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.