高效液相色谱-电感耦合等离子体质谱法测定 大米中无机砷

Determination of inorganic arsenic in rice by high performance liquid chromatography-inductively coupled plasma mass spectrometry

中文关键词:  高效液相色谱法  电感耦合等离子体质谱法  无机砷  形态分析

英文关键词:high performance liquid chromatography  inductively coupled plasma mass spectrometry  inorganic arsenic  morphological analysis

中文摘要:

      目的 建立高效液相色谱-电感耦合等离子体质谱法测定大米中无机砷的分析方法。方法 采用两种前处理方法对大米中的无机砷进行提取, 经高效液相色谱分离后, 利用电感耦合等离子体质谱进行测定。同时对大米样品进行微波消解后测定其中的总砷, 通过无机砷及有机砷的总和计算两种前处理方法的回收率, 从而对前处理方法进行比较。对磷酸二氢铵、碳酸铵以及磷酸氢二铵等缓冲盐进行选择, 并对pH值进行优化, 确定最优的流动相条件。结果 以12.5 mmol/L磷酸氢二铵作为流动相, 调节流动相pH为8.5, 流速为1 mL/min, 可以将5种无机砷形态完全分离。对两种前处理方法进行比较, 发现两种前处理方法的提取效率均大于87.5%, 其中酸-热辅助提取法的提取效率相对更高。结论 该方法准确、简单, 适合大米中无机砷的测定。

英文摘要:

      Objective To establish a method for determination of inorganic arsenic in rice by high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Methods Inorganic arsenic in rice was extracted by 2 kinds of pretreatment methods. After separated by HPLC, the samples were determined by ICP-MS. At the same time, the total arsenic of rice samples was determined after microwave digestion. The recoveries of 2 pretreatment methods were calculated by the sum of inorganic arsenic and organic arsenic, and the pretreatment methods were compared. The buffer salts such as ammonium dihydrogen phosphate, ammonium carbonate and diammonium hydrogen phosphate were selected and the pH value was optimized to confirm the optimum mobile phase conditions. Results In this method, 12.5 mmol/L diammonium hydrogen phosphate was used as the mobile phase, the mobile phase was adjusted to pH 8.5 and the flow rate was 1 mL/min. Under such conditions, 5 kinds of inorganic arsenic species could be separated completely. The results showed that the extraction efficiencies of the 2 pretreatment methods were higher than 87.5%, and the extraction efficiency of the acid-thermal assistant extraction method was higher. Conclusions The method is accurate, simple, which is suitable for the determination of inorganic arsenic in rice.