智能石墨消解–ICP–MS法测定空气PM2.5中的Pb和Cd

建立电感耦合等离子体质谱(ICP–MS)测定空气PM2.5中的Pb和Cd元素的分析方法。采用连续β射线–DHS PM2.5大气颗粒物浓度监测仪采集空气中的PM2.5,以智能石墨消解PM2.5滤膜样品,ICP–MS测定其中的Pb和Cd元素含量。在优化的仪器条件下,元素Pb和Cd标准曲线的线性相关系数均为0.999 9,检出限分别为0.018,0.52ng/m3,满足HJ 657–2013的要求。Pb和Cd的加标回收率分别为95.8%~101.4%,99.3%~104.9%,测定结果的相对标准偏差分别为4.20%和2.38%(n=6)。对滤膜标准样品进行了测定,测定结果与标准值一致。该方法测定结果准确、可靠,可用于测定空气PM2.5中的Pb和Cd。

Determination of Pb and Cd in Air PM2.5 by Intelligent Graphite Digestion and ICP-MS

The method for determination of Pb and Cd in air PM2.5 by inductively coupled plasma mass spectromenty(ICP-MS) was established. The PM2.5 in the air was automatically collected by using atmospheric particulate matter monitor and digested with intelligent graphite digestio, then the content of Pb and Cd was determined by ICP-MS. Under the optimal conditions, the linear correlation coefficients of Pb and Cd standard curve were 0.999 9. The detection limit of Cd, Pb was 0.018, 0.52 ng/m3, respectively, which meet the standard requirements of HJ 657-2013. The relative standard deviations of Pb and Cd determination results were 4.20%, 2.38%(n=6), respectively. The recoveries of Pb and Cd were 95.8%-101.4%,99.3%-104.9%, respectively. The filter membrane standard samples were determined by the method, the determination results were consistent with the standard values. The method is accurate and reliable, it can be used to determine Pb and Cd in PM2.5 of the air.