液相色谱—原子荧光联用法测定大米中无机砷含量

Determination of arsenic in rice by liquid chromatography-atomic fluorescence spectrometry

采用液相色谱—原子荧光联用法测定大米中无机砷含量。根据GB5009.11—2014标准,研究不同提取剂对大米中无机砷提取率的影响,对试样大米进行了加标回收、重复性实验。结果表明:提取剂为0.15 mol/L硝酸溶液,提取率可达到90%以上,回收率As(Ⅲ)在97%~103%,As(Ⅴ)在91%~100%。相对标准偏差(n=6)As(Ⅲ)和As(Ⅴ)均小于5%。方法的检出限:As(Ⅲ)为0.607 ng/m L,As(Ⅴ)为1.021 ng/m L。该方法适合测定大米中无机砷含量。

In this study,we determined the arsenic content in rice by using liquid chromatography-atomic fluorescence spectrometry.Referring to national standard GB 5009.11—2014,we studied the influence of different extraction agents on the extraction rate of arsenic from rice,and carried out recovery and repetition tests.The results showed that,when using 0.15 mol/L nitric acid solution as extraction agent,the extraction rate reached up to90 %,the recovery rate of As（III） and As（V） was 97 % ～ 103 % and 91 % ～ 100 % respectively,and the relative standard deviation（n = 6） of As（III） and As（V） was less than 5 %.The detection limit of As（III） was 0.607 ng/m L,and that of As（V） was 1.021 ng/m L.Such method was suitable for the determination of arsenic content in rice.