ICP-MS法测定南京市环境空气PM_(2.5)中多种元素

Elements in PM_(2.5) in Nanjing by ICP-MS Determination

采用聚四氟乙烯膜采样,硝酸-过氧化氢-氢氟酸微波消解样品,ICP-MS法测定南京某国控点环境空气PM_(2.5)中30种元素,结果目标元素在0μg/L^500μg/L之间线性良好,方法检出限为0.02 ng/m^3~15 ng/m^3,实际样品6次测定结果的RSD为0.5%~19.6%,加标回收率为78.5%~126%;所测元素的年日均值为0.03 ng/m^3~1 462 ng/m^3,占PM_(2.5)总量的7.3%。主要来自化石燃烧、机动车排放和钢铁冶炼的Cd、Zn、Se、Pb、Sb、Cu、As富集程度较高,Al、Ba、Be、Fe主要来自土壤岩石等自然源,富集度低。元素测定值季节分布呈秋冬高、春夏低的态势,与PM_(2.5)的季节变化趋势一致。

In this paper, 30 elements in ambient PM2.5 in Nanjing were collected by Teflon filter, digested by microwave and nitric acid-hydrogen peroxide-hydrofluoric acid, determined by ICP-MS. Some measurement parameters were obtained from method study. The elements had good linearity range in 0 μg/L -500 μg/L. Of all the elements,the MDL were 0.02 ng/m3 -15 ng/m3,the RSD were 0.5% -19.6%（n =6） and the recov-eries ranged in 78. 5% -126% . Results from practical sample showed that the annual mean concentration of the detected elements were in 0.03 ng/m3 -1 462 ng/m3,accounting for 7. 3% of PM2.5 total mass. As, exceeding the national standard, could be a threat to public health. Cd, Zn, Se, Pb, Cu and As from fossil- fuel, vehicle exhausting and steelmaking had large enrichment factor. Al, Ba, Be and Fe came from natural sources such as soil and rock for their low enrichment. The concentration of most elements were higher in autumn and winter than that of in spring and summer, in accordance with the seasonal variation of PM2.5.