ASTM D7572-13

5.1 This guide is intended as a means for obtaining an extract from mine rock and soil samples to measure cyanide content in the aqueous portion of the sample on a dry weight basis. 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.

5.2 This guide 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 mine rock or soil.

5.3 This guide is not intended to simulate actual site leaching conditions.

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

5.5 This guide uses a comparative test method and is intended for use as a routine method for monitoring mine rock and soils. It is assumed that all who use this guide 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.

5.6 This guide identifies proper methods for obtaining mine rock and soil samples for the specific purpose of measuring cyanide concentrations.

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 guide 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 guide can also be applied to other analytical methods for cyanide, for example, US EPA Method 335.4.

1.3 The procedure options methods appear in the following order: