大气气溶胶中重金属污染物能够对生态系统甚至人体造成不利影响, 因而对其中重金属污染物进行检测和分析是有必要的。利用激光诱导击穿光谱 (LIBS) 技术, 对持续收集 20 min 的大气 气溶胶进行金属元素的定性分析和有毒重金属的定量分析, 并重点研究了在本实验系统下气溶胶中 Cr 元素的 LIBS 分析谱线。 随后经归一化处理研究了大气气溶胶中 Cr 元素强度与中国环监总站公布的 PM2.5 和 PM10 含量之间的关系, 通过建立重金属元 素的定标曲线检测了气溶胶样品中重金属元素的含量, 并计算了相关重金属元素的检测限。实验结果表明, 大气气溶胶中含 有 Cr、Na、Mg、Al、Ca、Fe、Ba 等金属元素, 其中 Cr 元素谱线强度与中国环监总站公布的 PM2.5、PM10 数据成正相关, 尤其与 PM2.5 数据相关性更好。本实验建立的重金属元素定标曲线相关系数 R2 在 0.995～0.997 之间, 检测限在 1.9～3.6 mg/kg 之间, 表明该方法可以用于快速检测大气气溶胶中的重金属元素含量。

Heavy metal pollutants in atmospheric aerosols can adversely affect ecosystem and even human body. Therefore, it is necessary to detect and analyze the heavy metal pollutants in aerosols. Using laser-induced breakdown spectroscopy (LIBS), qualitative analysis of metallic elements and quantitative analysis of toxic heavy metals in atmospheric aerosol collected in 20 minutes were carried out, and LIBS analysis spectrum of Cr in aerosols under this experimental system was mainly studied. Then the relationship between the intensity of Cr in atmospheric aerosols and the contents of PM2.5 and PM10 published by China Environmental Monitoring Station was studied by normalization. Moreover, by establishing the calibration curve of heavy metal elements, the content of heavy metal elements in the aerosol samples was detected, and the corresponding detection limit was calculated. The experimental results show that atmospheric aerosols contain metal elements such as Cr, Na, Mg, Al, Ca, Fe, and Ba, and the intensity of the Cr element line is positively correlated with the PM2.5 and PM10 data published by China National Environmental Monitoring Centre, especially with the PM2.5 data. The correlation coefficient R2 of the calibration curve for heavy metal elements established in this experiment ranges from 0.995 to 0.997, and the detection limit ranges from 1.9 to 3.6 mg/kg, which indicates that the method can be applied for rapid detection of the content of heavy metal elements in atmospheric aerosol.