ASTM D4744-89(1995)e1
(Test Method)Standard Test Method for Organic Halides in Water by Carbon Adsorption-Microcoulometric Detection (Withdrawn 2002)
Standard Test Method for Organic Halides in Water by Carbon Adsorption-Microcoulometric Detection (Withdrawn 2002)
SCOPE
1.1 This test method covers the determination of the organic halides in water in concentrations from 5 to 1000 [mu]g/L. Higher halide concentrations may be determined by making an appropriate dilution.
1.2 This test method is applicable only for those organic halides that can be adsorbed by granular activated carbon (GAC). 2,3,4
1.3 This test method is applicable to samples whose inorganic halide concentration does not exceed the organic halide concentration by more than 20000 times. Chloride ion may be determined by Test Methods D512. See Section 6.
1.4 This test method was used successfully with several waters (see 14.3). It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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e1
Designation: D 4744 – 89 (Reapproved 1995)
Standard Test Method for
Organic Halides in Water by Carbon
AdsorptionMicrocoulometric Detection
This standard is issued under the fixed designation D 4744; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Section 15 was added editorially in June 1995.
1. Scope 3. Terminology
1.1 This test method covers the determination of the organic 3.1 Definitions—For definitions of terms used in this test
halides in water in concentrations from 5 to 1000 μg/L. Higher method, refer to Terminology D 1129.
halide concentrations may be determined by making an appro- 3.2 Definitions of Terms Specific to This Standard:
priate dilution. 3.2.1 organic halides—all organic species containing chlo-
1.2 This test method is applicable only for those organic rine, bromine, and iodine that are adsorbed by granular
halides that can be adsorbed by granular activated carbon activated carbon and produce titratable species under the
2,3,4
(GAC). conditions of the test method. See Section 6.
1.3 This test method is applicable to samples whose inor- 3.2.2 Since the description of organic halides is method-
ganic halide concentration does not exceed the organic halide dependent, the following descriptions are provided to simplify
concentration by more than 20 000 times. Chloride ion may be communications.
determined by Test Methods D 512. See Section 6. 3.2.3 total organic halides (TOX)—when a sample is run
1.4 This test method was used successfully with several unpurged and unfiltered, the result is called total organic
waters (see 14.3). It is the user’s responsibility to ensure the halides (TOX).
validity of this test method for waters of untested matrices. 3.2.4 nonpurgeable organic halides (NPOX)—when a
1.5 This standard does not purport to address all of the sample is purged before running, the result is called nonpurge-
safety concerns, if any, associated with its use. It is the able organic halides (NPOX).
responsibility of the user of this standard to establish appro- 3.2.5 purgeable organic halides (POX)—the difference be-
priate safety and health practices and determine the applica- tween the TOX and the NPOX is the purgeable organic halides
bility of regulatory limitations prior to use. (POX). The POX fraction may also be determined directly by
a variation of this test method.
2. Referenced Documents
3.2.6 dissolved organic halides (DOX)—when a sample
2.1 ASTM Standards: containing some solid material is filtered or centrifuged and the
D 512 Test Methods for Chloride Ion in Water
liquid portion is analyzed, the result is called dissolved organic
D 1129 Terminology Relating to Water
halides (DOX).
D 1193 Specification for Reagent Water 3.2.7 suspended organic halides (SOX or SX)—when the
D 2777 Practice for Determination of Precision and Bias of
solid material is resuspended in TOX-free water and analyzed,
Applicable Test Methods of Committee D-19 on Water the result is called suspended organic halides (SOX). Since this
test method is not designed to specifically remove inorganic
halides from suspended matter, this measurement may more
This test method is under the jurisdiction of ASTM Committee D-19 on Water properly be called suspended halides (SX). It should be noted
and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
that DOX and SX results are highly dependent upon the type of
Organic Substances in Water.
filtration or centrifugation process used.
Current edition approved Nov. 24, 1989. Published March 1990. Originally
published as D 4744 – 87. Last previous edition D 4744 – 87.
2 4. Summary of Test Method
Belford, G., “Absorption on Carbon: Theoretical Considerations,’’ Environ-
mental Science and Technology, August 1980, p. 910.
4.1 This test method consists of three steps. These are the
Dobbs, R., and Cohen, J., “Carbon Adsorption Isotherms for Toxic Organics,”
following:
EPA600/8-80-023, April 1980, National Technical Information Center, Springfield,
4.1.1 Adsorption of organics from water onto granular
VA 22161.
Fochtman, E., and Dobbs, R., Adsorption of Carcinogenic Compounds by
activated carbon (GAC) packed in microcolumns,
Activated Carbon, Activated Carbon Adsorption of Organics from the Aqueous
4.1.2 Desorption of inorganic halides by washing the GAC
Phase, Vol 1, Ann Arbor Science, Ann Arbor, MI, p. 157.
5 with nitrate solution, and
Annual Book of ASTM Standards, Vol 11.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 4744
4.1.3 Combustion of sorbed organics along with the GAC, 7. Apparatus
followed by microcoulometric titration against silver ion of 6
7.1 Adsorption Apparatus —Arrange components of the
halides thus produced.
adsorption apparatus in accordance with the schematic diagram
4.2 The procedure may be further detailed as follows:
in Fig. 1. The sample reservoir and the nitrate wash reservoir
4.2.1 First, sodium sulfite is added to a water sample to
can be made from 25.4 mm outside diameter by 300-mm long
reduce any residual chlorine to chloride. The sample is then standard wall stainless steel tubing. Interconnection of compo-
acidified to pH 2 with nitric acid to improve the adsorption of
nents can be made with swage-type tube fittings using O-ring
organics. Then, 100 mL of the acidified sample is forced at 3 ferrules and stainless steel or fluorocarbon tubing.
mL/min through two glass columns in series. Each column
7.2 Analyzer Apparatus —Analyzer apparatus consists of a
contains 40 mg of granular activated carbon (100/200 mesh). boat inlet, high-temperature furnace capable of operating at
4.2.2 Second, the two GAC columns are washed with 2 mL 800°C and a microcoulometric titrator capable of measuring at
least 100 ng of halide as hydrogen halide (HX) by silver ion
of a reagent containing 5000 mg/L of nitrate ion in water. This
reagent removes inorganic halides from GAC. titration, as shown schematically in Fig. 2.
4.2.3 Third, after the adsorption and wash steps, each GAC
8. Reagents and Materials
portion is analyzed for halides using controlled atmosphere
8.1 Purity of Reagents—Reagent grade chemicals shall be
combustion and microcoulometric detection.
used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to the specifications of the Commit-
5. Significance and Use
tee on Analytical Reagents of the American Chemical Society,
5.1 Organic halides typically do not occur in natural waters 8
where such specifications are available. Other grades may be
at concentrations greater than 5 μg/L. A TOX level of greater
used, provided it is first ascertained that the reagent is of
than 5 μg/L is generally indicative of contamination by
sufficiently high purity to permit its use without lessening the
synthetic organics. Accordingly, this test method may be used
accuracy of the determination.
to follow the occurrence, production, and removal of haloge-
8.2 Purity of Water—Unless otherwise indicated, references
nated organic contaminants in water and wastewater.
to water shall be understood to mean reagent water conforming
5.2 When applied to chlorinated drinking water, this test
to Specification D 1193, Type I.
method can be used to follow the production of TOX, which
NOTE 1—Caution: Water that conforms to this specification may still
results from the chlorination of naturally occurring organics.
contain significant amounts of TOX (for example, 10 to 30 μg Cl/L).
The majority of these halogenated organics are not determined
Accordingly, the TOX of the reagent water should be determined. This
by gas chromatography.
value should be taken into consideration when preparing standards and
5.3 When applied to wastewater, this test method can be making sample dilutions.
used to follow the occurrence and removal of organic halides,
many of which have been determined to be toxic.
Adsorption Apparatus (Model AD-2) available from Dohrmann, Santa Clara,
CA, has been found suitable. Also an equivalent may be used.
5.4 When applied to waters from monitoring wells around
Analyzer Apparatus (Model MC-1) available from Dohrmann, Santa Clara, CA,
hazardous waste dump sites, the measurement of dissolved
has been found suitable. Also an equivalent may be used.
organic halides (DOX) can be used to follow the movement of 8
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
this class of contaminant through the groundwater system.
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
6. Interferences and Limitations
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD.
6.1 Chloride Ion—The nitrate wash step is effective for
removing inorganic halide from the activated carbon. However,
to minimize the impact of unremoved inorganics on the TOX
results, the ratio of inorganic to organic halide concentration in
the sample should not exceed 20 000.
6.2 Halogens Other than Chlorine—Fluorinated com-
pounds are not detected by this test method, since they do not
produce species titratable against silver ion.
6.2.1 Brominated and iodinated compounds make a contri-
bution that is affected by two considerations:
6.2.1.1 The instrument is calibrated with a chlorinated
compound, so no allowance is made for the different atomic
mass of bromine and iodine;
6.2.1.2 Not all of these two elements are converted to
titratable species. The combination of these effects results in
about 25 % of the bromine and about 15 % of the iodine
appearing as “chlorine.’’ Brominated and iodinated organics
are rarely found in water, so this recovery level is not usually
of significance. FIG. 1 Schematic of Adsorption Apparatus
D 4744
9. Sampling and Sample Preservation
9.1 This sampling procedure assumes that both purgeable
organic halides and residual chlorine may be present. Keep in
mind that more than 100 mL (for example, 125 mL) of sample
may be required for each replicate analysis.
9.2 Add to a suitably sized clean glass container a sufficient
amount of nitric acid to bring the sample to an approximate pH
FIG. 2 Analyzer Apparatus
of 2. Also, add sufficient sulfite solution to reduce any residual
chlorine that may be present in the sample. This will typically
be in the range of 0.2 mL/100 mL of sample. Collect a
8.3 Acetic Acid in Water, 70 %—Dilute 7 volumes of acetic
representative sample in the glass container, being careful to
acid with 3 volumes of water.
completely fill it. Cap the container with a screw cap that is
8.4 Carbon Dioxide, purity 99.99 %.
9 lined either with aluminum foil or TFE-fluorocarbon to reduce
8.5 Cerafelt Refractory Fiber Felt—Form this material
sorption of slightly soluble organic halides.
into plugs to hold the GAC in the adsorption columns.
9.3 If the sample cannot be analyzed within a few days,
NOTE 2—Caution: Be sure to rinse fingers of excess chlorides before
store it at 2 to 4°C to further ensure sample integrity. Maximum
forming plugs.
holding time should be 7 days.
8.6 Granular Activated Carbon (100 to 200 mesh) —The
GAC used should meet the performance criteria outlined in 10. Apparatus Adjustments
Annex A1. The carbon as received should be ground and
10.1 Adsorption Apparatus—Adjust gas pressures such that
sieved. A100- to 200-mesh cut should be selected for use.
a water sample will move through the GAC adsorption
columns at approximately 3 mL/min and that nitrate wash will
NOTE 3—Caution: Grind and sieve carbon in an area free of haloge-
flow through the GAC columns at approximately 0.5 mL/min.
nated organic vapors. Also, protect the ground GAC from all sources of
halogenated organic vapors. 10.2 Analyzer Apparatus—Follow manufacturer’s instruc-
tions for operation of the analyzer apparatus.
8.7 Granular Activated Carbon (GAC) Columns—Place 40
mg of GAC (100 to 200 mesh) into each of two glass columns
11. Calibration Check
that are 2-mm inside diameter by 6-mm outside diameter by
11.1 TOX Blank—Since the reagent water used may contain
50-mm long. Hold the GAC in place with plugs of refractory
significant amounts of TOX it should not be depended upon to
fiber felt.
establish method blank. It has been found that the TOX of the
NOTE 4—Caution: Protect these columns from all sources of haloge-
GAC taken through the nitrate wash and halide determination
nated organic vapors. Storage in TOX-free water is a good way to
steps can be used as a reliable measure of method blank.
accomplish this.
Accordingly, make replicate TOX measurements on 40-mg
8.8 Nitrate Wash Solution (5000 mg/L NO )—Prepare a
portions of GAC that have been put through the nitrate wash
nitrate wash solution by transferring approximately 8.2 g of
step. The average of these values should be used as C in the
potassium nitrate into a 1-L volumetric flask. Dilute to volume
calculation section. This procedure must be performed at least
with water.
once a day, and preferably also at the end of a group of sample
8.9 Nitric Acid (sp gr 1.42)—Concentrated nitric acid.
runs. If experience shows a substantial variation over this time
8.10 Oxygen, purity 99.99 %.
interval, the blank determination must be made more often.
8.11 Reagent Water—Reserve a portion of the water used to
The two pairs of blanks bracketing a set of samples should be
prepare the calibration standard and any sample dilutions. The
averaged, and that value for C applied to the sample set.
background TOX in this water should be determined and used
11.2 Make duplicate determinations of TOX in the calibra-
in subsequent calculations.
tion standard and the reagent water used to prepare the
8.12 Sodium Sulfite Solution (0.1 M)—Prepare a sodium
calibration standard. The net response to the calibration stan-
sulfite solution by transferring approximately 10.3 g of sodium
dard (TOX of calibration standard-TOX of reagent water)
sulfite to a 1-L volumetric flask. Dilute to volume with water.
should be within 5 % of the prepared value of the calibration
8.13 Trichlorophenol Solution, Stock (10 g Cl/L)—Prepare
standard.
a stock solution by weighing accurately 1.856 g of trichlo-
rophenol into a 100-mL volumetric flask. Dilute to volume
12. Procedure
with methanol.
12.1 Adjust pH of the sample to approximately 2 with
8.14 Trichlorophenol Calibration Standard (1000 μg Cl/
concentrated nitric acid if not already
...
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