This test method is useful for analysis of many natural waters that contain thiocyanate from organic decomposition products and waste water discharges. Some industrial wastes, such as those from the metallurgical processing of gold ores, steel industry, petroleum refining, and coal gasification, may contain significant concentrations of thiocyanate. Thiocyanate per se is not recognized as a toxic chemical compound. However, when chlorinated, thiocyanate is converted to the highly toxic and volatile cyanogen chloride at high pH. Oxidation of thiocyanate may also release toxic hydrogen cyanide. The user of the method is advised to perform holding time studies in accordance with Practice D 4841 whenever oxidants are present in the samples.

For information on the impact of cyanogens and cyanide compounds, see Appendix X1 of Test Method D 2036.

1. Scope

1.1 This test method covers the quantitative colorimetric laboratory measurement 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.

1.1.1 Validation—This test method was validated over the range of 0.07 to 1.42 mg/L. This test method was validated at nine laboratories at four levels. This test method may be valid for reporting results down to lower levels as validated in individual user laboratories.

1.1.2 Application—This test method has been validated in reagent water, Type II, in multiple laboratories and 7 natural waters, 1 laboratory effluent, 1 steel mill effluent, and 2 dechlorinated and treated sanitary effluents in single laboratories. It is the user's responsibility to assure the validity of the test method on any untested matrices.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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 hazard statements, see Section 9.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D1129 Terminology Relating to Water

D1192 Guide for Equipment for Sampling Water and Steam in Closed Conduits

D1193 Specification for Reagent Water

D2036 Test Methods for Cyanides in Water

D2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water

D3370 Practices for Sampling Water from Closed Conduits

D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water

D4210 Practice for Intralaboratory Quality Control Procedures and a Discussion on Reporting Low-Level Data

D4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents

D5788 Guide for Spiking Organics into Aqueous Samples

D5789 Practice for Writing Quality Control Specifications for Standard Test Methods for Organic Constituents

D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis

D7237 Test Method for Free Cyanide with Flow Injection Analysis (FIA) Utilizing Gas Diffusion Separation and Amperometric Detection

D7365 Practice for Sampling, Preservation and Mitigating Interferences in Water Samples for Analysis of Cyanide

E60 Practice for Analysis of Metals, Ores, and Related Materials by Spectrophotometry

E275 Practice for Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers

Keywords

cyanide; cyanogen chloride; ferric ions; macroreticular resin (XAD-8); spectrophotometer; thiocyanate; Coal products; Colorimetric analysis--water; Cyanides; Cyanogen chloride; Decomposition; Ferric ions; Industrial water treatment; Macroreticular resin (XAD-8); Organic compounds--water; Petroleum products; Seawater (natural/synthetic); Spectrophotometry; Steel industry wastewater; Thiocyanate (soluble) content; Toxicity/toxicology--water environments; Wastewater testing/treatment;

ICS Code

ICS Number Code 13.060.50 (Examination of water for chemical substances)

Citing ASTM Standards

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