提出了一种顺序流动注射-氢化物发生-原子吸收光谱分析方法。食品样品经硝酸-高氯酸(4+1)混合酸消化,以硼氢化钾为还原剂,盐酸溶液为载流,用氢化物发生-原子吸收光谱法测定食品中铅、镉和汞含量的方法。在优化的试验条件下,铅、镉和汞的质量浓度分别在一定的范围内与其吸光度呈线性关系,检出限(3s/k)分别为0.20,0.04,0.22 μg·L-1。用此方法测定了食品中重金属铅、镉、汞的含量,测定值的相对标准偏差(n=6)均小于3.0%,加标回收率在94.8%~103.2%之间。

A method of sequential flow-injection technique hyphenated with HG-AAS was proposed. The foodstuffs sample was digested with HNO3-HClO4 (4+1) solution, and the contents of Pb, Cd and Hg were determined by HG-AAS with KBH4 as reducing reagent and HCl solution as carrying solution. Linear relationships between values of absorbance and mass concentration of the 3 elements were obtained in definite ranges, with detection limit (3S/N) of 0.20 μg · L-1 for Pb, 0.04 μg · L-1 for Cd and 0.22 μg · L-1 for Hg. The proposed method was applied to the analysis of foodstuffs, values of recovery found by standard addition method were in the range of 94.8%-103.2%, with RSD′s (n=6) less than 3.0%.