常州市春季大气PM2.5中金属元素的分析及污染特征

建立了微波消解-电感耦合等离子体质谱(ICP-MS)法,同时测定大气PM2.5中K、Na、Ca、Mg、Fe、Al、Zn、Si、Ti、V、Cr、Mn、Co、Ni、Cu、As、Cd和Pb等18种金属元素的分析方法。样品用HNO3+H2O2(5:1)经微波消解系统进行前处理。该方法操作方便,酸用量少,由于是密闭消解,对环境污染也少。经过反复调试,确定了仪器最佳操作条件。结果表明,各种元素标准曲线的线性相关系数均在0.9990以上,方法检出限在0.07 μg/L~1.16 mg/L之间,精密度实验中各元素的RSD均小于7.53%,回收率在91.38%~117.53%之间。该方法能够快速有效地实现多元素同时测定,检测线性范围宽,测试结果准确可靠,可以应用于大气颗粒物中多种金属元素的测定。采用富集因子分析法对常州市大气中PM2.5做来源分析表明,常州市大气PM2.5中,大部元素的富集因子都大于10,其中,Ni、Cu、Zn、As、Cd、Co和Pb在各个采样点的富集因子都非常高,表明主要来自于人为污染。

Analysis and pollution characteristics of metal elements in PM2.5 in Changzhou during spring

Microwave digestion and ICP-MS method used for analyzing the 18 elements in PM2.5 of K, Na, Ca, Mg, Fe, Al, Zn, Si, Ti, V, Cr, Mn, Co, Ni, Cu, As, Cd and Pb simultaneously was established.The sample was dissolved by microwave digestion with HNO3+H2O2(5:1).The operation was convenient and the consume of acid was less than usual.Environmental pollution was not so heavy due to the microwave digestion was operated in airtight environment.The suitable instrumentation condition was determined.The results show that the linear correlation R≥0.9990, detection limit ranges from 0.07 μg/L~1.16 mg/L.The recovery for the elements determined was in the range of 91.38%~117.53% and the RSD≤7.53 was achieved.This method can simultaneously determine multiple elements with wide linear range and reliable result and it can be used for determining metal elements in atmospheric particulate matters.The result of enrichment factor indicated that the elements (as if Ni, Cu, Zn, As, Cd, Co and Pb) were enriched relative to their natural abundance in the crust soil and also suggested that these elements were related to anthropogenic behavior.