ASTM D7572-11a

This practice is intended as a means for obtaining an extract from mine rock and soil samples measure cyanide concentrations. Cyanide is analyzed in mine rock and soil extracts for measurement of cyanide concentration; however, improper sample collection and extraction can result in significant positive or negative bias, potentially resulting in unnecessary permit violations or undetected cyanide releases into the environment.

This practice is designed to mobilize aqueous cyanides present in the solids, so that the resulting extract can be used to assess leachate that could potentially be produced from remediated mine rock or soil in the field.

This practice is not intended to simulate actual site leaching conditions.

This practice produces extracts that are amenable to the determination of minor (trace) constituents. When minor constituents are being determined, it is especially important that precautions be taken in sample preservation, storage and handling to avoid possible contamination of the extracts.

This practice uses a comparative test method and is intended for use as a routine method for monitoring remediated mine rock and soils after process releases and remediation. It is assumed that all who use this practice will be trained analysts capable of performing it skillfully and safely. It is expected that work will be performed in a properly equipped laboratory applying appropriate quality control practices such as those described in Guide D3856.

1.1 This guide is applicable for the collection, extraction and preservation of extracts from mine rock and soil samples for the analysis of cyanide in the extracts. Responsibilities of field sampling personnel and the laboratory are indicated.

1.2 The sampling, preservation and extraction procedures described in this practice are recommended for the analysis of total cyanide, available cyanide, weak acid dissociable cyanide, and free cyanide by Test Methods D2036, D4282, D4374, D6888, D6994, D7237, and D7284. The information supplied in this practice can also be applied to other analytical methods for cyanide, for example, US EPA Method 335.4.

1.3 The values stated in SI units are to be regarded as standard.

1.4 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.