1.1This test method covers the determination of free cyanides in waters and wastewaters. Free cyanide is here defined as the cyanide which diffuses as cyanide (HCN), at room temperature, from a solution at pH 6.
1.2This test method does not include complexes that resist dissociation, such as hexacyanoferrates and gold cyanide, nor does it include thiocyanate and cyanohydrin.
1.3This test method may be applied to water and wastewater samples containing free cyanide from 10 to 150 μg/L. Greater concentrations may be determined by appropriate dilution.
1.4This test method has been fully validated by collaborative testing as specified by Practice D2777.
1.5The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6This 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 8.6, 8.9, Section 9, and 12.2.1.