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目的建立有机溶剂萃取-氢化物原子荧光光谱法测定食品中的总无机砷含量的方法。方法利用8 mol/L盐酸浸泡样品,使样品中的无机砷以氯化物的形式提取出来,加入还原剂使五价砷还原为三价砷,用乙酸丁酯萃取样液,再以稀盐酸反萃取,氢化物发生原子荧光法检测总无机砷。结果通过对比不同萃取与反萃取体系以及不同的分离条件对结果的影响,推荐在8 mol/L盐酸条件下采用乙酸丁酯-3%稀盐酸萃取-反萃取体系。该方法的线性范围为0～100μg/L,相关系数为>0.999 0。在最佳条件下,对20份试剂空白溶液进行测定,方法检出限为0.9μg/L。采用该方法对实际样品进行加标回收试验,回收率为84.4%～105.0%,精密度(RSD)为1.3%～4.5%。结论该方法操作简便,测定结果准确度和精密度较好,且实验成本低、操作简单,适合在基层实验室中推广。
Objective To establish a method for the determination of total inorganic arsenic in food by organic solvent extraction - hydride generation atomic fluorescence spectrometry. Methods The samples were immersed in 8 mol / L hydrochloric acid to extract the inorganic arsenic in the form of chloride. The reducing agent was added to reduce pentavalent arsenic to trivalent arsenic. The sample was extracted with butyl acetate, Extraction, Hydride Generation Atomic Fluorescence Detection of Total Inorganic Arsenic. The results by comparing different extraction and stripping system and different separation conditions on the results, the recommended 8 mol / L hydrochloric acid conditions using butyl acetate -3% dilute hydrochloric acid extraction - stripping system. The linear range of this method is 0 ~ 100μg / L, the correlation coefficient is> 0.999 0. Under the optimal conditions, 20 reagent blank solution was determined, the detection limit was 0.9μg / L. The spiked recoveries of the samples were 84.4% ~ 105.0% and the precision (RSD) was 1.3% ~ 4.5%. Conclusion The method is simple and easy to operate, the results of the determination of the accuracy and precision better, and the experimental cost is low, simple operation, suitable for promotion in grassroots laboratories.