液相色谱-原子荧光光谱法测定稻米中的4种砷形态

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

采用液相色谱-原子荧光光谱法(LC-AFS)对稻米中的亚砷酸盐、二甲基砷、一甲基砷和砷酸盐4种砷形态进行测定,针对该方法中砷酸盐检测灵敏度较低的问题,通过优化前处理方法,结合CNWSep AX阴离子交换色谱柱(250mm×4.0mm,10μm)对4种砷形态进行分离和检测。结果表明:4种砷形态在5.0-100.0ng/mL范围内线性良好,相关系数均在0.999以上,检出限分别为0.238、0.350、0.290和0.636ng/mL,加标回收率在87.0%~104%之间,相对标准偏差均小于5%。该方法准确、高效、环保,适用于稻米样品中4种砷形态的定量分析。

A method was used for simultaneous determination of arsenious acid,dimethylasinic acid,monomethylarsonic aci,arsenic acid in rice by liquid chromatography-atomic fluorescence spectrometry.In order to solve the problem of low sensitivity of arsenic acidby optimizing the pre-processing method,and four arsenic species in rice sample were separated and detected by CNWSep AX HPLC Colμmn(250mm×4.0mm,10μm)The experimental results showed that the good lin?ear ranges of the four arsenic forms were obtained ranging from 5ng/mL to 100 ng/mL(R>0.999).The limits of detection for the four arsenic species were 0.238、0.350、0.290和0.636ng/mL.The spiked recoveries of the four arsenic species were in the range of 87.0%to 104%,and the relative standard deviations were less than 5%.The method was accurate,high efficien?cy and environmental for the determination of arsenic species in rice.