ASTM D4193-95
(Test Method)Standard Test Method for Thiocyanate in Water
Standard Test Method for Thiocyanate in Water
SCOPE
1.1 This test method covers the determination of dissolved thiocyanate in water, waste water, and saline water in the range from 0.1 to 2.0 mg/L. For higher concentrations, use an aliquot from the diluted sample.
1.2 This test method has been used successfully with reagent grade, natural, and treated sanitary effluent waters. It is the user's responsibility to assure the validity of the test method on any untested matrices.
1.3 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. For specific hazards, see Section 9.
General Information
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Standards Content (Sample)
Designation: D 4193 – 95
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
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Thiocyanate in Water
This standard is issued under the fixed designation D 4193; 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.
1. Scope method, refer to Terminology D 1129.
1.1 This test method covers the determination of dissolved
4. Summary of Test Method
thiocyanate in water, waste water, and saline water in the range
4.1 Thiocyanate reacts with ferric ions at a pH of <2 to form
from 0.1 to 2.0 mg/L. For higher concentrations, use an aliquot
a colored complex which is determined colorimetrically at 460
from the diluted sample.
nm and adheres to Beer’s Law.
1.2 This test method has been used successfully with
4.2 Industrial wastes may be highly colored and contain
reagent grade, natural, and treated sanitary effluent waters. It is
various interfering organic compounds which must be removed
the user’s responsibility to assure the validity of the test
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by adsorption on macroreticular resin prior to analysis.
method on any untested matrices.
1.3 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
5.1 Many natural waters contain thiocyanate from organic
responsibility of the user of this standard to establish appro-
decomposition products and waste water discharges. Some
priate safety and health practices and determine the applica-
industrial wastes, such as those from the steel industry,
bility of regulatory limitations prior to use. For specific
petroleum refining, and coal gasification, may contain signifi-
hazards, see Section 9.
cant concentrations of thiocyanate. Thiocyanate per se is not
2. Referenced Documents
recognized as a toxic chemical compound. However, when
chlorinated, thiocyanate is converted to the highly toxic and
2.1 ASTM Standards:
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volatile cyanogen chloride.
D 1129 Terminology Relating to Water
5.1.1 For information on the impact of cyanogen com-
D 1192 Specification for Equipment for Sampling Water
2
pounds, see Appendix X1of Test Method D 2036.
and Steam
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D 1193 Specification for Reagent Water
6. Interferences
3
D 2036 Test Methods for Cyanides in Water
6.1 Hexavalent chromium interference is removed by ad-
D 3370 Practices for Sampling Water from Closed Con-
2
justing the pH to 2 with concentrated nitric acid and adding
duits
ferrous sulfate. Raising the pH to 8.5-9 with sodium hydroxide
D 3856 Guide for Good Laboratory Practices in Laborato-
2
precipitates Fe (III) and Cr (III) as the hydroxides, which are
ries Engaged in Sampling and Analysis of Water
removed by filtration.
D 4210 Practice for Interlaboratory Quality Control Proce-
2
6.2 Reducing agents that reduce Fe (III) to Fe (II), thus
dures and a Discussion on Reporting Low-Level Data
preventing formation of the ferric thiocyanate complex, are
E 60 Practice for Photometric and Spectrophotometric
4
destroyed by a few drops of hydrogen peroxide.
Methods for Chemical Analysis of Metals
6.3 High concentrations of cyanide in proportion to the
E 275 Practice for Describing and Measuring Performance
concentration of thiocyanate will react with the iron to form
of Ultraviolet, Visible, and Near Infrared Spectrophotom-
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colored complexes.
eters
6.4 Colored or interfering organic compounds must be
3. Terminology
removed by adsorption on macroreticular adsorption resin prior
to analysis.
3.1 Definitions—For definitions of terms used in this test
NOTE 1—Examples of interfering compounds are fluoride, phosphate,
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oxalate, arsenate, tartrate, borate, etc. which form complexes with iron.
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This test method is under the jurisdiction of ASTM Committee D-19 on Water
Production of a red color with ferric ions is typical of phenols, enols,
and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water.
Current edition approved Sept. 10, 1995. Published November 1995. Originally
e 1 6
published as D 4193 – 82. Last previous edition D 4193 – 89 (1994) . Spencer, R. R., Leenheer, J., and Marti, V. C., “Automated Colorimetric
2
Annual Book of ASTM Standards, Vol 11.01. Determination of Thiocyanate, Thiosulfate, and Tetrathionate in Water,’’ AOAC
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Annual Book of ASTM Standards, Vol 11.02. 94th Annual Meeting, Washington, DC, 1980.
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Annual Book of ASTM Standards, Vol 03.05. Newman, A. A. (ed.), Chemistry and Biochemistry of Thiocyanic Acid and Its
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Annual Book of ASTM Standards, Vol 14.01. Derivatives, Academic Press, New York, NY, 1975.
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D 4193
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oximes, and acetates.
hydrocyanic acid (HCN). All manipulat
...
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