1.1 This practice is used for the preparation an extract of solid waste and soil samples by alkaline extraction for determination of total cyanide. Simple cyanide (CN-) salts of Groups 1 and 2 (alkali and alkaline earth) metals; soluble alkali and alkaline earth salts of zinc, copper, cadmium, mercury, nickel, silver, and iron cyanide complexes; and insoluble metal-metal cyanide complexes, such as Prussian Blue, are quantitatively recovered. Gold, platinum group metals, and cobalt cyanide complexes are not recovered during analysis. 1.2 Cyanide complexes are extracted into an alkaline solution. 1.3 Analysis with ligand injection and the ultraviolet (UV) irradiation source turned off determines the weak and dissociable (WAD) and available cyanide concentration in the extract. NOTE 1--Free cyanide cannot be determined because of the change of equilibrium conditions during the extraction process. 1.4 The applicable range of the practice is 0.5 to 100 mg/Kg using a 200 uL sample loop for Test Method D7511. Extend the range to higher concentrations by dilution or by using a smaller sample injection volume. 1.5 This practice can be used by experienced analysts experienced with equipment using segmented flow analysis (SFA) and flow injection analysis (FIA) or working under the close supervision of such qualified persons. 1.6 Units--The values stated in SI units are to be regarded as the standard. No other units of measure are included in this standard. 1.7 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 applicability or regulatory limitations prior to use. Specific hazard statements are given in Section 9.
Current cyanide methods for total cyanide in solid waste rely on a preliminary acid distillation followed by titration or colorimetric tests. Acid distillations do not quantitatively recover the strong metal metal cyanide complexes. The U.S. EPA has ruled that strong metal metal cyanide complexes are included in the definition of total cyanide; therefore, the results based on preliminary acid distillation are biased low. This practice will rapidly and quantitatively extract all inorganic cyanide complexes including those not quantitatively recovered by distillation. This practice then allows measurement of cyanide by Test Method D7511. Elimination of distillation shortens analysis times allowing more samples to be tested per day and lowering the cost of analysis.
Keywordsamperometry; cyanide; cyanide amenable to chlorination; flow injection analysis; free cyanide; gas diffusion membrane; ligand exchange; silver electrode; total cyanide; weak acid dissociable cyanide
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development