选择以碱溶液为消解体系,通过对氯化镁加入方式、消解温度、消解时间等样品前处理条件进行探讨确立了最佳消解条件,选用合适的内标元素及干扰扣除,建立了电感耦合等离子体质谱法快速测定土壤中6价铬的分析方法。6价铬的质量浓度在1.0 mg/L以内与对应的信号强度呈线性关系,相关系数为0.999 9,方法检出限为0.11 mg/kg,测定下限为0.44 mg/kg。按照试验方法对国家标准物质中的6价铬进行测定,测定值与认定值一致,相对标准偏差RSD(n=6)为0.98%~2.81%,通过对实际样品进行加标回收试验,回收率为94%~105%。该方法具有稳定性好、准确度高,适用于土壤样品中痕量6价铬的分析。

Taking alkaline solution digestion as the pre-treatment method,the optimal digestion conditions are determined through exploring the sample pre-treatment conditions such as magnesium chloride addition way,digestion temperature,and digestion time.The appropriate internal standard elements and interference deductions are selected out,and an analytical method is established for rapid determination of hexavalent chromium in soil by inductively coupled plasma mass spectrometry.The mass concentration of hexavalent chromium is linearly related to the corresponding signal intensity within 1.0 mg·L^-1,with a correlation coefficient of 0.999 9.The detection limit of the method is 0.11 mg·kg^-1,and the lower limit of the determination is 0.44 mg·kg^-1.According to the experimental method,hexavalent chromium in China's national standard substances is determined,and the measured value is consistent with the recognized value.The relative standard deviation (n=6) is 0.98%-2.81%.By conducting spiked recovery experiments on actual samples,the spiked recovery rate ranges from 94% to 105%.The established determination method has good stability and high accuracy,suitable for the analysis of trace hexavalent chromium in soil samples.

李小辉(1982-),女,硕士,高级工程师,研究方向为地质及环境样品分析,通讯联系人,122825954@qq.com。