United States
Environmental Protection
Agency
Environmental Monitoring and
Support Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S4-85/011 Mar. 1985
ŁEPA Project Summary
Evaluation of Methods for the
Determination of Total Organic
Halide in Water and Waste
T. F. Cole
Various methods were evaluated for
determining the total organic halides
(TOX) in groundwater and in waste oil
samples. From three inorganic halide
species generation approaches and
three inorganic halide determinative
techniques evaluated for groundwater
analyses, one combined approach,
which used Schoeniger flask oxidation
with colorimetric chloride determina-
tion, was chosen for laboratory valida-
tion and method detection limit (MDL)
studies. Groundwater samples were
also analyzed for TOX using EPA Meth-
od 9022, "TOX by Neutron Activation
Analysis."
The Schoeniger flask/colorimetric
chloride and neutron activation analysis
methods gave TOX results for spiked
groundwaters comparable to those ob-
tained using Interim Method 450.1 at
halide levels above O.2 mg/L.
Oil sample analysis using the sodium
biphenyl reagent and a colorimetric
chloride method was found to be unsat-
isfactory for the analysis of various oils
spiked with PCBs due to interferences
in the colorimetric determinative step
which resulted in recoveries greater
than 100 percent.
This Project Summary was developed
by EPA's Environmental Monitoring
and Support Laboratory. Cincinnati.
OH, to announce key findings of the
research project that is fully document-
ed in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
This program is a continuation of EPA
Contract No. 68-03-2984, "Surrogate
Methods for Priority Pollutants in Waste-
water." The objective of the work con-
ducted under this research program was
to evaluate additional direct and indirect
methods for TOX analysis.
Indirect methods evaluated included
Parr bomb oxidation, Schoeniger flask
oxidation, and sodium biphenyl dehydro-
halogenation as species-generation ap-
proaches for conversion of organic halide
to inorganic halide. The determinative
techniques evaluated for the inorganic
halide produced included ion chromatog-
raphy, chloride ion selective electrode,
and a colorimetric halide procedure. In all
cases, the sample preparation procedure
used was the charcoal adsorption tech-
nique from Interim Method 450.1. The
primary thrust of this portion of the
program was to select the best species
generation approach and best determi-
native technique, and to combine these
approaches into a TOX method for use as
a less costly alternative to the microcolor-
imetric determinative technique of Inter-
im Method 450.1.
Neutron activation analysis using the
sample preparation procedure from Inter-
im Method 450.1 was the only direct
approach evaluated. This method was
chosen for its ability to distinguish be-
tween the various halogen species at
parts-per-million levels.
In addition to these methods for the
determination of TOX in aqueous samp-
les, the sodium biphenyl reagent ap-
proach was evaluated for the analysis of
TOX in transformer oil samples. The
determinative technique for these eval-
uations was the colorimetric chloride
method used for the aqueous sample
analyses.
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Analytical Methods Evaluation
Evaluation of Oxidation
Approach
Three oxidation approaches were eval-
uated for the conversion of organic chlo-
rine to chloride ion: Schoeniger flask
combustion, Parr bomb combustion, and
sodium biphenyl dehydrohalogenation.
The reference determinative technique
for the first two comparisons was ion
chromatography (1C). For the sodium
biphenyl approach, ion chromatography
was not suitable because of interferences
caused by high nitrate concentrations,
and the ASTM D-512 colorimetric chlor-
ide procedure was used.
Schoeniger Flask Procedure
The Schoeniger flask procedure was
evaluated for halide blank levels due to
glassware, absorbing solution, sample
wrapping papers, and glassware cleaning
methods
Recovery of halide spiked onto gran-
ulated activated charcoal (GAC) and ad-
sorbed from aqueous solutions onto GAC
was also evaluated. In all spiking exper-
iments a three component spiking solu-
tion containing tetrachloroethylene,
2,4,6-trichlorophenol and bromoform was
used.
The Schoeniger flask procedure was
found to be superior to both the Parr bomb
and the sodium biphenyl reagent proce-
dures (described below) in terms of halide
recovery and halide blank levels, and was
used in conjunction with the ASTM D-
512 colorimetric method for chloride ion
for method validation.
Parr Bomb Oxidation
Procedure
The Parr bomb oxidation procedure
was evaluated for halide blank levels
from apparatus and reagents, recovery of
halide spiked onto GAC, and effect of
absorption time after sample ignition. The
Parr bomb procedure was unsuitable for
halide analysis because of incomplete
combustion of the GAC and associated
poor halide recovery.
Sodium Biphenyl Reagent
Procedure
The sodium biphenyl reagent procedure
was evaluated for halide recovery for
standards in methanol and for standards
spiked onto GAC and in reagent water.
Blank halide levels associated with the
reagents and glassware were also invest-
igated.
The sodium biphenyl procedure was
found to be unsuitable because of high
halide blank levels associated with the
reagent; also, the extraction procedure
was found to be too difficult for routine
use due to the presence of the GAC at the
interface between the organic and
aqueous phases in the separatory funnel.
Evaluation of Determinative
Technique
Three determinative techniques were
evaluated: ion chromatography, chloride
ion specific electrode (ISE), andthe ASTM
D-512 colorimetric chloride procedure.
Ion Chromatography
1C was evaluated using a Dionex S2
column over two chloride concentration
ranges: 0.1 to 0.35/ug/mL and 2.0 to 10.0
/ug/mL In addition, the linearity of re-
sponse for chloride and bromide over the
range of 2 to 10 A/g/mL and the separation
of six common anions was evaluated with
an Si column.
The chloride response on both columns
and the bromide response on the Si
column were linear over the ranges
tested. Due to peak broadening, the
detection limit for bromide, estimated at
0.5 fjQ/mL, was much higher than that
for chloride (approximately 0.05 //g/L). In
the evaluation of anion separation, bro-
mide and nitrate ions were only partially
resolved. The high nitrate level associated
with the GAC was found to obscure small
amounts of bromide and to render 1C
ineffective for halide speciation in GAC
digests from the Schoeniger flask oxida-
tion procedure.
Ion Specific Electrode
The ISE determinative technique was
initially evaluated for linearity of response
over a range of 1 to 100 /yg/mL, and the
detection limit for both chloride and
bromide was found to be approximately 1
/ug/mL. ISE evaluations were stopped
when it was determined that extremely
high recoveries (>240 percent), presum-
ably due to some interference in the GAC
digest, were observed in spiked GAC
samples prepared using the Schoeniger
flask oxidation procedure.
ASTM D-512 Colorimetric
Chloride Procedure
The ASTM colorimetric procedure was
evaluated for reagent blank levels, chlo-
ride and bromide response, and the effect
of nitrate interference. The response for
both chloride and bromide was linear
from 1 to 4 /ug/mL. The estimated detec-
tion limit for both halideswasfoundtobe
approximately 0.5 /vg/mL, and nitrate
appeared to have no effect on response
Blank and spiked charcoal samples
were prepared by the Schoeniger flask
oxidation technique and analyzed by the
colorimetric procedure. Comparison of
the results of these samples with similar
results obtained with ISE and 1C showed
that ISE was least effective for halide
determination, while 1C and the color-
imetric method were essentially similar.
The colorimetric procedure was chosen
for the determinative technique for vali-
dation since the 1C method was not
capable of halide speciation with the GAC
matrix and also due to the less sophfs-
ticated and less costly nature of the
colorimetric method.
Method Validation
The MDL of the Schoeniger flask/color-
imetric halide procedure was determined
by the analyses of spiked and unspiked
replicates of reagent water according to
the standard EPA protocol. A detection
limit of 0.1 5 mg/L was calculated with an
average recovery of 57 percent.
For method validation, three identical
sets of samples were prepared and ana-
lyzed by the Schoeniger flask/colorimet-
ric procedure, EPA Method 9022 (neutron
activation analysis), and Interim Method
450.1. A summary of recovery results
obtained in these analyses is provided in
Table 1. Agreement between the methods
was good for samples which contain
halide concentrations above approximate-
ly 0.2 mg/L. Below this value, the halide
blank of the Schoeniger flask/colorimet-
ric halide procedure prevents the deter-
mination of TOX in the samples
Evaluation of EPA Method 9022
A series of spiked charcoal samples
were prepared and analyzed to evaluate
the neutron activation analysis procedure
(EPA Method 9022) as a direct method for
TOX determination. Chloride recoveries
obtained ranged from 91 percent for low-
level spiked samples to 87 percent for
high-level spiked samples. Bromide recov-
eries ranged from 90 percent for low-
level spiked samples to 88 percent for
high-level spiked samples.
Evaluation of Waste Oil
Methodology
Ten PCB-spiked oil samples obtaineo
from the Quality Assurance Branch of th€
Environmental Monitoring and Support
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Table 1 Summary of Recovery Results lor Validation Samples Obtained Using the Schoeniger
Flask TOX Method, Interim Method 450 1, and Neutron Activation Analysis Method
9022
Average Halide Amount Found
for Given Method, mg/L
Sample
Identification
Reagent water
Reagent water
Groundwater #/
Groundwater #1
Groundwater # /
Groundwater #2
Groundwater #2
Groundwater #2
Spike
Level,
mg/L
Unspiked
0.51
Unspiked
0.51
1.0
Unspiked
5 1
10.2
Schoeniger
Flask TOX
0.19
048
0.23
059
13
1.3
4.2
7.9
Interim
Method
450.1
0.020
0.43
0.044
0.56
1.3
1 7
4.0
82
Neutron
Activation
Analysis
0087
0.049
0.12
0.59
15
2.7
7.2
10.1
Average Percent Recovery
for Given Method
Schoeniger
Flask TOX
a
56
--
70
105
58
65
Interim
Method
450.1
81
-
94
120
-
45
64
Neutron
Activation
Analysis
..
78
-
92
135
--
88
72
"Not applicable.
Laboratory at Cincinnati, Ohio, were
analyzed for organic chloride content
using the sodium biphenyl reagent spec-
ies generation method and the ASTM
colorimetric chloride determinative. High
recoveries ranging from 145 percent to
268 percent were obtained for these oil
samples. To evaluate these high recov-
eries, an analytical curve study was per-
formed by spiking a PCB-f ree transformer
oil with Arochlor 1254. Results showed a
high positive bias for all samples, al-
though this bias was reduced consider-
ably with increased sample dilution.
Conclusions and
Recommendations
Based on the results of spiked reagent
water and groundwater samples ana-
lyzed, the Schoeniger flask oxidation and
colorimetric halide TOX procedure is
recommended as an alter native to Interim
Method 450.1 for use as a TOX screening
method for aqueous matrices, with the
caveat that this procedure is applicable
only to levels of TOX at or above 0.2 mg/L
in aqueous matrices. This method pro-
vides a significantly less costly alternative
for the analysis of samples which contain
low parts-per-million levels of organic
halogen and gives results comparable to
those obtained with Interim Method
450.1.
The results of the evaluation of EPA
Method 9022, Total Organic Halides by
Neutron Activation Analysis, indicate
that this direct method also is an ap-
propriate technique for TOX analysis and
offers the additional advantage of pro-
viding individual chlorine and bromine
values for the sample at levels equal to
TOX detection limits achievable with the
rnicrocoulometric determinative tech-
nique of Interim Method 450.1.
The sodium biphenyl reagent and color-
imetric halide determinative technique
for analysis of total organic chloride from
oil matrices is not suitable as a screening
procedure in its present form. Further
evaluation of the sodium biphenyl reagent
with some alternative determinative tech-
nique, such as microcoulometrictitration,
is recommended. Perhaps an additional
cleanup step for the extract prior to the
colorimetric determinative step would
establish the usefulness of this technique
at those halide levels in the range of from
20 to350jug/g.
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T F. Cole, A. M. Berry, andR. L. Wilson are withBattelle Columbus Laboratories,
Columbus, OH 43201.
Thomas A, Pressley is the EPA Protect Officer (see below).
The complete report, entitled "Evaluation of Methods for the Determination of
Total Organic Halide in Water and Waste." (Order No. PB 85-166 304/AS; Cost:
$13.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
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
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