称取0.100 0 g烘干后的样品,以盐酸-磷酸-氢氟酸-硝酸-高氯酸为酸体系对其进行消解,消解结束后加入20 mL盐酸,用水定容至200 mL,采用电感耦合等离子体原子发射光谱法测定钨、钼、铋的含量。设置射频功率为1 150 W,雾化气流量为0.50 L·min^-1,辅助气流量为1.00 L·min^-1,钨、钼、铋的分析谱线依次为239.7,202.0,223.0 nm。结果显示:钨、钼、铋的质量浓度在一定范围内与其对应的响应值呈线性关系,检出限为0.002 4%~0.003 8%;对矽卡岩型多金属钨矿标准物质进行分析,测定值与认定值相对误差的绝对值不大于7.7%,测定值的相对标准偏差(n=12)不大于5.5%;对实际样品进行加标回收试验,回收率为96.2%~101%;采用本法与国家标准方法对样品进行分析,钨、钼、铋的测定值基本一致。

The dried sample (0.100 0 g) was digested with hydrochloric acid-phosphoric acid-hydrofluoric acid-nitric acid-perchloric acid as acid system. After digestion, 20 mL of hydrochloric acid was added and water was used to make its volume up to 200 mL. W, Mo and Bi were determined by inductively coupled plasma-atomic emission spectroscopy. The radio frequency power was set to 1 150 W, with the atomizing gas flow of 0.50 L·min^-1, the auxiliary gas flow of 1.00 L·min^-1. The spectral lines of W, Mo and Bi were 239.7, 202.0 nm and 223.0 nm, respectively. It was shown that linear relationships between values of mass concentration of W, Mo and Bi and their response values were kept in the definite ranges, with detection limits in the range of 0.002 4%-0.003 8%. The standard substances of skarn-type polymetallic tungsten ore were determined, and the absolute values of relative errors between the determined values and the certified values were less than 7.7%, with RSDs (n=12) of the determined values less than 5.5%. Test for recovery was made on the actual sample, giving results in the range of 96.2%-101%. The determined values of W, Mo and Bi were basically consistent by this method and the national standard methods.