United States
Environmental Protection
Agency
Environmental Monitoring and
Support Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S4-85/069 Jan. 1986
Project Summary
Determination of Chlorinated
Hydrocarbons in Industrial
and Municipal Wastewaters
J. R. Florence, J. R. Hall, M. Khare, S. M. Maggio,
J. C. Mitchell, R. A. Solomon, J. R. SoloRio,
D. L. Strother, and M. N. Wass
The objective of the full report is to
present the data and the research
carried out to develop an analytical test
procedure for specific organic toxic
substances in effluent wastewaters.
The test procedure is for the analysis of
nine of the 114 priority or toxic pollu-
tants identified by the EPA as Category
3—Chlorinated Hydrocarbons.
The procedure consists of several
steps, including extraction, concentra-
tion, clean up, and quantification by gas
chromatography with electron-capture
and flame-ionization detection.
The full report describes the research
performed leading to the selection of
the procedures and includes data and
information from a literature search,
sample preservation procedures, elu-
tion of the compounds on various gas
chromatographic columns, several sol-
vent extraction efficiencies versus pH,
stability of compounds in water-soluble
solvents, sample extract dean up pro-
cedures, and application of the proce-
dures on effluent wastewaters.
This Project Summary was devel-
oped by EPA's Environmental Monitor-
ing and Support Laboratory, Cincinnati,
OH, to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
The Federal Water Pollution Control
Act Amendments of 1972 (PL92-500)
and the Amendments of 1977 (PL95-
217) required that the Administrator of
the U.S. Environmental Protection
Agency promulgate guidelines estab-
lishing test procdures for the analysis of
the priority pollutants, which were sep-
arated into 12 categories. The full report
covers the research activity required in
the method development for Category
3—Chlorinated Hydrocarbons.
The nine compounds in Category 3—
Chlorinated Hydrocarbons are hex-
achloroethane, hexachlorobutadiene,
hexachlorocyclopentadiene, 1,2-
dichlorobenzene, 1,3-dichlorobenzene,
1,4-dichlorb benzene, 1,2,4-
trichlorobenzene, hexachlorobenzene,
and 2-chloronapthalene.
The program included a literature
search from 1960 through 1978, sample
preservation studies, evaluation of sol-
vents for liquid-liquid extraction, stabil-
ity studies of the compounds in water-
miscible solvents, and evaluation of
sample and extract clean up proce-
dures.
The gas chromatographic characteris-
tics data of the category compounds are
presented and include information on
retention times with various gas chro-
matography columns at different tem-
peratures, responses to both electron-
capture and flame-ionization detectors,
linearity curves and chemical data for all
compounds, and minimum detection
limits.
Based on the information gathered in
the research program, a test method
was proposed for Category 3. The pro-
posed method was then used to de-
velop data on overall compound recov-
eries in spiked distilled water and
wastewater effluent samples.
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The developed test procedure was
originally published in the December 3,
1979 issue of the Federal Register as
EPA Method 612 and subsequently was
included as one of the EPA Test Meth-
ods of Organic Chemical Analysis of
Municipal and Industrial Wastewater.1'2
Conclusions and
Recommendations
The results of the preservation study
experiments indicate that the samples
are best preserved when the pH is ad-
justed to 2, dechlorinated with sodium
thiosulfate, exposed to a minimum of
UV light, and stored and shipped at a
temperature of 4°C. These procedures
should be implemented as soon as pos-
sible after the samples have been col-
lected. Even under these conditions,
however, storage for seven days at low
levels (<10mg/L) led to losses ranging
from 22 to 76%, whereas at higher con-
centrations of the chlorinated rr'drocar-
bons (200 to 300mg/L), losses were only
2 to 18%.
The extraction of one-liter water sam-
ples, with three 60-ml portions
dichloromethane per liter, after adjust-
ment to pH 2 with 1 N H2S04, was found
to give the best overall extraction effi-
ciencies. The second highest extraction
efficiencies were obtained at pH 6.0 to
8.0. This range is recommended for con-
venience. However, data on spiked dis-
tilled water show that the extraction effi-
ciencies at the mg/L level are 10 to 20%
lower than at concentration levels one
to two orders of magnitude higher. The
dichlormethane was concentrated in a
Kuderna-Danish evaporator with sol-
vent exchange to hexane.
When the sample extracts require no
further clean up, they are best analyzed
by electron-capture gas chromatogra-
phy. The evaluation of several chro-
matographic columns led to the selec-
tion of Gas - Chrom Q coated with 1.5%
OV-1 and 1.5% OV-225 operated under
two isothermal conditions, 75°C and
165°C. All nine compounds are resolved
by this column. The minimum resolu-
tion of 0.7 occurs between the meta-
and para-dichlorobenzene isomers.
This resolution between all the
dichlorobenzenes and hexachloro-
ethane, however, is variable with con-
centration; that is, high mg/L levels of
hexachloroethane may make detection
difficult at the mg/L level of para- and
ortho-dichlorobenzene.
The original gas chromatographic
packing was prepared by mixing equal
volumes of Gas - Chrom Q coated with
1.5% OV-1 and 1.5% OV-225. Problems
were encountered in preparing repro-
ducible lots of this packing. It was
subsequently discovered that a blended
gas chromatographic column packing
of 1.5% OV-1 and 2.25% OV-225 on
Supelcoport gave identical results and
performance to the original mixed
phase packing and yet was reproducible
from lot to lot. Therefore, the blended
packing has been recommended for the
analyses of the chlorinated hydrocar-
bons.
Table 1 summarizes the gas chro-
matographic operating conditions, re-
tention times, and Method Detection
Limits (MDL) obtained under these con-
ditions. The separation of the nine chlo-
rinated hydrocarbons achieved by the
blended phase column is shown in Fig-
ures 1 and 2.
The Category 3 compounds' re-
sponses were found to be linear over
the range of 1 to 10,000 mg/L.
A rapid Florisil® column clean up pro-
cedure was developed for complex ex-
tracts. This procedure has the advan-
tage of keeping all the Category 3
compounds in one eluant, yet providing
separation for nine polar halogenated
extracted components that may inter-
fere with the analysis. The clean up pro-
cedure eliminates many late eluting
halogenated compounds that slow
down the analysis turnaround time. The
procedures developed during the study
(Figure 3) were successfully applied to
three treated industrial effluent samples
and a municipal primary effluent sam-
ple. Two of the industrial effluents
showed no Category 3 compounds. The
municipal wastewater showed five of
the componds at less than 20 mg/L and
the remaining industrial wastewater
showed seven of the nine compounds
at 0.4 to 120 mg/L.
The accuracy of the method based on
spiked solutions of distilled-deionized
water expressed as percent of recovery
varied from 65% for hexachlorobenzene
to 90% for 2-chlor-napthalene at the low
mg/L level. The method precision,
based on spiking the worst sample eval-
uated, had a single operator coefficient
of variation that ranged from 15% for
p-dichlorobenzene to 52% for hex-
achlorobenzene.
Column: 1.5% OV-1+ 1.5% OV-225
on Gas Chrom Q
Temperature: 75°C
Detector: Electron Capture
A. 1,3-Dichlorobenzene
B. 1,4-Dichlorobenzene
C. Hexachloroethane
D. 1,2 -Dichlorobenzene
E. Hexachlorobutadiene
F. 1,2,4-Trichlorobenzene
0 5 JO 15 20
Retention Time-Minutes
Figure 1. Gas chromatogram of chlori-
nated hydrocarbons.
Table 1. Chromatographic Conditions and Method Detection Limits
Parameter
1 ,3-Dichlorobenzene
1,4-Dichlorobenzene
Hexachloroethane
1,2-Dichlorobenzene
Hexachlorobutadiene
1,2,4-Trichlorobenzene
2-Chloronaphthalene
Hexachlorobenzene
Retention time (min.)
6.8
7.6
8.3
9.3
20.0
22.3
3.6*
10.1a
Method detection limit
(v-g/U
7.79
7.34
0.03
7.74
0.034
0.05
0.94
0.05
Column conditions: Supelcoport (80/1 OX) mesh) coated with 1.5% OV-1/2.4% OV-225 packed in a 1,8 mx 2mm
ID glass column with 5% Methane/95% Argon carrier gas at a flow rate of 25 mL/min. Column temperature,
isothermal at 75°C, except as otherwise indicated.
aColumn temperature 165°C.
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Column: 1.5% OV-1+ 1.5% OV-225
on Gas Chrom Q
Temperature: 165°C
Detector: Electron Capture
A. Hexachlorocyclopentadiene
B. 2-Chloronaphthalene
C. Hexachlorobenzene
Sample
1 Liter
Extraction
3x60 ml
MeCli
Exchange
to Hexane
K/D-10 ml
Florisil
Clean-up
1 st Fraction
200 ml
Pet. Ether
K/Dto
10 ml
EC Analysis
Figure 3.
Analytical method-category 3-
chlorinated hydrocarbons.
5 10 15
Retention Time-Minutes
Figure 2. Gas chromatogram of chlori-
nated hydrocarbons.
References
1. Guidelines Establishing Test Proce-
dures for Analysis of Pollutants, Pro-
posed Regulations. Federal Register.
44 (223): 69522-69525, Dec. 3, 1979.
2. Longbottom, J. E. and J. J. Lichten-
berg. Methods for Organic Chemical
Analysis of Municipal and Industrial
Wastewater. EPA-600/4-82-057,
USEPA, Environmental Monitoring
and Support Laboratory, Cincinnati.
July 1982.
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J. R. Florence J. R. Hall, M. Khare. S. M. Maggio. J. C. Mitchell, R. A. Solomon, J. R.
SoloRio. D. L Strother. and M. N. Wass are with IT Enviroscience, Knoxville,
TN37923.
James J. Lichtenberg is the EPA Project Officer (see below).
The complete report, entitled "Determination of Chlorinated Hydrocarbons in
Industrial and Municipal Wastewaters,"(Order No. PB 86-121 357/AS; Cost:
$ 11.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S4-85/069
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U S EtiVIR PROTECTION AGfNCY
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