称取0.250 0 g样品,以2.5 mL盐酸、2.5 mL硝酸、2.5 mL氢氟酸和5 mL高氯酸为酸体系,设置消解温度为110~150℃;消解结束后,趁热加入盐酸(还原剂)5 mL和10 g·L^-1三氯化铁溶液(掩蔽剂)5 mL,再用水稀释至25 mL,得到待测样品溶液,采用氢化物发生原子荧光光谱法测定其中全硒的含量。结果显示:硒的质量浓度在20.00 μg·L^-1以内与其对应的响应值呈线性关系,检出限(3s/k)为0.06 μg·L^-1;对岩石、土壤和水系沉积物国家标准物质进行验证,测定值的相对标准偏差(n=6)为0.68%~2.5%,回收率为94.0%~110%。

Hydrochloric acid (2.5 mL), nitric acid (2.5 mL), hydrofluoric acid (2.5 mL) and perchloric acid (5 mL) were used as acid system, and 0.250 0 g of the sample was digested at 110-150 ℃. After digestion, 5 mL of hydrochloric acid as the reductant and 5 mL of 10 g·L^-1 ferric chloride solution as the masking agent were added when it was hot, and the sample solution obtained was diluted to 25 mL with water for test, in which total selenium was determined by hydride generation atomic fluorescence spectrometry. As shown by the results, linear relationship between mass concentration of selenium and its response value was kept within 20.00 μg·L^-1, with detection limit (3s/k) of 0.06 μg·L^-1. The national standard substances of rock, soil and stream sediment were verified, and RSDs of the determined values were ranged from 0.68% to 2.5%, with values of recovery in the range of 94.0%-110%.