电感耦合等离子体-质谱法测定上海市售大米中40种元素含量

Determination of 40 kinds of elements in rice sold in Shanghai by inductively coupled plasma-mass spectrometry

中文关键词:  电感耦合等离子体质谱法  大米  元素  微波消解

英文关键词:inductively coupled plasma-mass spectrometry  rice  element  microwave digestion

中文摘要:

      目的 建立电感耦合等离子体-质谱法(inductively coupled plasma-mass spectrometry, ICP-MS)测定大米中40种元素含量的分析方法。方法 采用5 mL浓硝酸、2 mL过氧化氢作为消解酸进行微波消解前处理, 选取合适的待测元素质量数和在线内标法消除质谱干扰和非质谱干扰, 内标法进行测定。结果 线性相关系数均大于0.9995, 检出限(limits of detection, LOD)为0.0001~0.3 mg/kg, 定量限(limits of quantification, LOQ)为0.0003~1.0 mg/kg。3个水平加标回收率为85.6%~121.6%, 相对标准偏差为0.5%~9.0% (n=6)。选择国家标准物质大米(national standard substance rice-1, GSB-1)验证方法的可靠性, 待测元素测定值与标准值基本一致。选取国标中原子吸收、原子荧光光谱法与电感耦合等离子体质谱法比对以验证方法准确性, 4种元素的标准样和检测样比对结果均一致。结论 该方法简便快速、准确度好、灵敏度高, 线性范围广、精密度好, 适用于大米中40种元素的同时测定。

英文摘要:

      Objective To establish a method for the determination of 40 kinds of elements in rice by inductively coupled plasma mass spectrometry. Methods Microwave digestion with nitric acid (5 mL) and hydrogen peroxide (2 mL) was used for pretreatment, choosing appropriate mass number to be measured and on-line internal standard method were used to eliminate the mass spectral interference and non-mass spectral interference. The internal standard method was used for determination. Results The linear correlation coefficients were all above 0.9995, the limits of detections (LODs) were 0.0001?0.3 mg/kg, the limits of quantifications (LOQs) were 0.0003?1.0 mg/kg, the recoveries of samples at 3 levels were 85.6%?121.6% (n=6) and the relative standard deviations (RSD) were 0.5%?9.0%. The national standard substance rice (GSB-1) was selected to verify the realiability of the method. The measured values of elements were basically within the allowable ranges of the standard values. National standards for food safety were selected to verify the accuracy of the method by comparing determination results of atomic absorption spectrometry, atomic fluorescence spectrometry with inductively coupled plasma mass spectrometry. The comparison results of standard sample and test samples of the four elements were consistent. Conclusion This method is simple, rapid, accurate, sensitive, with wide linear range and good precision, which can be applied for simultaneous detection of 40 kinds of elements in rice.