微波消解顺序注射冷蒸汽原子荧光光谱法测定沉积物中的痕量汞

Determination of Trace Amounts of Mercury in Sediments by Sequential Injection Cold Vapor Atomic Fluorescence Spectrometry Coupled with Microwave-Assisted Digestion

提出采用密闭微波消解结合顺序注射冷蒸汽原子荧光光谱法快速测定沉积物中痕量汞的新方法。利用10%HCl-50%HNO3-40%H2O和30%HCl-20%HNO3-50%H2O两种消解体系在140℃条件下消解5min,沉积物样品消解完全,且样品消解过程中痕量汞无损失。优化条件下,线性范围0.02～30ng.mL-1,检出限为0.5ng.g-1,RSD为3.7%(n=10)。标准参考物质GSD-2,GSD-9及GSD-10的测定值与推荐值吻合,实际样品加标回收率(91.2±4.3)%～(96.5±4.6)%。本法试剂用量少,快速准确,灵敏度高,线性范围宽,适合沉积物中的痕量汞的测定,有很好的实用价值。

A novel method for the determination of trace amounts of mercury in sediments by sequential injection cold vapor atomic fluorescence spectrometry coupled with microwave assisted digestion was developed in this paper. Satisfactory results were found when the digestion was carried out at 140℃ for 5 rain by using 10%HC1-50%HNOa-40%H20 or 30%HC1-20%HNO3- 50%0H20 media. The linear range was 0. 02-30 ng · mL -1 with detection limit of 0.5 ng· g-1. Relative standard deviation for the complete procedure of the analysis of 10 digested sediment samples was 3.70%. Recoveries of the spiked samples were between （91.2＋4. 3）% and （96. 5-＋4. 6）% The analytical results for three certified reference materials GSD-2, GSD-9 and GSD- 10 were consistent with the certified values. The method has been successfully applied to six natural sediment samples. The results indicated that the method was rapid, highly sensitive and precision, and suitable for the determination of trace amounts of mercury in sediment samples.