液相色谱-双通道原子荧光检测联用法同时测定砷和硒的形态

Simultaneous speciation of arsenic and selenium by high performance liquid chromatography-double channel atomic fluorescence spectrometry

建立了一种利用高效液相色谱-双通道原子荧光检测联用同时进行砷和硒形态分析的方法。以10mmol/LNH4H2PO4溶液（pH5.6）（添加2.5%（体积分数）的甲醇）为流动相,在12min内同时分离了三价砷（As（Ⅲ））、一甲基砷（MMA）、二甲基砷（DMA）、五价砷（As（Ⅴ））、硒代胱氨酸（SeCys）、硒代蛋氨酸（SeMet）和四价硒[Se（Ⅳ）]等化合物。As（Ⅲ）、DMA、MMA、As（Ⅴ）、SeCys、SeMet和Se（Ⅳ）的检出限分别为1,3,2,3,4,18和3μg/L（进样量为200μL）,5次测定的相对标准偏差为1.9%-6.1%（As100μg/L,Se300μg/L）。应用该方法对人体尿样及硒酵母片中砷和硒的形态进行了分析,目标物在尿样中的加标回收率为83%～108%,在硒酵母片中的加标回收率为88%～105%。实验结果表明,该方法可用于尿样及药品中砷和硒形态的日常分析。该方法减少了样品的分析时间和试剂用量,降低了工作强度,提高了工作效率。

A comprehensive method for simultaneously detecting species of arsenic and selenium including arsenite （As （Ⅲ））, monomethylarsonic acid （MMA）, dimethylarsinic acid （DMA） , arsenate （As （ Ⅴ ） ） , selenocystine （SeCys） , selenomethionine （SeMet） and selenate （Se （Ⅳ）） was developed with high performance liquid chromatography-hydride generationdouble channel atomic fluorescence spectrometry （HPLC-HG-AFS）. An anion-exchange column （PRP-X100） with eluent of 10 mmol/L NH, H2PO4 containing 2.5% （v/v） methanol was employed to separate these species within 12 min. The detection limits of As （ Ⅲ ）, DMA, MMA, As（ Ⅴ ）, SeCys, SeMet and Se（Ⅳ） were 1, 3, 2, 3, 4, 18 and 3 μg/L （200 μL of injection）, respectively. The relative standard deviations in five independent determinations varied from 1.9% to 6. 1% for arsenic and selenium species at the concentration levels of 100 and 300 μg/L. The proposed method was applied to analyze the selenium yeast tablet and human urine samples. The recoveries from spiked selenium yeast tablet and urine samples ranged from 88% to 105% and from 83% to 108%, respectively. The results showed that this method can be used for determining arsenic and selenium species in urinary metabolites and drug samples in daily analysis conveniently.