微波消解-双道原子荧光分析仪联合测定土壤中砷和汞

应用AFS-9530型双道原子荧光光谱法研究土壤样品中砷和汞的联合测定技术,将土壤样品置于(1+1)王水的微波消解体系中进行消解,加入1m L 5%的重铬酸钾溶液保护汞,加入5m L(5%硫脲+5%抗坏血酸)混合液将五价砷还原为三价,以硼氢化钾为还原剂在5%盐酸介质中测定砷和汞,最低检出限为砷0.55μg/L,汞0.30μg/L,回收率砷在93.5%—105.8%之间,汞在85.5%—104.9%之间,满足准确度要求。

Determining Arsenic and Mercury in Soil with Microwave digestion Coupled with Double Channel Atomic Fluorescence Analyzer

We used AFS-9530 double channel atomic fluorescence spectrometry to determine arsenic and mercury in soil samples. Soil samples were placed in microwave digestion system of （1＋1） aqua regia, 1mL 5% potassium dichromate solution was added to protect mercury, 5mL 5% thiourea and 5% ascorbic acid mixture were added to deacidize pentavalent arsenicreduction to trivalent. Arsenic and mercury were determined in 5% hydrochloric acid medium with potassium borohydride as deoxidizer. The minimum detection limit of arsenic and mercury were 0.55g/L and 0.30 g/L. The recovery rate of arsenic was 93.5%-105.8%, the recovery rate of mercury was 85.5%-104.9%, met the accuracy requirement.