United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 80-BYC-4
March 1981
Air
Benzene
Coke Oven By-Product
Plants
Emission Test Report
Republic Steel
Corporation
Gadsden, Alabama
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SET 1957 03 1280
BENZENE SAMPLING PROGRAM
AT COKE BY-PRODUCT RECOVERY PLANTS:
REPUBLIC STEEL CORPORATION
GADSDEN, ALABAMA
EPA Contract 68-02-2813
Work Assignment 48
ESED Project No. 74/4j
Prepared For:
Mr. Daniel Bivins
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emission Measurement Branch, ESED, MD-13
Research Triangle Park, North Carolina 27711
March 1981
SCOTT ENVIRONMENTAL SERVICES
A Division Of
SCOTT ENVIRONMENTAL TECHNOLOGY, INC.
Plumsteadville, Pennsylvania 18949
Scott Environmental Technology Inc.
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SET 1957 03 1280
TABLE OF CONTENTS Page No.
1.0 INTRODUCTION 1-1
2.0 SUMMARY OF RESULTS 2-1
3.0 RESULTS AND DISCUSSION 3-1
4.0 PROCESS DESCRIPTION 4-1
5.0 FIELD SAMPLING AND ANALYSIS METHODOLOGY 5-1
5.1 TRACER TESTING 5-1
5.2 SAMPLE HANDLING ' 5-1
5.3 FIELD ANALYSIS - 5-2
6.0 FIELD SAMPLING PROCEDURES 6-1
6.1 LIGHT OIL INTERCEPTING SUMP 6-1
7.0 LABORATORY SAMPLE ANALYSIS 7-1
7.1 SAMPLE PREPARATION 7-1
7.2 PURGE AND TRAP PROCEDURE FOR EXTRACTION 7-2
OF BENZENE FROM LIQUID PHASE TO
GASEOUS PHASE
7.3 GAS CHROMATOGRAPH 7-4
8.0 QUALITY CONTROL AND QUALITY ASSURANCE 8-1
8.1 FIELD ANALYSIS PROCEDURES 8-1
8.2 PROCEDURES FOR ANALYSIS OF PROCESS 8-2
LIQUIDS
APPENDICES
APPENDIX A - SAMPLE CALCULATIONS
APPENDIX B - FIELD DATA SHEETS
APPENDIX C - LABORATORY DATA SHEETS
APPENDIX D - TRACER GAS METHOD DEVELOPMENT
APPENDIX E - PROJECT PARTICIPANTS
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SET 1957 03 1280 Page 1-1
1.0 INTRODUCTION
Scott Environmental Services, a division of Scott Environmental
Technology, Inc. conducted a testing program at Republic Steel Corporation
in Gadsden, Alabama to determine benzene emissions from one source in the
coke by-product recovery plant. The work was performed for the United
States Environmental Protection Agency, Emissions Measurement Branch,
under Contract No. 68-02-2813, Work Assignment 48. Republic Steel was
one of seven plants visited to collect data for a possible National
Emission Standard for Hazardous Air Pollutants for benzene.
Sampling was conducted at Republic Steel on October 16 and 17,
1980. Air and liquid samples for benzene analysis were collected from the
light oil intercepting sump.
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SET 1957 03 1280
Page 2-1
2.0 SUMMARY OF RESULTS
LIGHT OIL INTERCEPTING SUMP - TRACER DATA SUMMARY
Benzene Emission Rate
Test 1
Test 2
Test 3
Run 1
Run 2
Run 1
Run 2
Run 1
Run 2
Ib/hr
4.27
4.50
5.41
5.21
6.29
5.13
2.46
2.37
2.86
2.33
Avg.
5.14
2.38
LIQUID SAMPLE DATA
Sample Location
West Side - Inlet
Middle
Outlet
East Side - Inlet
Middle
Outlet
Date
10/16/80
10/16/80
10/16/80
10/16/80
10/16/80
10/16/80
•
Time
11:25
11:27
11:30
11:35
11:37
11:40
Sample
Temp.
(°F)
87
82
114
146
139
156
Benzene
Concentration
(ppm by weight)
25,800
27,900
18.0
97.1
86.7
1.0
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SET 1957 03 1280 Page 3rl
3.0 RESULTS AND DISCUSSION
The light oil intercepting sump is comprised of two separate
halves, called east and west for identification purposes. Figure 3-1 shows
the sump configuration-and location of samplers.
During sampling, the tracer gas manifold was located along the
wall separating the two sides of the sump; consequently the emission rate
for the entire sump was measured. The average benzene emission rate
from the sump was 5.14 Ib/hr.
The average benzene concentration in the organic liquid on the
surface of the sumps was 27,000 ppm for the west side and 92 ppm for the
east side. The concentrations in the aqueous phase which was present at
'•'. -the outlets were 18 and 1 ppm for the respective sides. The outlet samples
were dipped from th^-wells at the south side of the sump, which act as
skimmers or weirs by drawing the liquid at the bottom of the sump under
the wall into the outlet well.
The average temperature of the liquid in the east sump was 147°F
while the average temperature of the wtest sump was 94°F. In both sumps
higher temperatures were measured at the inlets and outlets than in the
middle. .
The large variations in benzene concentration and temperature
found across the surface of the sump suggest non-uniformity in benzene
emission rates. The benzene concentration in the surface layer of the
west side was 300 times that in the east side. Thus, it would be expected
that most of the benzene emissions would come from the west side even
though its temperature was 60°F lower than the east side. Both sumps were
bottom filled, but there was some turbulence at the inlets. The turbulence
Scott Environmental Techndogy Inc
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Page 3-2.
OUTLETS
23'
WIND
DIRECT! 01
.UPWIND
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ys \ :
;'
„/
1
TRACER
GAS
MANIFOLD -
EAST
S/DE
« 5'
/
rv.
k
f
?
LAST)
1
•«
->
\
w
•s
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c
r
'EST
IDE
^ii <
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XX
INLETS
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SAMPL
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Environmental
FIGURE 3-1 LIGHT OIL INTERCEPTING SUMP
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SET 1957 03 1280
Page 3-3
probably caused the highest emissions to occur at the inlet end of the
west sump. This is believed to be responsible for the higher emission
rates indicated by Sampler 3 in the first three runs (See Table 3-1).
During these three runs the air flow was such that Sampler 3 was downwind
of the inlet area. Overall, the run to run and sampler to sampler vari-
ations are relatively small, and there is every indication that the
calculated benzene rates accurately depict the sump's emissions to the
atmosphere.
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SET 1957 03 1280
Page 3-4
TABLE 3-1
TRACER DATA
Republic Steel, Gadsden, Alabama
Cone, of Cone, of
Sample Benzene Isobutane
Loc. (ppm) (ppm)
10/16/80, a.m.
Test //I, Run //I
Isobutane release
1 4.44
2 2.19
3 1.72
Upwind 0.13
10/16/80, a.m.
Test #1, Run #2
Isobutane release
1 2.62
2 2.53
3 3.50
Upwind 0.14
10/16/80, p.m.
Test #2, Run #1
Isobutane release
1 3.43
2 3.20
3 3.48
Upwind N.D.
10/16/80, p.m.
Test #2, Run #2
Isobutane release
1 4.58
2 5.25
3 3.43
Upwind 0.44
Q£) Scott Environmental
rate: 1.16 Ib/hr
1.71
0.96
0.52
N.D.
rate: 1.16 Ib/hr
1.18
1.10
0.85
N.D.
rate: 1.15 Ib/hr
1.20
1.30
0.68
N.D.
rate: 1.15 Ib/hr
1.53
1.40
1.03
N.D;.
Technology Inc.
Mass to Mass
Ratio
3.49
3.07
4.49
3.00
3.07
5.56
3.85
3.31
6.94
4.04
5.05
4.50
Avg.
Avg.
Avg.
Avg.
Benzene Emission Rate
(Ib/hr) (kg/hr)
4.05
3.56
5.21
4.27
3.48
3.56
6.45
4.50
4.47
3.81
7.98
5.41
4.65
5.81
5.18
5.21
1.84
1.62
2.37
1.94
1.58
1.62
2.93
2.05
2.03
1.73
3.63
2.46
2.11
2.64
2.35
2.37
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SET 1957 03 1280
Page 3-5
Table 3-1
(Continued)
Cone, of
Benzene
(ppm)
10/17/80, a.m.
Test #3, Run #1
Isobutane release rate:
1
2
3
Upwind
1.86
1.09
4.53
0.61
10/17/80, a.m.
Test #3, Run #2
Isobutane release rate:
Cone, of
Isobutane
1
2
3
Upwind
1.33
2.68
4.74
0.61
1.15 Ib/hr
0.54
0.25
1.01
N.D.
Mass to Mass
Ratio ifr/ic,
1.14 Ib/hr
0.39
0.91
1.47
N.D.
4.64
5.96
5,. 8 2
5.20
3.97
4.34
Avg.
Avg.
Benzene Emission Rate
(Ib/hr)
5.34
6.85
6.69
6.29
5.
4.
4.
93
53
95
5.13
(kg/hr)
2.43
3.12
3.04
2.86
69
06
45
2.60
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SET 1957 03 1280 Page 4-1
4.0 PROCESS DESCRIPTION
The light oil intercepting sump is used to collect waste waters
from the light oil refining operations. Gravity separates the oil-water
waste for reclamation of the light oil. The light oil intercepting sump
at Republic Steel in Gadsden, Alabama was open to the atmosphere and was
27 feet long, 11 feet wide and approximately 4 feet deep. The liquid
level was approximately three feet below ground level. The sump was
divided in half along its length by a wall and was actually two separate
sumps, each of which had a separate inlet located on the north side of
the sump and an outlet on the south side.
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SET 1957 03 1280 Page 5-1
5.0 FIELD SAMPLING AND ANALYSIS METHODOLOGY
5.1 TRACER GAS METHOD FOR DETERMINATION OF FUGITIVE BENZENE EMISSIONS
The tracer gas method is a practical procedure for quantifying
mass emissions of volatile organics from sources which are essentially
open to the atmosphere without disturbing flow, dispersion patterns or
the source operation. This method utilizes the release of a tracer gas
directly over the source of interest; the tracer gas will then follow the
same dispersion patterns as the emissions from the source. The mass of
tracer released over the sampling period is known and the mass to mass
ratio of benzene to the tracer gas in the sample is determined by gas
chromatography. The emission rate of the benzene can be calculated with
this information.
This method is based on the principle that the chosen tracer gas
will model the dispersion of benzene from the source.. The tracer gas
chosen for this project was isobutane because it was not present in the
sources to be tested and it could readily be separated from other source
trace components by the same column used for benzene. In addition, iso-
butane is a non-toxic gas that can readily be dispensed from a pressurized
cylinder at a uniform measured rate.
When this method was used triplicate tests were performed. Each
test consisted of two 1/2 hour runs. For each run clean and backgrounded
ten-liter Tedlar* bags were used. Integrated samples were collected using
Emission Measurements, Inc» Air Quality Sampler II* systems. The AQS II
samplers are self-contained units capable of collecting one or more inte-
grated samples at a preset rate. For tracer tests the sampling rate used
was ten liters per hour.
5.2 SAMPLE HANDLING
After being collected the gas samples were immediately transported
to the gas chromatograph and analyzed. The elapsed time between sample
collection and analysis never exceeded one hour. To verify that there was
no sample degradation in samples of this type some of the samples were
retained for 24 hours and reanalyzed. The loss of benzene and isobutane
observed was typically less than 5%.
*Mention of trade names or specific products does not constitute endorsement
by the U.S. Environmental Protection Agency.
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SET 1957 03 1280 Page 5-2
5.3 FIELD ANALYSIS
All gas samples collected were analyzed using a Shimadzu GC Mini 1
gas chromatograph equipped with dual flame inoization detectors, dual
electrometers, heated sample loop and a backflush system. Figure 5-1 shows
a schematic of the backflush apparatus. The backflush system is composed
of ten port sequence reversal valve and two columns, a scrubber column for
retaining high molecular weight compounds and an analytical column. When
the system is in the inject mode the scrubber column and the analytical
column are connected in series allowing sample components to move from the
precolumn to the analytical column. In the backflush mode the columns are
disconnected from each other and become two separate systems each with its
own carrier gas source. This arrangement allows the separation and
measurement of low molecular weight compounds while the scrubber column
is being backflushed of heavier sample components. Backflush times for
different mixtures of sample components must be predetermined to insure that
the compound(s) of interest are transferred to the analytical column before
backflushing is started.
Samples for chromatographic analysis were drawn into a 20 cc glass
syringe then introduced to the sample loop inlet. The samples once in the
sample loop were allowed to come to atmospheric pressure by waiting 15
seconds prior to the injection. When only benzene was of interest the
following chromatographic conditions were maintained:
Column Temperature (isothermal) - 100°C
Injector and Detector Temperature - 200°C
5 ml Sample Loop, Temperature - 50°C
Carrier Gas Flow Rate - 32 cc/min
Hydrogen Flow Rate — 40 cc/min.
Air Flow Rate - 240 cc/min.
Analysis Time - 5 min.
Detector - Flame lonization
Scott Environmental Technology Inc.
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(I
XI
o
C!
Ol
I
CARRIER GAS A
A
fl
B •>
CARRIER GAS B
D
PREP, COLUMN
ANALYTICAL COLUMN
DETECTOR
SAMPLE INJECTION
INJECT
A, D, E OPEN
B, C CLOSED
BACKFLUSH
A, E CLOSED
B, C, D OPEN
GC COLUMN CONFIGURATION WITH BACKFLUSH
ui
I
u>
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SET 1957 03 1280 page 5-4
The columns used for field analysis were:
A - Scrubber Column
10% FFAP on Supelcoport 80/100
1/8" x 1 m Stainless Steel
B - Analytical column
20% SP-2100, 0.1% Carbowax 1500
100/120 Supelcoport
1/8" x 10' Stainless Steel
When samples from tracer tests were analyzed the chromatographic
conditions were changed to provide adequate separation of the isobutane
tracer from the other light components of the sample. The temperature
program used for this analysis was:
1) Start at room temperature with external cooling fan
on and oven door open.
2) Inject (§0.0 min.
3) Turn external cooling fan off (§1.0 min.
4) Backflush (§1.8 min.
5) Isobutane elutes @ 2.3 min.
6) Close oven door @ 3.0 min. with oven temperature
set at 100°C.
7) Benzene elutes @ 7.0 min.
8) After the elution of benzene, open the oven door and
turn on the cooling fan. The next injection can be
made after 2 minutes of cooling.
9) When the tracer gas is used analysis time will be
approximately 10 minutes.
*
The columns and flow rates were the same as for- isothermal.
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SET 1957 03 1280 Page 6-1
6.0 FIELD SAMPLING PROCEDURES
6.1 LIGHT OIL INTERCEPTING SUMP
The sump was a fugitive emission source which was sampled using
the tracer gas method. When using this method, best results are obtained
by releasing the tracer gas at the liquid surface level along the central
axis of the source perpendicular to the wind direction. This was accom-
plished for this source by placing the dispersion bar on the wall which
separated the east and west sides of the sump, as depicted in Figure 3-1.
The wall ran north and south and was approximately 4-6 inches above the
liquid level of the sump. The tracer gas source was connected to the
center of the 27 foot long dispersion bar which was comprised of six
4 1/2 foot sections joined by Swagelok connectors. On each side of the
dispersion bar the holes in the bar were 19 inches apart and were of
increasing size outward from the tracer source. The first section con-
tained holes -that were 0.166 inches in diameter, the second section
contained holes 0.169 inches in diameter and the third section had holes
that were 0.173 inches in diameter. Visual inspection of the dispersion
bar at release rates typically used for testing showed that approximately
the same volume of gas was exiting the holes in various sections of the bar.
Three samplers were positioned 7 feet from the sump on its west
side and the presence of isobutane and benzene at the sampler locations
was verified by analyzing grab samples. The upwind sampler was positioned
approximately 20 feet from the sump's northeast corner.
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SET 1957 03 1280 Page 7"1 '
7.0 LABORATORY SAMPLE ANALYSIS
»
Two types of liquid samples were collected: process liquids, and
sample line and water trap catches and washes. All liquid samples were
stored in amber glass bottles and returned to Scott's Plumsteadville laboratory
for analysis.
7.1 SAMPLE PREPARATION
Depending upon the complexity of the sample, one of the following
sample preparation procedures was followed prior to the "purge and trap"
procedure and analysis.
Samples Containing Immiscible Liquid Phases
Using a clinical centrifuge (International Equipment Company,
Massachusetts) immiscible liquid phases were separated and each phase was
analyzed separately for benzene.
Samples Containing Solid and Immiscible Liquid Phases
Samples containing solids of higher density than the liquid phase
were separated by centrifuge or by sample decantation of the liquid. The
different phases in the liquid fraction were then further separated by
centrifuging. Solid and liquid phases were analyzed separately.
Samples Containing Finely Crystalline Solid Suspension
In analyzing these samples the stoppered sample jars were shaken
for at least half an hour for homogenizing the solution. The uniform >
distribution of suspended fine crystalline solid particles was tested by
determining the percentage of dry solid in several aliquots of the homoge-
nized mixture. A weighed amount of the mixture was analyzed for benzene.
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SET 1957 03 1280 PaSe 7~2
Sampling System Washings
All washings were clear solutions having only one liquid phase.
The total weight of the liquid phase was determined using a balance correct
to ±0.1 g. The total weight of each washing vss more than 25 grams, so an
error of 0.1 g in weighing the mass will contribute an error of only 0.4%
to the final analytical data. A weighed aliquot of the washing was analyzed
for benzene by following the "purge and trap" and analysis procedures out-
lined in the following sections, and using this analysis data the weight
of benzene present in the total mass of washing was calculated.
7.2 PURGE AND TRAP PROCEDURE FOR EXTRACTION OF BENZENE FROM LIQUID PHASE
TO GASEOUS PHASE
An accurately weighed quantity of the sample to be analyzed was
diluted with 20-25 ml of propylene carbonate in a specially designed glass
purging apparatus which was kept immersed in a thermostatted water bath
maintained at 78°C. Benzene free nitrogen gas was bubbled through the
propylene carbonate solution in the purging apparatus at the rate of
0.2 - 0.3 liters/minute, and collected in leak free Tedlar bags. Under
these experimental conditions, 1 1/2 - 2 hours were sufficient to purge.
off all the benzene from the liquid phase to the gaseous phase.' The total
volume of nitrogen gas used to purge the sample was accurately measured
by a calibrated dry gas meter. A diagram of the purge and trap set-up is
shown in Figure 7-s-l.
Propylene carbonate was found to be an ideal diluting solvent
for the extraction of benzene from all types of liquid samples containing
viscous tar, pitch, light and heavy oil and insoluble particulates. It
was chosen for its high boiling point, low density, and good solvating
capacity.
Scott Environmental Technology Inc.
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NlTROGEM
CYLINDER.
FIGURE 7-1 PURGE AND TRAP METHOD EQUIPMENT SET-UP
00
n>
u>
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SET'1957" 03"-1280;-- Page 7-4
7.3 GAS CHROMATOGRAPH
A Perkin-Elraer 900 gas chromatograph was used for the analysis
of the purge bags. A 10 ft. by 1/8 inch stainless steel column packed with
20% SP-2100/0.1% Carbowax 1500 on 80/120 mesh Supelcoport was used for the
analysis. This column gave complete resolution of the benzene peak from
other components present in the purge bags. The 'peak height* method was
utilized to calculate the concentration of benzene in the purge bags
analyzed. The Perkin-Elmer 900 used for analysis was not equipped with ,
a backflushing unit. Gas chromatograph conditions were as follows:
GC column temperature: 70°C isothermal
Detector temperature: 190°C
5 ml loop at a temperature of 120°C
Carrier gas flow rate: 30 cc/min He
Hydrogen flow rate: 45 cc/min
Oxygen flow rate: 400 cc/min '.
Detector: Flame lonization Detector (FID)
In addition to benzene, the purge bags contained other volatile
hydrocarbons present in the liquid samples such as toluene and naphthalene.
Because this chromatograph was not equipped with a backflush, it was
necessary to elute all heavy organics from the column by heating the column
to 150°C after every two injections for one hour with the carrier gas on.
After cooling the column to 70°C the absence of any organic in the column
which might overlap the benzene peak in the next analysis was checked. When
the column was found to be satisfactorily clean, the next analysis was
continued under the conditions previously described.
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SET-1957 03 128&- Page 8-1
8.0 QUALITY CONTROL AND QUALITY ASSURANCE
The following sections will address quality control and quality
assurance procedures for the: field analysis of benzene in air samples and
the laboratory analysis of process liquids and BaP samples.
8.1 FIELD ANALYSIS PROCEDURES
All samples were analyzed in duplicate and as a rule peak heights
were reproduced to within 5%. For some very high concentration samples
(percent range) it was necessary to make, dilutions for analysis. When this
was done a fresh dilution was prepared for 'each injection and peak heights
were reproduced to within 10%. To verify that the system was retaining no
benzene, frequent injections of the standard and nitrogen were made. In all
cases the result was satisfactory.
The Tedlar bags that were reused for sampling were flushed three
times with nitrogen and allowed to sit overnight after being filled to
approximately three quarters of their capacity. They were analyzed for
benzene content the following day. The background concentrations of the
bags were recorded and varied from 0 to 10 ppm benzene. Care was taken to
use sample bags whose background concentration was very low compared to the
expected concentration of the source.
The accuracy and linearity of the gas chromatographic techniques
used in this program, were tested through the use of EPA Audit Samples. Two
standards, a 122.5 ppm and 6.11 ppm benzene were used to analyze the audit
cylinders.
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SET "195 7 0^1280 Page 8-2
8.2 PROCEDURES FOR ANALYSIS OF PROCESS LIQUIDS
Scott's benzene standards, checked against EPA Audit Standards,
were used as reference standards throughout this program. The accuracy and
linearity of the gas chromatographic technique for benzene analysis was
tested through the use of EPA Audit Standards which were available to Scott.
Gas chromatographic analysis of the samples and standard were performed
under identical conditions to assure the accuracy of the analytical data
generated.
Each batch of propylene carbonate which was used as the diluting
solvent in the purge and trap technique was analyzed for benzene content by
subjecting 25 ml of propylene carbonate to the purge and trap procedure
followed by gas chromatographic analysis of the trapped gas under identical
conditions as described in Section 5.2. All batches of analytical grade
propylene carbonate were found to be free from benzene.
Every day before the analysis of samples the purging apparatus and
trapping bags were tested for absence of benzene. Whenever the whole system
was found to be free from benzene to the lowest detectab-le limit of the
instrument, the samples were analyzed using the purging apparatus and the
trapping gas sampling bags.
Generally an accurately weighed mass of each sample was subjected
to purge and trap procedure only once and the trapped gas sample was repeat-
edly analyzed by GC until the analytical data of consecutive GC analyses varied
by ±0.5% or less.
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' SHE-195-7 03 1Z8G- Page 8~3
For randomly selected samples, the whole analytical procedure was
repeated with a different weighed mass of the source sample to check the
validity and accuracy of the analytical methodology; The analytical data
for different runs were found not to vary by more than 5%.
By purging the sample with nitrogen under the experimental con-
ditions as utilized by Scott, the recovery of benzene from the sample was
quantitative and this has been verified by analyzing a standard benzene
solution in propylene carbonate containing tar and pitch.
Scott Environmental Technology Inc.
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