采用氢化物发生-原子荧光光谱法测定海产品中总砷的含量。样品经硝酸-高氯酸(4+1)混合酸消解,样品溶液中加入硫脲和抗坏血酸混合溶液作为预还原剂。于盐酸(5+95)溶液中加入10 g·L-1硼氢化钾-5 g·L-1氢氧化钾溶液使与溶液中砷离子反应生成氢化物。分析时采用载气流量为400 mL·min-1,屏蔽气流量为800 mL·min-1。砷的质量浓度在20 μg·L-1以内与荧光强度呈线性关系,方法的检出限(3s/k)为0.015 μg·L-1。应用此法对3种海产品进行分析,测定值的相对标准偏差(n=6)在3.4%~4.2%之间,回收率在98.5%~101.0%之间。

HG-AFS was applied to the determination of total amount of arsenic in seafood. Sample was digested with mixed acid of HNO3-HClO4(4+1), and prereduced with mixed solution of thiourea and ascorbic acid. Hydride of As(Ⅲ) were generated from HCl(5+95) solution using solution of 10 g·L-1 KBH4 dissolved 5 g·L-1 KOH solution as reducing reagent. Flow-rates of 400 mL·min-1 for the carrier gas and 800 mL·min-1 for the shielding gas were taken in analysis. Linear relationship between the fluorescence intensity and mass concentration of As was found in the range within 20 μg·L-1, with detection limit (3s/k)of 0.015 μg·L-1. Using 3 samples of seafood as matrixes, tests for recovery and precision were made by standard addition method, values of recovery and RSD′s (n=6)found were in the range of 98.5%-101.0% and 3.4%-4.2% respectively.