微波消解-电感耦合等离子体质谱法测定水系沉积物中砷的含量及其方法比对研究

Determination of arsenic in soil and sediments by ICP-MS combined with microwave digestion and comparison with national standard method

采用微波消解-电感耦合等离子体质谱(ICP-MS)法测定水系沉积物和土壤中砷的含量。样品消解采用重金属全量酸消解法,进入ICP-MS直接测定,结果得到砷元素校正曲线的相关系数0.9997,检出限0.001 mg/kg,标准样品的测定值都在保证值范围内,环境样品测定的相对标准偏差均低于5%,加标回收率在92%~110%。同时采用国家标准方法王水消解-原子荧光光度法验证了方法的准确度,两种方法测定结果数据一致性好,相对偏差均在6%以内。实验结果表明,该方法具有简便、污染小、检出限低、线性范围广等特点,可用于沉积物和土壤中砷含量的测定。

In this study,we used a new method to determine the arsenic in soil and sediments. Samples were digested by microwave,and then determined by the inductively coupled plasma-atomic-mass spectrometry( ICP-MS) directly. The results showed that the correlation coefficient was0. 9997 for the arsenic working curve,and detection limit was 0. 001 mg / kg,the tested values for the standard samples fell in the scope of guarantee value,the relative standard deviations were all less than 5%,and recoveries were from 92. 0% to 110%.Comparing the microwave digestion-ICP-MS with the national standard method Aqua regia digestion-atomic fluorescence spectrometry( AFS),the results of the 2 methods had no significant difference and relative deviation was within 6%. So we concluded that the ICP-MS method combined with microwave digestion sample preparation was of simple operation,less pollution generation,and could produce good detection limit and linear range,thus it was a suitable method for the determination of arsenic content in soil and sediments,and it also could be used for simultaneous determination of a variety of other heavy metal elements.