微波消解ICP-MS法测定寒水石二十一味散重金属含量

Content Determination of Heavy Metal Elements in Hanshuishi Ershiyiwei Powder by Microwave ICP-MS

目的建立测定寒水石二十一味散中的铅(Pb)、镉(Cd)、砷(As)、汞(Hg)、铜(Cu)元素含量的微波消解电感耦合等离子体-质谱法(ICP-MS)法。方法样品经微波消解,以锗(Ge)、铟(In)、铋(Bi)为内标元素,采用ICP-MS法同时测定5种元素。微波消解程序,消解功率为1 500 W;20 min升至120℃,保持5 min,再以5℃/min的速率升至140℃,保持15 min。ICP-MS设置条件,射频功率为1 100 W;检测器电压为-12. 25 V;模拟电压为-1 600 V,脉冲电压为800 V;载气为氩气,流速为15. 0 L/min;辅助气流量为1. 2 L/min;雾化器流量为0. 92 L/min;碰撞气为氦气,流量为3. 0 m L/min,雾化室温度为2℃;蠕动泵转速为36 r/min;数据采样模式为跳锋采集模式,数据重复采样次数为3次。结果 5种元素质量浓度均在0~100 ng/m L范围内与参比峰响应值线性关系良好(r> 0. 997),平均回收率为87. 90%~97. 63%,RSD为1. 52%~2. 35%;5种金属元素检出限均为0. 004 4~0. 055 1 ng/m L。结论该方法准确、稳定且无干扰,可用于寒水石二十一味散中5种重金属的含量测定。

Objective To establish a microwave ICP-MS method for the content determination of heavy metal elements Pb,Cd,As,Hg,Cu in Hanshuishi Ershiyiwei Powder. Methods The sample was digested with microwave digestion system,and the 5 elements of was simultaneously determined by ICP-MS method with Ge,In,Bi as the internal standard elements. Microwave digestion procedure: the digestion power 1 500 W;temperature increased to 120 ℃ in 20 min,kept for 5 min,and then raised to 140 ℃ at a rate of 5 ℃/min,kept for 15 min. ICP-MS setting conditions: RF power 1 100 W;detector voltage-12. 25 V;analogue voltage-1 600 V and the pulse voltage 800 V;the carrier gas was argon and the flow rate was 15. 0 L/min;the auxiliary air flow was 1. 2 L/min;nebulizer flow was 0. 92 L/min;the collision gas was helium and the flow rate was 3. 0 m L/min,the temperature of the atomizing chamber was 2 ℃;the speed of the peristaltic pump was 36 r/min;the data sampling mode was the peak-jumping mode,and the data was repeatedly sampled for 3 times. Results The mass concentration of the 5 elements had good linear relationship with the reference peak in the range of 0-100 ng/m L( r > 0. 997),and the average recoveries were 87. 90%-97. 63%,the RSDs were 1. 52%-2. 35%;the detection limit of the 5 metal elements was 0. 004 4-0. 055 1 ng/m L. Conclusion The method is accurate and stable without interference,which can be used for the content determination of the 5 heavy metal elements in Hanshuishi Ershiyiwei Powder.