WAY TO PREPARE SAMPLE FOR ASSAYING Russian patent published in 2003 - IPC

FIELD: analytical chemistry, sample taking and preparation of materials in natural and industrial objects containing gold. SUBSTANCE: according to invention first fraction with grain size under 0.104 mm (I) enriched with finely dispersed gold is extracted from starting material. Its fraction of total mass is established. The rest of starting material is reduced in size to 0.2 mm or under and is divided into two fractions with grain size under 0.104 mm (II) and above 0.104 mm (III). Fractions of total mass are determined. Later analytical weight with mass of 5.0-100.0 g is sampled from each extracted fraction. Fraction material with grain size above 0.104 mm (III) is completely included in weight. Sample is so comminuted that mass of fraction with grain size above 0.104 mm (III) does not exceed 100.0 g. Content of gold in sample that includes all medium and large particles of gold is calculated by formula C = a₁C₁+a₂C₂+a₃C₃ where C is content of gold in sample, g/t; a₁,a₂,a₃ are fractions I, II, III of total mass correspondingly; C₁,C₂,C₃ is content of gold in fractions I, II, III correspondingly, g/t. EFFECT: increased authenticity of determination of content of gold in sample, reduced cost of analysis.