超级微波消解-电感耦合等离子体质谱法测定PM2.5滤膜中6种痕量重金属

Determination of 6 trace heavy metals in PM2.5 by Ultra WAVE digestion-inductively coupled plasma mass spectrometry

目的建立超级微波消解—电感耦合等离子体质谱法同时测定PM2.5滤膜中6种痕量重金属元素(Cr、Ni、Cu、As、Cd和Pb)的测定方法。方法利用Ultra WAVE超级微波消解平台,以HNO_3+H_2O_2为消解体系,对PM2.5滤膜样品进行消解预处理,利用电感耦合等离子体—质谱仪同时测定6种痕量重金属元素。结果各元素标准曲线的相关系数均大于0.999 8,方法的检出限、灵敏度和精密度均符合分析测定的需求;当采样体积为144 m^3时,最低检测浓度(LOQ)分别为0.97 ng/m^3、1.16 ng/m^3、0.83 ng/m^3、1.34 ng/m^3、1.85 ng/m^3和3.56 ng/m^3;对标准参考物质GBW(E)080212进行测定,结果值均在参考值允许范围内,各元素的加标回收率均在83.69%~97.67%,标准偏差(RSD%)均小于5%。结论该方法具有样品前处理操作简便、检出限低、精密度高、准确性好等优点,适用于PM2.5中6种痕量重金属元素的快速、准确定量分析。

Objective To establish a method for simultaneous determination of six heavy metals（Cr, Ni, Cu, As, Cd and Pb） in PM2.5 by Ultra WAVE digestion-inductively coupled plasma mass spectrometry（ICP-MS）. Methods The PM2.5samples were digested in HNO_3＋H_2O_2using Ultra WAVE, then the concentration of six trace heavy metals in the leach solution were determined by ICP-MS. Results The correlation coefficient of six heavy metals＇ standard curves was more than0.999 8. The detection limits（LOQ）, the sensitivity and precision were up to the requirements. When sample volume was 144 m^3,the LOQ for Cr, Ni, Cu, As, Cd and Pb were 0.97 ng/m^3, 1.16 ng/m^3, 0.83 ng/m^3, 1.34 ng/m^3, 1.85 ng/m^3 and 3.56 ng/m^3, respectively. The recovery rates of the method for all six elements were within the range of 83.69%-97.67%, with the relative standard deviations less than 5%. Conclusions The results showed the method is accurate, convenient and efficient, with low detection limit, and it can be used for the detection of 6 six trace heavy metals in PM2.5.