微波消解-DRC-ICP-MS测定富硒农产品中硒

Analysis of Selenium in Selenium-Rich Agricultural Products by ICP-MS with Dynamic Reaction Cell

为有效减少富硒农产品样品中硒元素在前处理过程中的损失、增加测定灵敏度、消除质谱法测定过程中的多原子离子干扰,研究建立一种微波消解-应用动态反应池电感耦合等离子体质谱(DRC-ICP-MS)检测富硒农产品中硒含量的检测方法。采用乙醇为增感剂,甲烷为反应气,通过优化甲烷流量、低质量截取(RPq)、乙醇体积分数,有效消除测试过程中的质谱干扰。结果表明,当以^(80)Se为目标分析物,在甲烷反应气流量0.6 mL/min,RPq 0.5,乙醇体积分数4%条件下,方法检出限为0.002 mg/kg,其对香菇粉、孜然粉和茶叶3种国家标准物质中硒含量的测定的回收率介于91%~108%之间,测定值与标准值相吻合。实际样品测定结果显示,微波消解-DRC-ICP-MS法与原子荧光法的测定结果相比无显著差异,说明该方法在富硒农产品中硒含量的测定中有较好应用前景。

In order to reduce the loss of selenium in selenium-rich agricultural product samples during the pre-treatment process,to enhance the sensitivity of determination,and to eliminate multi-atomic ion interference during mass spectrometry analysis,a detection method for selenium content in selenium-rich agricultural products using microwave digestion combined with dynamic reaction cell inductively coupled plasma mass spectrometry(DRC-ICP-MS)is established.Ethanol is used as a sensitizer,and methane is used as the reaction gas.By optimizing the methane flow rate,low mass cutoff(RPq),and the ratio of ethanol,the mass spectrometry interference during the test is effectively eliminated.Experimental results show that when ^(80)Se is the target analyte,with a methane reaction gas flow rate of 0.6 mL/min,an RPq of 0.5,and an ethanol addition ratio of 4%,the method’s detection limit is 0.002 mg/kg.The recovery rates of selenium content determination in mushroom powder cumin powder and tea standard materials are between 91%and 108%.The differences of the results of Se in actual samples determined by DRC-ICP-MS and atomic fluorescence spectrometry are not significant.This method has a good application prospect in the determination of selenium content in selenium-rich agricultural products.