电子制冷预浓缩-双柱气相色谱-质谱/氢火焰检测器法测定空气中104种挥发性有机物  

Determination of 104 volatile organic compounds in air by double column gas chromatography-mass spectrometry/flame ionization detector coupled with electronically controlled cryo-focusing unit

作　　者：张烃[1] 张翼翔 杜祯宇 刀谞[2] 张秀蓝[1] 曹冠 贾岳清 杜世娟 汤卡 单丹滢 周昊[1] 周瑞[1] ZHANG Ting;ZHANG Yixiang;DU Zhenyu;DAO Xu;ZHANG Xiulan;CAO Guan;JIA Yueqing;DU Shijuan;TANG Ka;SHAN Danying;ZHOU Hao;ZHOU Rui(National Research Center for Environmental Analysis and Measurements (CNEAC),Beijing 100029,China;China National Environmental Monitoring Center (CNEMC),Beijing 100012,China;Beijing Branch,Shimadzu (China) Co. Ltd,Beijing 100020,China)

机构地区：[1]国家环境分析测试中心,北京100029 [2]中国环境监测总站,北京100012 [3]岛津企业管理(中国)有限公司北京分公司,北京100020

出　　处：《色谱》2019年第4期418-425,共8页Chinese Journal of Chromatography

基　　金：国家重点研发计划项目课题(2016YFC0206204)~~

摘　　要：基于吸附剂辅助电子制冷预浓缩技术,建立了多维切割双柱气相色谱-质谱/氢火焰离子化检测器(GC-MS/FID)同时测定环境空气中104种挥发性有机物(VOCs)的方法。将采集于苏玛罐中的环境空气样品在配有吸附剂的电子制冷预浓缩系统中富集、脱附、除水、除CO_2和浓缩,然后通过GC-MS/FID的多维切割单元将C_2～C_3组分和C_4～C_(12)组分分别引入PLOT柱和InterCap-624柱进行分离。C_2～C_3组分用FID检测,以保留时间定性、外标法定量;C_4～C_(12)组分采用电子轰击离子源质谱检测,以保留时间和特征离子定性、内标法定量。考察了冷阱吸附剂种类、辅助压力控制单元压力设置、双柱切换时间切割点等参数对分析结果的影响,优化了GC-MS/FID条件,并评估了在此优化条件下的方法性能。104种VOCs在0.044 6～0.892μmol/m^3范围内线性关系良好,相关系数(r)为0.998 4～0.999 9,对0.044 6μmol/m^3和0.223μmol/m^3水平的混合标准气体重复6次进样,平均回收率为86.4%～116.1%,相对标准偏差为0.9%～11.3%;方法的检出限为0.145～1.90μg/m^3,定量限为0.435～5.70μg/m^3。该法稳定性好,灵敏度高,操作简便,可用于环境空气中104种VOCs的测定。A method for the determination of 104 volatile organic compounds (VOCs) in ambient air based on double column multi dean switching gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID) coupled with sorbent assisted electronically controlled cryo-focusing unit was developed and evaluated. The sorbent assisted electronically controlled cryo-focusing unit was used for trapping, dehydration and focusing of VOCs sampled in summa canisters. The VOCs were split into two parts by the multi dean switching unit in GC-MS/FID. The C 2-C 3 components were determined in a PLOT capillary column with an FID detector, while the C 4-C 12 components were determined in an Intercap-624 capillary column with a MS detector . The C 2-C 3 components were qualitatively confirmed from the retention time and quantified by the calibration curves, while the C 4-C 12 components were qualitatively confirmed from the retention time and the relative abundance ratio of characteristic ions, and quantified by the internal standard calibration curves. The major factors influencing the cryo-focusing performance including the type of sorbent tube, the pressure employed in assisted pressure control unit (APC), and the split point in multi dean switching unit were investigated. The chromatographic and MS parameters were optimized. Under optimum conditions, a linear relationship was observed with the content of VOCs ranging from 0.044 6 to 0.892 μ mol/m^3 , and correlation coefficients ( r ) no less than 0.998 4 . The average spiked recoveries of the six VOCs at two levels of 0.044 6 μ mol/m^3 and 0.223 μ mol/m^3 were 86.4%-116.1%, with relative standard deviations in the range of 0.9%-11.3% The method detection limits (MDLs) and the limits of quantification (LOQs) were 0.145-1.90 μ g/m^3 and 0.435-5.70 μ g/m^3 , respectively. The method is accurate, sensitive and simple, and is suitable for the determination of the 104 VOCs in ambient air.

关 键 词：双柱气相色谱-质谱/氢火焰检测器 电子制冷预浓缩 多维切割单元 挥发性有机物 环境空气 

分 类 号：O658[理学—分析化学]