ICP-MS测定西藏热泉水中总砷

Determination of arsenic in tibet spring waters by inductively coupled plasmamass spectrometry

西藏地区热泉水矿化度较高,不同类型热泉水砷含量差异大。为快速准确测定其中砷的含量,建立了碰撞模式-电感耦合等离子体质谱测定热泉水中总砷的方法。研究了样品保存条件、样品稀释倍数、KED气流量等条件对测定结果的影响。通过优化仪器的工作条件、样品稀释等方法,消除了低分压和高矿化度的影响,运用碰撞池技术,有效消除^(40)Ar^(35)Cl^(+)、^(40)Ca^(35)Cl^(+)、^(39)K^(36)Ar^(+)对砷的干扰。在样品中加入乙醇溶液,提高砷的灵敏度。结果表明:砷的检出限(3s)为0.22μg·L^(-1),加标回收率在91.01%~108.96%之间,测定值的相对标准偏差(n=6)为2.2~4.5%,方法可以快速、准确测定西藏热泉水中总砷。

The mineralization extent of hot spring water in Tibet is relatively high,the arsenic contents among hot spring waters were vastly different.In order to quickly and accurately determine the content of arsenic in different hot spring waters,a method for the determination of Arsenic in hot spring waters by KED collision mode inductively coupled plasma mass spectrometry(ICP-MS)was established.The effects of sample storing condition,sample dilution multiple,KED gas flow and other parameters on the determina-tion results are reanalyze.By optimizing the working conditions of the instrument,sample dilution,the influences of low pressure and hyper-salinity are eliminated.The interference of^(40)Ar^(35)Cl^(+),^(40)Ca^(35)Cl^(+),^(39)K^(36)Ar^(+)to arsenic was reduced by using collision cell tech-nique.Sensitivity of arsenic was raised by adding ethanolic solution.As shown by the results,the method has a detection limit of 0.22μg·L^(-1),recoveries of 91.01%~108.96%by standard addition,and relative standard deviation(n=6)of 2.2%~4.5%.This method can be used for the rapid and accurate determination of arsenic in Tibet hot spring waters.