Determination of arsenic and antimony in geological materials and natural waters by coprecipitation with selenium and neutron activation—γ-spectrometry

Abstract

A simple, quantitative method for collecting arsenic and antimony from the digests of geological materials and from salt and fresh waters is described. The procedure involves the addition of selenium(IV) to an acidified sample followed by precipitation of selenium by tin(II) chloride. The precipitate is collected, dried, and irradiated. Arsenic and antimony are quantified directly from the activities of 76As and 122Sb, respectively. The method has detection limits of 9 ng As and 12 ng Sb per gram of rock or 500 g of water, and has been applied to eight new reference standards from the U.S. Geological Survey. Gold is quantitatively collected by the same procedure.