气相色谱三重四级杆串联质谱法测定雾霾PM2.5中12种共平面多氯联苯

Determination of 12 coplanar polychlorinated biphenyls of smog PM2.5 by gas chromatography tandem mass spectrometry

目的建立雾霾PM2.5中12种共平面多氯联苯的前处理及气相色谱三重四级杆串联质谱(gas chromatography tandem mass spectrometry,GC-MS/MS)分析方法。方法石家庄市采集的雾霾PM2.5颗粒物样品,用正己烷丙酮混合溶剂经加速溶剂萃取仪(accelerated solvent extraction,ASE)萃取,佛罗里硅土柱净化,氮吹后正己烷定容,气相色谱三重四级杆串联质谱多重反应监测(multiple reaction monitoring,MRM)模式测定,外标法定量。3倍信噪比确定检出限。结果 12种共平面多氯联苯在1~100μg/L范围内线性良好,相关系数R^2>0.999。该方法的仪器检出限为0.034~0.11μg/L,方法检出限为0.05~0.16 pg/m^3。3个水平的加标回收率为77.0%~110.2%,相对标准偏差(RSD)在2.8%~11.2%之间。结论净化步骤和优化的仪器参数使目标物能够准确地检测和定量,该方法简便快速、溶剂用量少、基质干扰少,对客观表达雾霾PM2.5中污染状态信息有重要意义,适用于雾霾PM2.5中痕量共平面多氯联苯的检测要求。

Objective An effective method for the trace extract and analysis of 12 coplanar polychlorinated biphenyls was devel- opment using gas chromatography tandem mass spectrometry（ GC - MS/MS）. Methods Air samples of PM2.5 were taken with air samplers equipped with a whatman glass fiber filter for collecting particle - bound PCBs compounds from Shijiazhuang Cit- y. Samples were extracted by accelerated solvent extraction with aceton and hexane and purified using florisil solid phase extrac- tion columns and the concentrations of extracts of coplanar polychlorinated biphenyls were quantified by gas chromatography tan- dem mass spectrometry under multiple reaction monitoring（MRM） mode by external standard means. The MRM scheme used in- volved transitions of the precursor ions to elected two product ions. The limits of detection were evaluated on the values of the low- er concentration fortified sample under the signal - to - noise ratio of 3： 1. Results 12 coplanar polychlorinated biphenyls showed a good linearity in the range of 1 - 100 μg/L with the correlation coefficients more than 0. 999. The detection limits of instrument and analytical method range of 0. 034 -0. 11 μg/L and 0. 05 -0. 16 pg/m3. The recoveries was applied for the samples spiked at three fortification levels range of 77.0% - 110. 2% with the precisions of 2. 8% - 11.2% RSD. Conclusion Intensive clean - up procedures in combination with optimized instrumental parameters provided reliable detection and quantification of these com- pounds. These results indicated that this method was simple, rapid, sensitive and was of great significance in terms of providing more objective information on contamination status of the analyzed samples. The method was suitable for the simultaneous determi- nation requirements of 12 coplanar polychlorinated biphenyls of smog PM2. 5.