不连续进样方式ICP-MS法测定尿砷的两种方法比较

Comparison of two methods for determination of urinary arsenic by ICP-MS with discontinuous injection

目的应用电感耦合等离子体质谱(ICP-MS)的智能集成一体化进样系统(ISIS3)不连续进样与碰撞模式结合,探索标准曲线法和标准加入法对尿砷测定结果的影响。方法尿样经1%HNO3稀释10倍,在线引入内标锗,采用ICP-MS的标准曲线法和标准加入法分别对尿砷进行定量分析。结果在1~600μg/L(以尿样10倍稀释计)范围内,标准曲线法相关系数>0.999,检出限为0.26μg/L,定量下限为0.88μg/L,加标回收率为101.0%~102.4%,相对标准偏差为0.7%~1.2%;标准加入法相关系数>0.999,检出限为0.13μg/L,定量下限为0.42μg/L,加标回收率为100.0%~100.6%,相对标准偏差为0.8%~1.6%。结论2种方法都具有操作快捷、简单、灵敏、高精密度等优点,两者检测结果准确可靠,具有很好的一致性,均适合大批量的尿砷快速检测。

Objective To explore the impact of standard curve method and standard addition method on the determination results of urine arsenic by applying combination of collision mode and discontinuous injection from intelligent integrated sample injection system(ISIS3)of inductively coupled plasma mass spectrometry(ICP-MS).Methods The urine sample was diluted 10 times with 1%HNO3,while the internal standard germanium was introduced online.The urinary arsenic was quantitatively analyzed by ICPMS standard curve method and standard addition method.Results When the concentration range was 1-600μg/L(calculated by diluting urine sample 10 times),the results of standard curve method showed that the correlation coefficient(r)was>0.999,the detection limit was 0.26μg/L,the lower limit of quantification was 0.88μg/L,the recoveries were 101.0%-102.4%,and the relative standard deviations(RSD)were 0.7%-1.2%.The results of standard addition method showed that r was>0.999,the detection limit was 0.13μg/L,the lower limit of quantification was 0.42μg/L,the recoveries were 100.0%-100.6%,and the RSDs were 0.8%-1.6%.Conclusion Two methods have the advantages of convenient for operation,high sensitivity and precision.The results of them are accurate and reliable,and have good consistency.Both are suitable for the rapid detection of urine arsenic with multitudinous samples.