高效液相色谱-原子荧光光谱法测定人尿中6种形态砷

Determining 6 arsenic species in human urine by high performance liquid chromatography-atomic fluorescence spectrometry

目的建立高效液相色谱-原子荧光光谱(HPLC-AFS)法测定人尿中亚砷酸盐、二甲基砷酸、一甲基砷酸、二甲基亚砷酸、一甲基亚砷酸和砷酸盐等6种形态砷的方法。方法采用PRP-X100阴离子交换色谱柱,以浓度均为4.0 mmol/的碳酸铵、磷酸铵、硫酸铵混合液(体积比为1∶1∶1,pH值为8.9)为流动相,体积分数为10.0%的盐酸为载流,质量分数为3.5%的硼氢化钾为还原剂。尿样经离心分离后,采用HPLC-AFS仪检测尿液中6种形态砷。结果本方法测定6种形态砷的线性范围为3.90~100.00μg/L,相关系数为0.9991~0.9999,检出限为1.31~3.90μg/L;加标回收率为91.2%~103.5%,批内相对标准偏差(RSD)为0.5%~4.9%,批间RSD为1.8%~5.0%。样品在-80℃至少可以保存7 d。结论本方法检出限低、精密度好、灵敏度高,适用于人尿中形态砷的测定。

Objective To establish a methodology using high performance liquid chromatography-atomic fluorescence spectrometry(HPLC-AFS)for the determination of 6 arsenic species including arsenite,dimethyl arsenic acid,monomethyl arsenic acid,dimethyl arsenic acid,monomethyl arsenic acid and arsenite in human urine.Methods The PRP-X100 anion exchange chromatographic column was used with 4.0 mmol/L ammonium carbonate,ammonium sulfate and ammonium phosphate mixed solution with pH 8.9 as mobile phase.The carrier current was hydrochloric acid with volume fraction of 10.0%and reducing agent was potassium borohydride with mass fraction of 3.5%.After centrifugal separation of urine sample,6 forms of arsenics were detected by HPLC-AFS.Results The linear range of 6 forms of arsenics in urine was 3.90-100.00μg/L.The correlation coefficient was 0.9991-0.9999,and the detection limit was 1.31-3.90μg/L.The recovery rate was 91.2%-103.5%.The within-run and between-run relative standard deviations were 0.5%-4.9%and 1.8%-5.0%,respectively.The samples could be stored for at least 7 days under the temperature of-80℃.Conclusion The method has low detection limit,good precision and high sensitivity,which is suitable for the determination of arsenics in human urine.