粗金粉中金和银的联合测定

运用传统的火试金法处理粗金粉样品，建立了重量法测定粗金粉中金量、火焰原子吸收光谱法测定银量的新方法。采用留铅灰吹的方法使样品中的金银富集在1~2 g的铅合粒中，用HNO₃溶解铅合粒，然后采用重量法测定金量，火焰原子吸收光谱法于波长328.1 nm测定银量。本方法有效地解决了粗金粉中金银不能联合测定的难题，银的方法检出限为0.003 1 μg/mL。将该法用于实际样品分析，测定结果与国标法测定结果一致，金的相对标准偏差≤0.07 %，银的相对标准偏差≤1.2 %，且金和银的银回收率分别为100 %和98 %~101 %之间。

Combined determination of gold and silver in coarse gold powder

Coarse gold powders sample was processed using traditional fire assaying method.A novel method for determining gold in coarse gold powders by gravimetric method and silver by flame atomic absorption spectrometry was established.Gold and silver was enriched in 1-2 g of composite granule of lead by cupellation.The alloy was dissolved in nitric aicd,and then gold was determined by gravimetric method,silver was determined at the wavelength of 328.1 nm by flame atomic absorption spectrometry.This method resolved the problem efficiently how to combine determination of gold and silver successively in coarse gold powders.The detection limit of silver was 0.003 1 μg/mL.Relative standard deviation of gold and silver was less than 0.07 % and 1.2 %,respectively.Recovery of gold was 100 % and that of silver was in the range of 98 %-101 %.The determination results were in good agreement with those obtained by national standard method.