大气PM_(2.5)中16种多环芳烃的聚焦微波辅助萃取-气相色谱质谱联用快速测定法

Rapid determination of sixteen polycyclic aromatic hydrocarbons in PM2.5 by focused microwave-assisted extraction-gas chromatography-mass spectrometry

目的建立大气PM_(2.5)中16种多环芳烃的聚焦微波辅助萃取-气相色谱质谱联用(FMAE-GC-MS)快速测定法。方法切取已采集大气PM_(2.5)样品的1/8玻璃纤维滤纸,剪碎后置于微波萃取罐中,以正己烷-丙酮溶液(体积比为9∶1)65℃恒温微波萃取20 min,减压浓缩后氮吹近干,用正己烷定容至1.0 ml,以GC-MS法测定萘、苊烯、苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、茚并(1,2,3-cd)芘、二苯并(a,h)蒽、苯并(g,h,i)苝。以保留时间和特征碎片离子定性,标准曲线法定量。结果该方法在0.5~10μg/ml范围内有良好线性关系,相关系数为0.995 8~0.999 5。在选择离子扫描模式下,检出限为0.06~0.11μg/ml,空气中最低检出浓度为0.42~0.77 ng/m3(以采集144 m^3空气计),相对标准偏差(RSD)为6.3%~15.2%。对四川某地冬、春季雾霾天30份大气PM_(2.5)样品中的16种多环芳烃进行测定,发现高沸点PAHs检出率较高,苯并(g,h,i)苝最高含量达到23.2 ng/m^3,16种PAHs检出率为26.7%~100%,合计浓度为99.1 ng/m^3。结论该方法快速、环保、提取效率高、定性定量准确、自动化程度高、抗干扰能力强,适合大气PM_(2.5)批量样品中16种PAHs的同时测定。

Objective To establish a method for the determination of 16 PAHs including naphthalene, acenaphthylene,acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene,pyrene,benzo（a） anthracene, chrysene, benzo（b） fluoranthene,benzo（k）fluoranthene, benzo（a）pyrene, indeno（1, 2, 3-cd） pyrene, dibenzo（a,h）anthracene and benzo（g, h, i） perylene in PM2.5 by focused microwave-assisted extraction-gas chromatography-mass spectrometry（FMAE-GC-MS）. Methodes One eighth of the sampled glass fiber filter paper was cut into pieces and microwave extracted with n-hexane-acetone（V∶V=9∶1） at 65 ℃ for20 min; The resulting solution was concentrated under reduced pressure and blown to near dryness under gentle nitrogen flow,then the residue was redissolved in 1.0 ml n-hexane and the resulting solution was separated and analyzed by GC-MS. The analytes were identified by retention time and characteristic fragment ions and quantified by standard curve method. Results For FMAE-GC-MS, good linearity was obtained over the range of 0.5-10 μg/ml, and the correlation coefficients were 0.995 8-0.999 5. Under the SIM mode, the limits of detection were 0.06-0.11 μg/ml, the minimum detectable contents were 0.42-0.77 ng/m^3 in air（the sampled volume of air was 144 m^3）, the RSDs were 6.3%-15.2%. A total of 16 PAHs in 30 atmosphere PM2.5 samples collected on smoggy days in winter and spring in a region in Sichuan province were determined, and it was found that the detection rates of PAHs with high boiling points were high, and the maximum concentration of benzo（g, h, i） perylene reached 23.2 ng/m^3. The detection rates of the 16 PAHs were 26.7%-100%, and the average concentration was 99.1 ng/m^3.Conclusion The established method for simultaneous determination of 16 PAHs in PM2.5 has the characteristics of high extraction efficiency, accurate qualitation and quantitation, high automation degree and strong anti-interference capacity and is rapid, environment-friendly and suitable for batch analysis of air samples.