王水水浴消解-原子荧光法测定土壤中的砷和汞

Determination of Arsenic and Mercury in Soil Dissolved by Aqua Regia in Water Bath Digestion-Atomic Fluorescence Spectrometry

采用王水水浴消解-原子荧光法测定土壤样品中砷和汞,探讨消解环境、载液特性、溶液基体和还原剂硼氢化钾等因素对土壤样品中砷和汞含量测定的影响,确定了最优分析条件:土壤样品敞开消解,时间2h,期间摇动3次,用盐酸溶液(5+95)定容,混匀静置过夜,砷和汞还原剂硼氢化钾的质量分数分别为2%和0.02%,载液均为盐酸溶液(5+95)。该方法将土壤环境监测样品中砷、汞元素同步消解前处理,简化了试验步骤,节约了分析测试时间,提高了分析效率,利于处理大批量土壤样品。选取部分GSS系列标准物质进行测试试验,试验结果的精密度和准确度均可满足土壤环境监测技术规范的要求,对2种未知土壤样品进行加标回收试验,土壤样品的加标回收率:砷为94.00%~100.40%,汞为86.40%~106.80%。

This paper analyzes the factors influencing the determination of arsenic and mercury in soil samples by Aqua Regia in Water Bath-Atomic Fluorescence Spectrometry (AFS),discusses the effect of digestion environment,carrier charactevistics,solution matrix and reductant on the determination of arsenic and mercury in soil samples,and determines the optimal analytical conditions as follows:open digestion of soil samples,time 2h,shaking 3 times during the period.Then the volume is adjusted to a constant volume with hydrochloric acid solution (5+95),mixing and staying overnight and the mass fractions of arsenic and mercury reducing agents potassium borohydride are 2% and 0.02%,respectively.The method pre-processes the arsenic and mercury elements,simplifies the test procedure,saves the analysis and test time of the environmental monitoring sample,improves the analysis efficiency,and is convenient for processing large-volume soil samples.The paper selects some GSS series standard materials for testing.The precision and accuracy of the test results can meet the requirements of soil environmental monitoring technical specifications,and then the paper spikes and recovers two kinds of unknown soil samples with the following weighted recovery rate:arsenic is 94.00%~100.40%,and mercury is 86.40%~106.80%.