电感耦合等离子体质谱法测定米豆腐中5种元素的含量

Determination of 5 kinds of elements in rice tofu by inductively coupled plasma mass spectrometry

目的建立电感耦合等离子体质谱法同时测定米豆腐中铅、砷、汞、镉、铬5种有害元素含量的分析方法。方法样品经微波消解,超纯水定容,以锗、铟、铋为内标物质,用电感耦合等离子体质谱法同时测定铅、砷、汞、镉、铬。结果铅、砷、汞、镉、铬回收率分别为83.2%~92.5%、85.3%~93.2%、83.5%~95.2%、85.7%~94.0%、81.7%~96.0%,相对标准偏差(n=6)分别为3.7%、2.3%、3.1%、2.9%、3.9%。5种元素线性关系良好,相关系数(n=6)在0.9997~1.000。结论优化了样品前处理方法和仪器参数,可用于米豆腐中铅、砷、汞、镉、铬的测定。

Objective To establish a method for simultaneous determination of lead, arseni, mercury, cadmium and chromium in rice tofu by inductively coupled plasma mass spectrometry（ICP-MS）. Methods The sample was digested by microwave, and the solvent was ultra pure water. Germanium, indium and bismuth were used as internal standards for simultaneous determination of lead, arsenic, mercury, cadmium andchromium by inductively coupled plasma mass spectrometry. Results The average recoveries of lead, arsenic, mercury, cadmium and chromium were 83.2%~92.5%, 85.3%~93.2%, 83.5%~95.2%, 85.7%~94.0%, 81.7%~96.0%, respectively, while the relative standard deviation（n=6） was 3.7%, 2.3%, 3.1%, 2.9%, 3.9%, respectively. Five kinds of elements all showed good linear range, and the correlation coefficients were 0.9997~1.000（n=6）. Conclusion The sample pretreatment method and instrument parameters were optimized. It can be used for the determination of lead, arseni, mercury, cadmium and chromium in rice tofu.