微波消解-电感耦合等离子体原子发射光谱法测定稻米中钼元素含量

ICP-AES Determination of Molybdenum in Rice with Microwave Digestion

摘要: 稻米样品经硝酸微波消解后，采用电感耦合等离子体原子发射光谱法（ICP-AES）测定稻米中钼的含量。选择波长为202.03 nm的谱线作为测定钼的分析线。钼元素的质量浓度在10.0~80.0 μg·L^-1内与其对应的响应值呈线性关系，方法检出限（3s）为0.05 mg·kg^-1。应用此法测定大米粉标准物质中钼元素的含量，测定值的相对标准偏差（RSD，n=7）为1.8%，与认定值一致。在3个浓度水平下进行加标回收试验，回收率为93.8%~105%。

Abstract: The rice sample was digested with HNO₃ by microwave digestion and the content of molybdenum in sample solution was determined by ICP-AES. Wavelength of 202.03 nm was selected as analytical spectral line for determination of molybdenum. Linearity relationship between values of mass concentration of molybdenum and its response was kept in the range of 10.0-80.0 μg·L^-1, with detection limit (3s) of 0.05 mg·kg^-1. The proposed method was used in the determination of molybdenum in rice flour standard, giving RSD (n=7) of determined values of 1.8%, and the results obtained were in conformity with certified values. At three spike levels, values of recovery were found in the range of 93.8%-105%.