-'
%Re-
covery
1242"
103
100
100
102
107»
104-1-'
%Re-
covery
1254*
109
103
105
99»
105"
% Re-
covery
1254'1
101
94
96
99='
103"
Figure 11. Chromatogram Division Flowchart.
"Peaks through RRT 70 calculated as 1242 (Table III).
"Peaks through RRT 84 calculated as 1242 (Table III'».
cPeaks through RRT 104 calculated as 1254 (Table V >.
•"Peaks through RRT 174 calculated as 1254 (Table V>.
'All other peaks calculated as 1260 (Table VI).
372 • JULY 1973
B-7
JOItRNAI OF rHRnMiTnri&flDuir
-------
of th.it injccli'd. Thcsr rcsulls were c.-ilculatcd using
pi';ik heights from the chromatograms. Tables III, V.
and VI. and the rules given above.
These computation rules and Tables I-VI should
also apply to chromatogram run on DC-200, OV-17
and OV-101 columns. However, QF-1 and OV-225
elute PCB's in a different order and the tables do not
apply.
Standard Solution Stability
To test the stability to UV light of Aroclor solu-
tions in concentrations typically used in GC analyses
118), several sealed glass ampoules of Aroclors 1242
and 1254 (10 ng/^1 isooctane) were prepared. Some
samples were stored in the dark, some were continu-
ously exposed two feet from a fluorescent light fixture
fitted with a decorative clear plastic shield, and sev-
eral were stored in a window that received several
hours of sunshine each day. No measurable changes
in peak ratios were observed by EC-GC in five obser-
vations over two months' time. However, after identi-
cal samples were exposed to direct sunlight for nine
dnys, some peak ratios changed significantly. For ex-
ample, in 1254 the apparent weight of material in RRT
peak 125 decreased by 50% and RRT peak 104 in-
creased by 15%. Therefore, direct exposure to sunlight
should be avoided.
Limited supplies of Aroclors 1242, 1254, and 1260
as dilute isooctane solutions in glass ampoules are
available from the authors as reference Aroclor kits.
Aroclors 1221, 1232, and 1248 are also available if
there is a special need.
Acknowledgment
The authors wish to thank Alfred Thruston for the
use of the turkey fat chromatograms and William Loy
for the fish liver chromatogram. •
Manuscript received October 2,1972
18. Safe. S.. and Hutzinger. O.. Nature 232. 641 (1971).
B-8
-------
Appendix C. Determination of Total PCB Emissions from Stationary Sources
(Draft Method)*
PART A. INDUSTRIAL, SEWAGE SLUDGE. AND
MUNICIPAL REFUSE INCINERATORS
1. Principle and Applicability
1.1 Principle. Gaseous and particulate PCBs are withdrawn isokinet-
ically from the source using a sampling train. The PCBs are collected in
the Florisil adsorbent tube and in the impingers in front of the adsorbent.
The total PCBs In the train are determined by perchlorination to decachloro-
biphenyl (DCB) and gas chromatographic determination of the DCB.
1.2 Applicability. This method is applicable for the determination
of PCB emissions (both vaporous and particulate) from industrial, sewage
sludge, and municipal refuse incinerators.
2. Range and Sensitivity
The range of the analytical method may be expanded considerably
through concentration and/or dilution. The total method sensitivity is also
highly dependent on the volume of gases sampled. However, the sensitivity of
the total method as described here is about 10 ng DCB for each analytical
replicate.
3. Interferences
Excessive quantities of acid-resistant organics may cause signifi-
cant interferences obscuring the analysis of DCB in the perchlorinated ex-
tracts. Blphenyl, although unlikely to be present in samples from combus-
tion sources, can form DCB in the perchlorination processes.
Throughout all stages of sample handling and analysis, care should
be taken to avoid contact of samples and extracts with synthetic organic
materials other than TFE® (polytetrafluoroethylene). Adhesives must not be
used to hold TFE® liners on lids, and lubricating and sealing greases must
not be used on any sample exposed portions of the sampling train.
4. Precision and Accuracy
From sampling with identical and paired sampling trains, the pre-
cision of the method has been determined to be 10 to 157. of the PCB concentra-
tion measured. Recovery efficiencies on source samples spiked with PCB com-
pounds ranged from 85 to 957..
(*) Method found in reference 7a
c-i
-------
5. Apparatus
5.1 Sampling Train. See Figure A-l; a series of four impingers with a
solid adsorbent trap between the third and fourth impingers. The train may
be constructed by adaptation from a Method 5 train. Descriptions of the
train components are contained in the following subsections.
5.1.1 Probe nozzle—Stainless steel (316) with sharp, tapered
leading edge. The angle of taper shall be £ 30 degrees and the taper shall
be on the outside to preserve a constant internal diameter. The probe noz-
zle shall be of the button-hook or elbow design, unless otherwise specified
by the Administrator. The wall thickness of the nozzle shall be less than
or equal to that of 20 gauge tubing, i.e., 0.165 cm (0.065 in.) and the dis-
tance from the tip of the nozzle to the first bend or point of disturbance
shall be at least two times the outside nozzle diameter. The nozzle shall
be constructed from seamless stainless steel tubing. Other configurations
and construction material may be used with approval from the Administrator.
5.1.2 Probe liner--Borosilicate or quartz glass equipped with a
connecting fitting that is capable of forming a leak-free, vacuum tight con-
nection without sealing greases; such as Kontes Glass Company "0" ring spher-
ical ground ball joints (model K-671300) or University Research Glassware SVL
teflon screw fittings.
A stainless steel (316) or water-cooled probe may be used for sam-
pling high temperature gases with approval from the Administrator. A probe
heating system may be used to prevent moisture condensation in the probe.
5.1.3 Pitot tube--Type S, or equivalent, attached to probe to
allow constant monitoring of the stack gas velocity. The face openings of
the pitot tube and the probe nozzle shall be adjacent and parallel to each
other but not necessarily on the same plane, during sampling. The free
space between the nozzle and pitot tube shall be at least 1.9 cm (0.75 in.).
The free space shall be set based on a 1.3 cm (0.5 in.) ID nozzle, which is
the largest size nozzle used.
The pitot tube must also meet the criteria specified in Method 2
and be calibrated according to the procedure in the calibration section of
that method.
5.1.4 Differential pressure gauge--Inclined manometer capable of
measuring velocity head to within 10% of the minimum measured value. Below
a differential pressure of 1.3 mm (0.05 In.) water gauge, micromanometers
with sensitivities of 0.013 mm (0.0005 in.) should be used. However,
C-2
-------
Thermometer"
Florisil Tube
Probe (f^
Reverse-Type
Pi tot Tube
Manometer
Control Box
I
Figure A-l. PCB Sampling Train for Incinerators
C-3
-------
micromanometers are not easily adaptable to field conditions and are not
easy to use with pulsating flow. Thus, other methods or devices acceptable
to the Administrator may be used when conditions warrant.
5.1.5 Impingers--Four impingers with connecting fittings able to
form leak-free, vacuum tight seals without sealant greases when connected to-
gether as shown in Figure A-l. The first and second impingers are of the
Greenburg-Smith design. The final two impingers are of the Greenburg-Smith
design modified by replacing the tip with a 1.3 cm (1/2 in.) 10 glass tube
extending to 1.3 cm (1/2 in.) from the bottom of the flask.
5.1.6 Solid adsorbent tube—Glass with connecting fittings able to
form leak-free, vacuum tight seals without sealant greases (Figure A-2). Ex-
clusive of connectors, the tube has a 2.2 cm inner diameter, is at least 10 cm
long, and has four deep indentations on the inlet end to aid in retaining the
adsorbent. Ground glass caps (or equivalent) must be provided to seal the
adsorbent-filled tube both prior to and following sampling.
5.1.7 Metering system--Vacuum gauge, leak-free pump, thermometers
capable of measuring temperature to within 3°C (~ 5°F), dry gas meter with
2% accuracy at the required sampling rate, and related equipment, or equiv-
alent, as required to maintain an isokinetic sampling rate and to determine
sample volume. When the metering system is used in conjunction with a pitot
tube, the system shall enable checks of isokinetic rates.
5.1.8 Barometer--Mercury, aneroid, or other barometers capable
of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg). In many
cases, the barometric reading may be obtained from a nearby weather bureau
station, in which case the station value shall be requested and an adjust-
ment for elevation differences shall be applied at a rate of -2.5 mm Hg
(0.1 in. Hg) per 30 m (100 ft) elevation increase.
5.2 Sample Recovery ,
5.2.1 Ground glass caps--To cap off adsorbent tube and the other
sample exposed portions of the train.
5.2.2 Teflon FBI® wash bottle--Two, 500 ml, Nalgene No. 0023A59
or equivalent.
5.2.3 Sample storage containers—Glass bottles, 1 liter, with
TFE®-lined screw caps.
5.2.4 Balance—Triple beam, Ohaus Model 7505 or equivalent.
5.2.5 Aluminum foil--Heavy duty.
C-4
-------
J 28/12
10cm
-2.5cm O.D.
-2.2cm I.D.
j28/12
Figure A-2. Florisil Adsorbent Tube
C-5
-------
5.2.6 Metal can--To recover used silica gel.
5.3 Analysis
5.3.1 Glass Soxhlet extractors--40 mi ID complete with 45/50 §
condenser, 24/40 <£ 250 ml round bottom flask, heating mantle for 250 ml
flask, and power transformer.
5.3.2 Teflon FEP wash bottle—Two, 500 ml, Nalgene No. 0023A59
or equivalent.
5.3.3 Separatory funnel--!,000 ml with TFE® stopcock.
5.3.4 Kuderna-Danish concentrators--500 ml.
5.3.5 Steam bath.
5.3.6 Separatory funnel—50 ml with TFE® stopcock.
5.3.7 Volumetric flask—25.0 ml, glass.
5.3.8 Volumetric flask—5.0 ml, glass.
5.3.9 Culture tubes—13 x 100 mm, glass with TFE®-lined screw caps,
5.3.10 Pipette--5.0 ml glass.
5.3.11 Aluminum block—Drilled to support culture tubes while
heating. ^
5.3.12 Hot plate—Capable of heating to 200°C.
5.3.13 Teflon®-glass syringe--! ml, Hamilton 1001 TLL or
equivalent with Teflon® needle.
5.3.14 Syrlnge--10 ul, Hamilton 701N or equivalent.
5.3.15 Gas chromatograph—Fitted with electron capture detector
capable of operation at 300°C and with 2 mm ID x 1.8 mm glass column packed
with 3% OV-210 on 100/120 mesh inert support (e.g., Supelcoport®).
5.3.16 Electric muffle .furnace--Capable of heating to 650°C.
5.3.17 Electric oven—Capable of heating to 150°C.
5.3.18 Disposable glass pipettes with bulbs--To aid transfer of
the extracts.
C-6
-------
5.3.19 Porcelain casserole—Capable of withstanding temperatures
as high as 650°C.
6. Reagents
6.1 Sampling
6.1.1 Florisil—Floridin Co., 30/60 mesh, Grade A. The Florisll
is cleaned by 8 hr Soxhlet extraction with hexane and then by drying for
8 hr in an oven at 110°C and is activated by heating to 650°C for 2 hr (not
to exceed 3 hr) in a muffle furnace. After allowing to cool to near 110°C
transfer the clean, active Florisil to a clean, hexane-uashed glass jar and
seal with a TFE®-lined lid. The Florisil should be stored at 110°C until
taken to the field for use. Florisil that has been stored more than 1 month
must be reactivated before use.
6.1.2 Glass wool—Cleaned by thorough rinsing with hexane, dried
In a 110CC oven, and stored in a hexane-washed glass jar with TFE®-lined
screw cap.
6.1.3 Water—Delonized, then glass-distilled, and stored in hexane-
rlnsed glass containers with TFE®-lined screw caps.
6.1.4 Silica gel--Indicating type, 6-16 mesh. If previously used,
dry at 175°C for 2 hr. New silica gel may be used as received.
6.1.5 Crushed ice.
6.2 Sample Recovery
6.2.1 Acetone—Pesticide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.2.2 Hexane--Pesticide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.3 Analysis
6.3.1 Hexane--Pestlcide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.3.2 Acetone--Pesticide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.3.3 Water—Deionized and then glass-distilled, stored in hexane-
rlnsed glass containers with TFE®-lined screw caps.
C-7
-------
6.3.4 Sodium sulfate (Ns^SO^)- -Anhydrous, granular. Clean by
overnight Soxhlet extraction with hexane, drying in a 110° C oven, and then
heating to 650°C for 2 hr. Store in 110°C oven or in glass Jar closed with
- lined screw cap.
6.3.5 Sulfuric acid (HjSO^)-- Concentrated, ACS reagent grade or
equivalent.
6.3.6 Antimony pentachloride (SbCl~) — Baker Analyzed Reagent or
equivalent.
6.3.7 Hydrochloric acid (HC1) solution- -ACS reagent grade or
equivalent, 50% in water.
6.3.8 Glass wool — Cleaned by thorough rinsing with hexane, dried
in a 110° C oven, and stored in a hexane-rinsed glass jar with TFE®- lined cap.
6.3.9 Decachlorobiphenyl — RFP Corp., No. RPC-60, or equivalent.
6.3.10 Compressed nitrogen- -Prepurif led.
6.3.11 Carborundum boiling stones — Hengar Co. No. 133-B or equiv-
alent, rinsed with hexane.
7. Procedure
Caution: Section 7.1.1 should be done in the laboratory.
^•1 Sampling. The sampling shall be conducted by competent personnel
experienced with this test procedure and cognizant of the constraints of the
analytical techniques for PCBs, particularly contamination problems.
7.1.1 Pretest preparation. All train components shall be main-
tained and calibrated according to the procedure described in APTD-0576,
unless otherwise specified herein.
7.1.1.1 Cleaning glassware. All glass parts of the train
upstream of and Including the adsorbent tube, should be cleaned as described
in Section 3A of the 1974 issue of "Manual of Analytical Methods for Analysis
of Pesticide Residues in Human and Environmental Samples." Special care
should be devoted to the removal of residual silicone grease sealants on
ground glass connections of used glassware. These grease residues should be
removed by soaking several hours in a chromic acid cleaning solution prior
to routine cleaning as described above.
C-8
-------
7.1.1.2 Solid adsorbent tube. Weigh 7.5 g of Florisil, ac-
tivated within the last 30 days and still warm from storage in a 110°C oven,
into the adsorbent tube (pre-rinsed with hexane) with a glass wool plug in
the downstream end. Place a second glass wool plug in the tube to hold the
sorbent in the tube. Cap both ends of the tube with ground glass caps. These
caps should not be removed until the tube is fitted to the train immediately
prior to sampling.
7.1.2 Preliminary determinations. Select the sampling site and
the minimum number of sampling points according to Method 1 or as specified
by the Administrator. Determine the stack pressure, temperature, and the
range of velocity heads using Method 2 and moisture content using Approxi-
mation Method 4 or its alternatives for the purpose of making isokinetic
sampling rate calculations. Estimates may be used. However, final results
will be based on actual measurements made during the test.
Determine the molecular weight of the stack gases using Method 3.
Select a nozzle size based on the maximum velocity head so that
isokinetic sampling can be maintained at a rate less than 0.75 cfm. It is
not necessary to change the nozzle size in order to maintain isokinetic
sampling rates. During the run, do not change the nozzle size.
Select a suitable probe length such that all traverse points can
be sampled. Consider sampling from opposite sides for large stacks to re-
duce the length of probes.
Select a sampling time appropriate for total method sensitivity
and the PCB concentration anticipated. Sampling times should generally fall
within a range of 2 to 4 hr.
It is recommended that a buzzer-timer be incorporated in the con-
trol box (see Figure 1) to alarm the operator to move the probe to the next
sampling point.
In some circumstances, e.g., short batch processes, it may be
necessary to sample through two or more batches to obtain sufficient sample
volume. In these cases, sampling should cease during loading/unloading of
the furnace.
7.1.3 Preparation of collection train. During preparation and
assembly of the sampling trcin, keep all train openings where contamination
can enter covered until Just prior to assembly or until sampling is about to
begin. Immediately prior to assembly, rinse all parts of the train upstream
of the adsorbent tube with hexane.
C-9
-------
Mark the probe with heat resistant tape or by some other method at points
indicating the proper distance into the stack or duct for each sampling
point.
Place 200 ml of water in each of the first two ispingers, and
leave the third impinger empty. CAUTION: do not use sealant greases in
assembling the train. If the preliminary moisture determination shows that
the stack gases are saturated or supersaturated, one or two additional empty
impingers should be added to the train between the third iepinger and the
Florisil tube. See Section 10.1. Place approximately 200 to 300 g or more,
if necessary, of silica gel in the last impinger. Weigh each impinger (stem
included) and record the weights on the impingers and on the data sheet.
Unless otherwise specified by the Administrator, attach a tempera-
ture probe to the metal sheath of the sampling probe so that the sensor is
at least 2.5 cm behind the nozzle and pitot tube and does not touch any
metal.
Assemble the train as shown in Figure A-l. Through all parts of
this method use of sealant greases such as stopcock grease to seal ground
glass joints must be avoided.
Place crushed ice around the impingers. """
7.1.4 Leak check procedure--After the sampling train has been as-
sembled, turn on and set (if applicable) the probe heating system(s) to reach
a temperature sufficient to avoid condensation in the probe. Allow time for
the temperature to stabilize. Leak check the train at the sampling site by
plugging the nozzle and pulling a 380 mm Hg (15 in. Hg) vacuum. A leakage
rate in excess of 47. of the average sampling rate of 0.0057 Q3/min (0.02 cfm)
whichever is less, is unacceptable.
The following leak check instruction for the sacpling train de-
scribed in AFTD-0576 and APTD-0581 may be helpful. Start the pump with by-
pass valve fully open and coarse adjust valve completely closed. Partially
open the coarse adjust valve and slowly close the bypass valve until 380 mm
Hg (15 in. Hg) vacuum is reached. Do not reverse direction of bypass valve.
This will cause water to back up into the probe. If 380 cc Hg (15 in. Hg)
is exceeded, either leak check at this higher vacuum or end the leak check
as described below and start over.
When the leak check is completed, first slowly renove the plug
from the inlet to the probe and immediately turn off the vacuum pump. This
prevents the water in the impingers from being forced backward into the
probe.
C-10
-------
Leak checks shall be conducted as described above prior to each
test run and at the completion of each test run. If leaks are found to be
In excess of the acceptable rate, the test will be considered invalid. To
reduce lost time due to leakage occurrences, it is recommended that leak
checks be conducted between port changes.
7.1.5 Train operation—During the sampling run, an isokinetic
sampling rate within 10%, or as specified by the Administrator, of true iso-
kinetic shall be maintained. During the run, do not change the nozzle or
any other part of the train in front of and including the Florisil tube.
For each run, record the data required on the data sheets. An
example is shown in Figure A-3. Be sure to record the initial dry gas meter
reading. Record the dry gas meter readings at the beginning and end of each
sampling time increment, when changes in flow rates are made, and when sam-
pling is halted. Take other data point readings at least once at each sam-
ple point during each time increment and additional readings when significant
changes (20% variation in velocity head readings) necessitate additional ad-
justments in flow rate. Be sure to level and zero the manometer.
Clean the portholes prior to the test run to minimize chance of
sampling deposited material. To begin sampling, remove the nozzle cap,
verify (if applicable) that the probe heater is working and up to tempera-
ture, and that the pitot tube and probe are properly positioned. Position
the nozzle at the first traverse point with the tip pointing directly into
the gas stream. Immediately start the pump and adjust the flow to isokinetic
conditions. Nomographs are available for sampling trains using type S pitot
tubes with 0.85 + 0.02 coefficients (C_), and when sampling in air or a stack
gas with equivalent density (molecular weight, M^, equal to 29+4), which
aid in the rapid adjustment of the isokinetic sampling rate without excessive
computations. APTD-0576 details the procedure for using these nomographs.
If C and Md are outside the above stated ranges, do not use the nomograph
unless appropriate steps are taken to compensate for the deviations.
When the stack is under significant negative pressure (height of
impinger stem), take care to close the coarse adjust valve before inserting
the probe into the stack to avoid water backing into the probe. If neces-
sary, the pump may be turned on with the coarse adjust valve closed.
When the probe is in position, block off the openings around the
probe and porthole to prevent unrepresentative dilution of the gas stream.
Traverse the stack cross section, as required by Method 1 or as
specified by the Administrator. To minimize chance of extracting deposited
material, be careful not to bump the probe nozzle into the stack walls when
sampling near the walls or when removing or inserting the probe through the
portholes.
C-ll
-------
FIELD DATA
PLANT.
DATE_
SAMPLING LOCATION.
SAMPLE TYPE
RUN NUMBER
OPERATOR
AMBIENT TEMPERATURE .
BAROMETRIC PRESSURE .
STATIC PRESSURE. IPSI_
FILTER NUMBER Is)
SCHEMATIC OF TRAVERSE POINT LAYOUT
PROBE LENGTH AND TYPE.
NOZZLE 1.0
ASSUMED MOISTURE.'.
SAMPLE BOX NUMBER
METER BOX NUMBER
METER AH,,
C FACTOR
PROBE HEATER SETTING _
HEATER BOX SETTING
REFERENCE ip
READ AND RECORD ALL DATA EVERY.
MINUTES
TRAVERSE
POINT
NUMBER
^S. CLOCK TIME
«jp*NXp3ctt
TIME.min \
' ~~~- ~
GAS METER READING
IVmi. II3
VELOCITY
HEAD
(APjl, m H20
ORIFICE PRESSURE
DIFFERENTIAL
IAHI. in. HjOl
DESIRED
ACTUAL
STACK
TEMPERATURE
•T...T
DRY GAS METER
TEMPERATURE
INLET
-------
During the test run, make periodic adjustments to keep the probe
temperature at the proper value. Add more ice and, if necessary, salt to
the ice bath, to maintain a temperature of less than 20°C (68"F) at the
impinger/silica gel outlet, to avoid excessive moisture losses. Also, peri-
odically check the level and zero of the manometer.
If the pressure drop across the train becomes high enough to make
isokinetic sampling difficult to maintain, the test run should be terminated.
Under no circumstances should the train be disassembled during a test run to
determine and correct causes of excessive pressure drops.
At the end of the sample run, turn off the pump, remove the probe
and nozzle from the stack, and record the final dry gas meter reading. Per-
form a leak check.* Calculate percent isokinetic (see calculation section)
to determine whether another test run should be made. If there is difficulty
in maintaining isokinetic rates due to source conditions, consult with the
Administrator for possible variance on the isokinetic rates.
7.1.6 Blank train—For each series of test runs, set up a blank
train in a manner identical to that described above, but with the nozzle
capped with aluminum foil and the exit end of the last impinger capped with
a ground glass cap. Allow the train to remain assembled for a period equiv-
alent to one test run. Recover the blank sample as described in Section 7.2.
7.2 Sample recovery. Proper cleanup procedure begins as soon as the
probe is removed from the stack at the end of the sampling period.
When the probe can be safely handled, wipe off all external par-
ticulate matter near the tip of the probe nozzle. Remove the probe from the
train and close off both ends with aluminum foil. Cap off the inlet to the
train with a ground glass cap.
Transfer the probe and impinger assembly to the cleanup area. This
area should be clean and protected from the wind so that the chances of con-
taminating or losing the sample will be minimized.
Inspect the train prior to and during disassembly and note any ab-
normal conditions. Treat the samples as follows:
7.2.1 Adsorbent tube—Remove the Florisil tube from the train and
cap it off with ground glass caps.
* With acceptability of the test run to be based on the same criterion as
In 7.1.4.
C-13
-------
7.2.2 Sample container No. I—Remove the first three impingers.
Wipe off the outside of each impinger to remove excessive water and other
debris, weigh (stem included), and record the weight on data sheet. Pour
the contents directly into container No. 1 and seal.
7.2.3 Sample container No. 2--Rinse each of the first three im-
pingers sequentially first with 30 ml acetone and then with 30 ml hexane,
and put the rinses into container No. 2. Quantitatively recover material
deposited in the probe using 100 ml acetone and then 100 ml hexane and add
these rinses to container No. 2 and seal.
7.2.4 Silica gel container--Remove the last impinger, wipe the
outside to remove excessive water and other debris, weigh (stem included),
and record weight on data sheet. Transfer the contents to the used silica
gel can.
7.3 Analysts. The analysis of the PCB samples should be conducted by
chemical personnel experienced in determinations of trace organics utilizing
sophisticated, instrumental techniques. All extract transfers should be
made quantitatively by rinsing the apparatus at least three times with hex-
ane and adding the rinses to the receiving container. A boiling stone should
be used in all evaporative steps to control "bumping."
7.3.1 Extraction
7.3.1.1 Adsorbent tube. Expel the entire contents of the
adsorbent tube directly onto a glass wool plug in the sample holder of a
Soxhlet extractor. Although no extraction thimble is required, a glass
thimble with a coarse-fritted bottom may be used.
Rinse the tube with 5 ml acetone and then with 15 ml hexane
and put these rinses into the extractor. Assemble the extraction apparatus
and extract the adsorbent with 170 ml hexane for at least 4 hr. The ex-
tractor should cy^cle 10 to 14 times per hour. After allowing the extrac-
tion apparatus to cool to ambient temperature, transfer the extract into a
Kuderna-Danish evaporator.
Evaporate the extract to about 5 ml on a steam bath and
allow the evaporator to cool to ambient temperature before disassembly.
Transfer the extract to a 50-ml separatory funnel and set the funnel aside.
7.3.1.2 Sample container No. 1. Transfer the aqueous sam-
ple to a 1,000-ml separatory funnel. Rinse the container with 20 ml acetone
and then with two 20-ml portions of hexane, adding the rinses to the sep-
aratory funnel.
C-14
-------
Extract the sample with three 100 ml portions of hexane,
transferring the sequential extracts to a Kuderna-Danish evaporator.
Evaporate the extract to about 5 ml and allow the evaporator
to cool to ambient temperature before disassembly. Filter the extract through
a micro column of anhydrous sodium sulfate into the 50 ml separatoty funnel
containing the corresponding Florisil extract. The micro column is prepared
by placing a small plug of glass wool in the bottom of the large portion of
a disposable pipette and then adding anhydrous sodium sulfate until the tube
is about half full.
7.3.1.3 Sample container No. 2. Transfer the organic solu-
tion into a 1,000 ml separatory funnel. Rinse the container with two 20 ml
portions of hexane and add the rinses to the separatory funnel. Wash the
sample with three 100 ml portions of water. Discard the aqueous layer and
transfer the organic layer to a Kuderna-Danish evaporator.
Evaporate the extract to about 5 ml and allow the evaporator
to cool to ambient temperature before disassembly. Filter the extract through
a micro column of anhydrous sodium sulfate into the SO ml separatory funnel
containing the corresponding Florisil and impinger extracts.
7.3.2 Extract cleanup--Clean the combined extracts (in SO ml
separatory funnel) by shaking with 5 ml concentrated sulfuric acid. Allow
the acid layer to separate and drain it off.
Transfer the hexane layer to a Kuderna-Danish evaporator and evap-
orate to about 5 ml. Allow the evaporator to cool to ambient temperature
before disassembly.
The extract should be essentially colorless. If it still shows
significant color, additional cleanup may be required before assaying for
PCBs. In this event, further clean the extract by liquid chromatography on
Florisil according to procedures described in Section 5A of the 1974 issue
of "Manual of Analytical Methods for Analysis of Pesticide Residues in Human
and Environmental Samples" Reduce the Florisil eluant to about 10 ml by
Kuderna-Danish evaporation techniques described above.
Transfer the cleaned extract to a 25 ml volumetric flask and di-
lute to volume with hexane. Pipette three 5.0 ml aliquots into culture
tubes for perchlorination. Retain the remaining 10 ml for later verifica-
tion, If required (see Section 10.2).
7*3*3 Extract perchlorination—Evaporate the aliquots in the cul-
ture tubes just to dryness with a gentle stream of dry nitrogen. If the ali-
quots will not evaporate to dryness, refer to Section 10.3 concerning special
cases. Add 0.2 ml antimony pentachloride with a 1 ml glass-TFE® syringe and
C-15
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seal the tube with a TFEf®-lined screw cap. Heat the reaction mixture to 160°C
for 2 hr by placing the tube in a hole in an aluminum block on a hot plate.
Allow the tube to cool to ambient room temperature before adding
about 2 ml of 50% HC1 in water to destroy residual antimony pentachloride.
This is a convenient "stopping point" in the perchlorination procedure.
Extract the reaction mixture by adding about 1 ml hexane to the
tube, shake, and allow layers to separate. Remove the upper hexane layer
with a disposable pipette and filter through a micro column of anhydrous
sodium sulfate directly into a 5 ml volumetric flask. Repeat the extraction
three times for a total of four extractions. Dilute the extract to volume
with hexane.
7.3.4 PCS determination—Assay the perchlorinated extracts for
decachlorobiphenyl (DCB) by gas chromatographic comparison with DCB stan-
dard solutions and correct this result for the DCB concentration determined
for the blank train. (Column temperature and carrier gas flow parameters
of 240°C and 30 ml/min, are typically appropriate. The concentrations of the
standard solutions should allow fairly close comparison with DCB in the sam-
ple extracts. Standards near 25 to 50 picograms/microliter may be appropriate.)
8. Calibration
Maintain a laboratory log of all calibrations.
8.1 Sampling Train
8.1.1 Probe nozzle--Using a micrometer, measure the inside dia-
meter of the nozzle to the nearest 0.025 mm (0.001 in.). Make three separate
measurements using different diameters each time and obtain the average of
the measurements. The difference between the high and low numbers shall not
exceed 0.1 mm (0.004 in.).
When nozzles become nicked, dented, or corroded, they shall be re-
shaped, sharpened, and recalibrated before use.
Each nozzle shall be permanently and uniquely identified.
8.1.2 Pitot tube--The pitot tube shall be calibrated according
to the procedure outlined in Method 2.
8.1.3 Dry gas meter and orifice meter—Both meters shall be cali-
brated according to the procedure outlined in APTD-0576. When diaphragm
C-16
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pumps with bypass valves are used, check for proper metering system design
by calibrating the dry gas meter at an additional flow rate of 0.0057 m^/min
(0.2 cfm) with the bypass valve fully opened and then with it fully closed.
If there is more than + 27, difference in flow rates when compared to the fully
closed position of the bypass valve, the system is not designed properly and
must be corrected.
8.1.4 Probe heater calibration—The probe heating system shall be
calibrated according to the procedure contained in APTD-0576. Probes con-
structed according to APTD-0581 need not be calibrated if the calibration
curves in APTD-0576 are used.
8.1.5 Temperature gauges--Calibrate dial and liquid filled bulb
thermometers against mercury-in-glass thermometers. Thermocouples should
be calibrated in constant temperature baths.
8.2 Analytical Apparatus
8.2.1 Gas chromatograph--Prepare a working curve from at least
five standard injections of different volumes of the DCB standard.
9. Calculations
Carry out calculations, retaining at least one extra decimal fig-
ure beyond that of the acquired data. Round off figures after final calcu-
lations .
9.1 Nomenclature
G_ = Corrected weight of DCB in nth perchlorinated aliquot (n = 1, 2, 3), pg.
G = Total weight of PCBs (as DCB) in sample, ug.
s
C = Concentration of PCBs in stack gas, ug/nr*, corrected to standard
conditions of 20°C, 760 mm Hg (68°F, 29.92 in. Hg) on dry basis.
A = Cross-sectional area of nozzle, nr (ft2).
n
B = Water vapor in the gas stream, proportion by volume.
W8
I = Percent of isokinetic sampling.
It. = Molecular weight of water, 18 g/g-mole (18 Ib/lb-mole).
Pbar = Barometric pressure at the sampling site, mm Hg (in. Hg).
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P_ = Absolute stack gas pressure) ran Hg (in. Hg).
s
P . = Standard absolute pressure, 760 mm Hg (29.92 in Hg).
R = Ideal gas constant, 0.06236 nm Hg-m3/°K-g-mole (21.83 in.
Hg-ft3/°R-lb-mole).
Tm = Absolute average dry gas meter temperature °K (°R).
T8 = Absolute average stack gas temperature °K (°R).
Tstd = standard absolute temperature, 293°K (528°R).
Vlc - Total volume of liquid collected in impingers and silica gel, ml.
volume of water collected equals the weight increase in grams
times 1 ml/gram
V = Volume of gas sample as measured by dry gas meter, dcm (dcf).
Vm(std) = Volume of gas sample measured by the dry gas meter corrected to
standard conditions, dscm (dscf).
V /stcj) = Volume of water vapor in the gas sample corrected to standard
conditions, son (scf).
Vt = Total volume of sample, ml.
V = Stack gas velocity, calculated by EPA Method 2, m/sec (ft/sec).
S
AH = Average pressure differential across the orifice meter, mm
(in. H20).
pw" = Density of water, 1 g/ml (0.00220 Ib/ml).
6 = Total Sampling time, min.
13.6 = Specific gravity of mercury.
60 = Sec/min.
100 - Conversion to percent.
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9.2 Average drygas meter temperature and average orifice pressure
drop. See data sheet (Figure A-3).
9.3 Pry gas volume. Correct the sample volume measured by the dry
gas meter to standard conditions [20°C, 760 mm Hg (68°F, 29.92 in. Hg)] by
using Equation A-l).
V«i(std) " v,
Lstd
ra
pbar
h AH
13.6
?8td
+ AH
= K V , bar 13.6
T
m
where K = 0.3655 °K/nm Hg for metric units
= 17.65 °R/in. Hg for English units
9»4 Volume of water vapor
Vw(std) B vic rr
RT8td
Equation A-l
Equation A-2
where K = 0.00134 m /ml for metric units
= 0.0472 ft3/ml for English units
9.5 Moisture content
BW8 -
Vstd)
Vm(std) + Vw(8td)
Equation A-3
If the liquid droplets are present in the gas stream assume the stream
to be saturated and use a psychrometric chart to obtain an approximation
of the moisture percentage.
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9.6 Concentration
9.6.1 Calculate the total PCB residue (as DCB) in the sample from
the weights of DCB in the perchlorinated aliquots according to Equation A-4.
G = 5(Gi + G2 + G3) Equation A-4
9.6.2 Concentration of PCBs (as DCB) in stack gas. Determine the
concentration of PCBs in the stack gas according to Equation A-5.
P
C = K 8 Equation A-5
8 v
m(std)
where K - 35.31 ft3/m3
9.7 Isokinetic variation
9.7.1 Calculations from raw data.
100 T8tKVlc+ (Vm/Tm) (Pbflr) + AH/13.6)]
60 8 vs P8 An
Equation A-6
where K = 0.00346 mm Hg-m3/ml-°K for metric units
= 0.00267 in. Hg-ft3/ml-°R for English units
9.7*2 Calculations from intermediate values.
r - Ts Vstd) *std 10°
6 An Ps 60
Ts Vm(std)
*s vs An (!~BWS) Equation A-7
where K = 4.323 for metric units
= 0.0944 for English units
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9.8 Acceptable results. The following range sets the limit on accept-
able isokinetic sampling results:
If 907. < I < 110%, the results are acceptable. If the results are
low in comparison to the standards and I is beyond the acceptable range, the
Administrator may option to accept the results.
10. Special Cases
10.1 Sampling moisture saturated or supersaturated stack gases. One
or two additional modified Greenburg-Smith impingers may be added to the
train between the third impinger and the Florisil tube to accommodate addi-
tional water collection when sampling high moisture gases. Throughout the
preparation, operation, and sample recovery from the train, these additional
impingers should be treated exactly like the third impinger.
10.2 PCS verification. It is recommended that an unperchlorinated
aliquot from at least one sample be subjected to GC/MS examination to verify
that PCB isomers are present.
To accomplish this, the unperchlorinated portion of each extract
is first screened by GO with the same chromatographic system used for DCB
determination except for a cooler column temperature, typically 165 to 200°C.
The elution patterns are compared with those of commercial PCB mixtures (in
hexane solution) to determine the most similar mixture.
After determining what PCB isomers are possible present, the sam-
ple is examined by GC/MS using multiple ion selection techniques for ions
characteristic of the molecular clusters of the PCBs possibly present.
10.3 Evaporation of extracts for perchlorination. For cases where the
extract will not evaporate to dryness or excessive PCB loss by volatiliza-
tion is suspected, the hexane may be removed by azeotrophic evaporation from
the hexane/chloroform mixture.
Add 3 ml of chloroform to the aliquot in the culture tube. Add
a boiling chip and concentrate by slow boiling in a water bath to 1 ml.
Repeat the chloroform addition and evaporation three times in order to remove
all residual hexane. Then further concentrate (slowly) to a volume of ap-
proximately 0.1 ml. Under no circumstances should the water bath tempera-
ture be permitted to exceed 76 C or the solvent be evaporated to dryness.
The final volume (0.1 ml) may be determined with sufficient accuracy by
comparison of .solvent level with another reaction vial containing 0.1 ml
of chloroform. When a volume of 0.1 ml is achieved, cap the reaction vial
immediately and allow to cool. Proceed with the perchlorination as described
in Section 7.3.3.
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11. References
Martin, Robert M., "Construction Details of Isokinetic Source
Sampling Equipment," Environmental Protection Agency, Air Pollution Control
Office Publication No. APTD-0581.
1973 Annual Book of ASTM Standards. Part 23, Designation: D 1179-72,
Thompson, J. F., Ed., "Analysis of Pesticide Residues in Human and
Environmental Samples," Environmental Protection Agency, Research Triangle
Park, N.C., 1974.
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PART B. CAPACITOR- AND TRANSFORMER-FILLING PLANTS
1. Principle and Applicability
1-1 Principle. Gaseous and particulate PCBs are withdrawn isokinet-
Ically from the source. The PCBs are collected on Florisil and determined
by gas chromatography against an Aroclor® standard.
1.2 Applicability. This method is applicable for the determination
of PCB emissions from the room air, room air exhaust and process point ex-
hausts at capacitor- and transformer-filling plants.
2. Rangeand Sensitivity
The range of the analytical method may be expanded considerably
through concentration and/or dilution of the extract. The total method
sensitivity is also highly dependent on the volume of gases sampled. How-
ever, sensitivity of the total method is near 1 ug per test or near 10 ng
per test where the perchlorination assay method is used.
3. Interferences
Throughout all stages of sample handling and analysis, care should
be taken to avoid contact of samples and extracts with synthetic organic ma-
terials other than TF^® (polytetrafluoroethylene). Lubricating and sealing
greases should not be used on the sample exposed portions of the sampling
train.
4. Precision and Accuracy
Sampling with identical and paired sampling trains, the precision
of the method should be 10 to 15% of the PCB concentration measured. Re-
covery efficiencies on source samples spiked with PCB compounds ranged from
85 to 95% of the spike.
5. Apparatus
5.1 Sampling Train. The sampling train, see Figure B-l, consists of a
glass-lined probe, an adsorbent tube containing Florisil, and the appropriate
valving and flow meter controls for isokinetic sampling as described in Part A
of the procedure. The sampling apparatus in Figure B-l is the same as that in
Figure A-l and Section 5.1 of Part A, except that the Smith-Greenburg impingers
and heated probe are not used. If condensation of significant quantities of
moisture prior to the solid adsorbent is expected, Part A of the method should
be used. Since probes and adsorbent tubes are not cleaned up in the field, a
sufficient number must be provided for sampling and allowance for breakage.
C-23
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Probe (to sample from duct) «*—I
Glass-lined Probe
Florisil
Glass Wool
Integrated 1
Flow Meter I
Check Valve
Manometer
Vacuum
Line
Figure B-l. PCB Sampling Train for Capacitor- and
Transformer-Filling Plants
C-24
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5.2 Sample Recovery. Heavy duty aluminum foil must be provided to
cap off the probe prior to shipment.
5*3 Analysis. The equipment required for the analysis is identical to
that specified in Part A except that the equipment necessary for perchlorina-
tion of the PCBs collected to the decachlorobiphenyl form is not required.
(Perchlorination of the sample here is optional and should be employed only
if the GC fingerprint technique of this procedure is not applicable.)
6. Reagents
6.1 Sampling
6.1.1 Florisil—Floridin Company, 30/60 mesh, Grade A. The Flori-
sil is cleaned by overnight Soxhlet extraction with hexane and then drying
overnight at 110°C and is activated by heating to 650°C for 2 hr (not to ex-
ceed 3 hr) in a muffle furnace. After allowing to cool to near 110°C, trans-
fer the clean, active Florisil to a clean, hexane-washed glass jar and seal
with a TFlf®-lined lid. The Florisil should be stored at 110°C until taken
to the field for use. Florisil that has been stored more than 1 month must
be reactivated.
6.1.2 Glass wool—Cleaned by thorough rinsing with hexane, dried
in a 110°C oven, and stored in a hexane-washed glass jar with TF^®-lined
screw cap.
6.2 Analysis
6.2.1 Hexane--Pesticide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.2.2 Acetone—Pesticide quality, Burdick and Jackson "Distilled
in Glass" or equivalent, stored in original containers and used as received.
6.2.3 Sodium sulfate (Na2804)—Anhydrous, granular. Clean by
overnight Soxhlet extraction with hexane, drying in a 110°C oven, and then
beating to 650°C for 2 hr. Store in 110°C oven or in glass jar closed with
TF^®-lined screw cap.
6.2.4 Sulfuric acid (H2SO^>--Concentrated, ACS reagent grade or
equivalent.
6.2.5 Glass wool—Cleaned by thorough rinsing with hexane, dried
in a 110°C oven, and stored in a hexane-rinsed glass jar with TFI^-lined cap.
C-25
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6.2.6 Carborundum boiling stones--Hengar Company No. 133-B or
equivalent, rinsed with hexane.
6.2.7 Standard Aroclor PCB mixtures--Aroclors® 1016, 1221, 1232,
1242, 1248, 1254, 1260, and 1262 may be obtained from the Pesticide Reposi-
tory, EPA/HERL/ETD, Research Triangle Park, North Carolina.
7. Procedure
7-1 Sampling. The sampling shall be conducted by competent personnel
knowledgeable with this test procedure and cognizant of the constraints of
the analytical techniques for PCBs, particularly contamination problems.
The sampling procedure for capacitor and transformer plants is
identical to that described in Part A with the following exceptions: (a)
"impingers and a beatable probe are not required prior to the adsorbent
tube; and (b) the PCB concentrations may be considerably higher for ca-
pacitor and transformer plants, compared to most incinerators, thus the
sampling time can be less than the 2 hr specified in Part A.
The selection of sampling time and rate should be based on the
approximate levels of PCB residues expected in the sample. The sampling
rate should not exceed 14 liters/min and may typically fall in the range
of 5 to 10 liters/min. Sampling times should be more than 20 min but
should not exceed 4 hr.
Because the processes for filling the capacitors and transformers
can vary significantly between plants, isokinetic sampling is required in
the procedure. However, if it can be shown to the satisfaction of the
Administrator that isokinetic sampling is not necessary, then sampling at
a proportional rate is an acceptable alternative. Proportional or constant
flow rate sampling may also be necessary in cases where the standard pitot/
nozzle, assembly physically blocks a significant portion of the stack or
where the flow rate is too low (less than 10 ft/min) for the pitot tube.
7.2 Sample Recovery
7.2.1 Adsorbent tube--Remove the Florisil tube from the collec-
tion system and cap it off with ground glass caps for shipment to the ana-
lytical laboratory.
7.2.2 Probe (where applicable)—Remove the probe from the col-
lection system and cap it off with aluminum foil.
C-26
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7*3 Analysis. The analysis of the FOB samples should be conducted by
chemical personnel experienced in determinations of trace organics utilizing
sophisticated instrumental techniques. All extract transfers should be made
quantitatively by rinsing the apparatus at least three times with hexane and
adding the rinses to the receiving container. A boiling stone should be used
in all evaporative steps to control "bumping."
7.3.1 Extraction
7.3.1.1 Adsorbent tube. Expel the entire contents of the
adsorbent tube directly onto a glass wool plug in the sample holder of a
Soxhlet extractor. Although no extraction thimble is required, a glass
thimble with a coarse-fritted bottom may be used.
Rinse the tube with about 5 ml acetone and then about 15 ml
hexane into the extractor. Assemble the extraction apparatus and extract
the adsorbent with 170 ml hexane for at least 4 hr. The extractor should
cycle 10 to 14 times per hour. After allowing the extraction apparatus to
cool to ambient temperature, transfer the extract into a Kuderna-Danish
evaporator.
Evaporate the extract on a steam bath to about 5 ml and al-
low the evaporator to cool to ambient temperature before disassembly. Trans-
fer the extract to a 50 ml separatory funnel and set the funnel aside.
7.3.1.2 Probe (where applicable). Rinse the probe with hex-
ane into a Kuderna-Danish evaporator. Evaporate the extract to about 5 ml
and allow the evaporator to cool to ambient temperature before disassembly.
Add the concentrated extract to the 50-ml separatory funnel containing the
corresponding Florisil extract.
7.3.2 Extract cleanup—Clean the combined extracts (in 50-ml
separatory funnel) by shaking with 5 ml concentrated sulfuric acid. Allow
the acid layer to separate and drain it off.
Transfer the hexane layer to a Kuderna-Danish evaporator and evap-
orate to about 5 ml. Allow the evaporator to cool to ambient temperature
before disassembly.
The extract should be essentially colorless. If it still shows
significant color, additional cleanup may be required before assaying for
PCBs. In this event, further clean the extract by liquid chromatography on
Florisil according to procedures described in Section 5A of the 1974 issue
of "Manual of Analytical Methods for Analysis of Pesticide Residues in Human
and Environmental Samples." Reduce the Florisil eluant to about 10 ml by
Kuderna-Danish evaporation techniques described above.
C-27
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Transfer the cleaned extract to a 25-ml volumetric flask and dilute
to volume with hexane for gas chromatographic analysis.
7.3.3 PCB determination—Assay the cleaned extracts by gas chromato-
graphic comparison with standard solutions of a similar commercial PCB mixture
(A column temperature between 165 and 200°C at a flow rate of 30 ml/min may be
appropriate. Aroclot®standard solutions at concentrations near 10 ng/ul should
be appropriate for calibration of the gas chromatograph.) If PCB mixtures were
being used at the sampling site, a standard solution of that mixture, e.g.,
Aroclor® 1016, will likely be appropriate. Quantitation should be based on the
summed areas of at least five major peaks coincident in the chromatograms of
the sample extracts and standards. The range and sensitivity of the method
may be extended somewhat by diluting concentrated extracts with hexane or
concentrating dilute extracts by evaporation under a gentle stream of dry
nitrogen. If the sample chromatograms do not closely resemble a particular
PCB standard, e.g., in the case of emissions from more than one Aroclor®
product, refer to Section 10.1 concerning Special Cases. Correct the PCB
assays for PCBs determined in the blank train.
8. Calibration
Maintain a laboratory log of all calibrations.
8.1 Sampling Train
8.1.1 Probe nozzle--Using a micrometer, measure the inside diameter
of the nozzle to the nearest 0.025 mm (0.001 in.). Make three separate mea-
surements using different diameters each time and obtain the average of the
measurements. The difference between the high and low numbers shall not ex-
ceed 0.1 mm (0.004 in.).
When nozzles become nicked, dented, or corroded, they shall be re-
shaped, sharpened, and recalibrated before use.
Each nozzle shall be permanently and uniquely identified.
8.1.2 Pitot tube—The pitot tube shall be calibrated according
to the procedure outlined in Method 2.
8.1.3 Dry gas meter and orifice meter—Both meters shall be cali-
brated according to the procedure outlined in APTD-0576. When diaphragm
pumps with bypass valves are used, check for proper metering system design
by calibrating the dry gas meter at an additional flow rate of 0.0057 m3/min
(0.2 cfm) with the bypass valve fully opened and then with it fully closed.
If there is more than + 2% difference in flow rates when compared to the
fully closed position of the bypass valve, the system is not designed properly
'ind must be corrected.
C-28
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8.1.4 Temperature gauges—Calibrate dial and liquid filled bulb
thermometers against mercury-in-glass thermometers. Thermocouples need not
be calibrated. For other devices, check with the Administrator.
8.2 Analytical Apparatus
8.2.1 Gas chromatograph--Prepare a working curve from at least
five standard injections of different volumes of the Aroclor® standard in
hexane solution.
9. Calculations
Carry out calculations, retaining at least one extra decimal fig-
ure beyond that of the acquired data. Round off figures after final calcu-
lations.
9.1 Nomenclature
Gs " Total weight of Aroclor® in sample, ug.
Cg = Concentration of Aroclor® in stack gas, ug/m3, corrected to
standard conditions of 20°C, 760 mm Hg (68°F, 29.92 in. Hg).
An - Cross-sectional area of nozzle, m* (£t2).
I = Percent of isokinetic sampling.
Pfcar = Barometric pressure at the sampling site, mm Hg (in. Hg).
Pg = Absolute stack gas pressure, mm Hg (in. Hg).
P8td •= Standard absolute pressure, 760 mm Hg (29.92 in Hg).
R = Ideal gas constant, 0.06236 mm Hg-m3/°K-g-mole (21.83 in.
Hg-ft3/°R-lb-mole).
Tm = Absolute average dry gas meter temperature °K (°R).
T8 » Absolute average stack gas temperature °K (°R).
Tstd e Standard absolute temperature, 293°K (528eR).
VQ * Volume of gas sample as measured by dry gas meter, dcm (dcf).
C-29
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* Volume of gas sample measured by the dry gas meter corrected to
standard conditions, dscm (dscf ) .
V8 = Stack gas velocity, calculated by Method 2, Equation 2 to 7, m/sec
(ft/sec).
AH = Average pressure differential across. the orifice meter, mm H2<)
(in. H2<>).
9 «= Total sampling time, min.
13.6 • Specific gravity of mercury.
60 m Sec /min.
100 - Conversion to percent.
9.2 Average dry gas meter temperature and average orifice pressure
drop.
9.3 Dry Gas Volume. Correct the sample volume measured by the dry
gas meter to standard conditions [20°C, 760 mm Hg (68°F, 29.92 in. Hg)]
by using Equation B-l.
vn(8td)
Tstd
im
AH
?bar + 13.6
*std
AH
KVm Pbar + 13.6
T,
m
Equation B-l
where K = 0.3855 °K/mm Hg for metric units
= 17.65 °R/in. Hg for English units
9.4 Concentration
9.4.1 Concentration of Aroclor® in stack gas. Determine the
concentration of Aroclor® in the stack gas according to Equation B-2.
C8 = ___2 - Equation B-2
vm(std)
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10. Special Cases
10.1 Quantitation of PCS Residues Not Similar to a Commercial Mixture.
In cases where the composition of the PCB residue does not closely resemble
an available commercial PCB mixture, i.e., from comparison of EC-GC chromato-
grams, direct quantitation against available standard mixtures may be diffi-
cult and inaccurate. These extracts should be split, perchlorinated, and
total PCBs quantitated by procedures described in Part A, Sections 7.3.2,
7.3.3, and 7.3.4, and the total PCB residue of the sample calculated from
Equation A-4.
10.2 PCB. Verification. It is recommended that an unperchlorinated
aliquot from at least one sample be subjected to GC/MS examination to ver-
ify that PCB isomers are present.
After determining what PCB isomers are possibly present by the
quantitation procedures in Section 7.3.3, the sample is examined by GC/MS
using multiple ion selection techniques for ions characteristic of the
molecular clusters of the PCBs possibly present.
11. Reference
Martin, Robert M., "Construction Details of Isokinetic Source
Sampling Equipment," Environmental Protection Agency, Air Pollution Control
Office of Publication No. APTD-0581.
1973AnnualBook of ASTM Standards, Part 23, Designation: D 1179-72
Thompson, J. F., Ed., "Analysis of Pesticide Residues in Human and
Environmental Samples," Environmental Protection Agency, Research Triangle
Park, N.C., 1974.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-79-047
2.
3, RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Measurement of PCB Emissions from Combustion
Sources
6. REPORT DATE
February 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOH(S)
P.L.Levins, C.E.Rechsteiner, and J.L.Stauffer
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Arthur D. Little, Inc.
Acorn Park
Cambridge, Massachusetts 02140
10. PROGRAM ELEMENT NO.
INE624
11. CONTRACT/GRANT NO.
68-02-2150, T.D. 10102
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final: 12/76 - 12/78
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES
2557.
^ 3 JohllSOn , MD-62, 919/541-
16. ABSTRACT
The report describes a gas chromatographic/mass spectrometric (GC/MS) procedure
that overcomes problems encountered when using GC procedures (previously used
to determine polychlorinated biphenyls (PCBs) in solids and water) on emissions
from combustion sources. The GC/MS procedure, which relies on selected mass
scanning in restricted regions of the chromatograms, was developed because in
the combustion process the distribution pattern of the individual PCBs changes,
rendering invalid the pattern matching approach used with the gas chromatographic/
electron capture detection (GC/ECD) method.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
COS AT I Field/Group
Pollution
Chlorine Aromatic Compounds
Biphenyl Mass Spectroscopy
Combustion
Measurement
Gas Chromatography
Pollution Control
Stationary Sources
Polychlorinated Bi-
phenyls
13B
07C
21B
14B
07D
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
88
20. SECURITY CLASS (This pagel
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
C-32
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