应用电感耦合等离子体质谱研究硅灰中的重金属元素

Application of inductively coupled plasma mass spectrometry to determine heavy elements in silica fume

建立八极杆碰撞/反应池电感耦合等离子体质谱（ORS-ICP-MS）法测定硅灰中Cr,Ni,As,Cd,Sb和Pb等重金属元素的分析方法。样品经硝酸＋氢氟酸密闭微波溶解后,采用ORS-ICP-MS法测定上述6种重金属元素。应用ORS技术消除高盐基体对待测元素产生的多原子离子质谱干扰,研究不同碰撞气流速对待测元素预估检测限（EDL）的影响,采用基体匹配并以Rh为内标元素校正质谱分析中基体效应并补偿了信号漂移。在选定的条件下,样品的加标回收率为92.0%-106.0%,相对标准偏差（RSD）均小于3.4%,各待测元素的检出限为12.8-31.5ng/L。

A method for simultaneous and quantitative determination of Cr, Ni, As, Cd, Sb and Pb in silica fume by octopole reaction system inductively coupled plasma mass spectrometry（ORS-ICP-MS） was established. The sample was digested by HNO3＋HF with microwave digestion followed by dilution with ultrapure water and then the above six heavy metal elements in the solution were analyzed directly by ICP-MS. Using ORS, the polyatomic interferences caused by the high salty matrixes were eliminated. The effect of the He collision gas flow rate on the estimated detection limits of Cr,Ni, As and Cd was investigated. The matrix effect was minimized through matrix matching, and Rh was used as internal standard element. Under the optimal condition, the recovery of standard addition is 92.0%-106.0%, and the relative standard deviation（RSD） is less than 3.4%. The detection limits is 12.8-31.5 ng/L.