集束毛细管柱富集便携式光电离飞行时间质谱检测大气中苯系物  

Determination of Benzenes in Atmosphere by Multi-capillary Column Enrichment Portable Photoionization TOF-MS

作　　者：刘聪 李杨[2] 蒋吉春 李金旭[2] 杨明 王祯鑫[2] 花磊[2] 张晓辉[1] 李海洋[2] LIU Cong;LI Yang;JIANG Ji-chun;LI Jin-xu;YANG Ming;WANG Zhen-xin;HUA Lei;ZHANG Xiao-hui;LI Hai-yang(College of Environment and Chemical Engineering,Dalian University,Dalian 116622,China;Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China)

机构地区：[1]大连大学环境与化学工程学院,辽宁大连116622 [2]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《质谱学报》2023年第2期233-241,共9页Journal of Chinese Mass Spectrometry Society

基　　金：国家自然科学基金(22027804,22174142);大连化学物理研究所创新研究基金(DICP I202144,DICP I202123)。

摘　　要：本研究利用集束毛细管柱研制了一种新型富集进样装置,并与便携式光电离飞行时间质谱(PI-TOF-MS)联用,实现了环境空气中苯系物的高灵敏检测。该富集进样装置无需制冷即可高效吸附苯系物,经过条件优化,样品经500 mL/min流速采样4 min,以2 mL/min载气流速进样3 min,捕集阱降温3 min,即可完成样品分析。与直接进样相比,富集进样后,苯、甲苯和对二甲苯的信号强度分别提高了130、220和255倍,相关系数(R^(2))均大于0.99,检出限分别达到0.23、0.19和0.23μg/m^(3),平行检测7个周期的相对标准偏差(RSD)小于6%。将研制的集束毛细管柱富集进样-便携式PI-TOF-MS应用于实际环境空气检测,结果表明,该仪器能够满足大气中痕量苯系物的检测需求,在现场环境快速检测领域具有广阔的应用前景。Benzenes of wide sources can cause serious air pollution.In this study,a novel enrichment sampling device based on multi-capillary column was developed and coupled to portable photoionization time-of-flight mass spectrometer(PI-TOF-MS)to highly and sensitively detect benzenes in ambient air.The enrichment sampling device was composed of seven identical HP-PLOT Q capillary columns(0.10 m×0.53 mm×40μm)coated with polystyrene-divinylbenzene,which could achieve efficient adsorption of benzenes at room temperature.The homebuilt portable PI-TOF-MS has a volume of(0.47×0.35×0.38)m^(3),a weight of 35 kg,and a resolution of better than 1000(full width at half-maximum,FWHM)at m/z 92.Benzene,toluene and p-xylene gas diluted by nitrogen were used to optimize the operating parameters of the whole system.The optimal sampling flow rate was selected as 500 mL/min,the enrichment time was 4 min,the thermal desorption temperature was 160℃,and the analytical time for single sample was less than 10 min.Compared with direct sampling,the signal intensities of benzene,toluene and p-xylene were enhanced by 130,220 and 255 folds under the optimal conditions,respectively.The linearity,limit of quantitation(LOQ)and stability of the system were evaluated.As a result,the linear concentration range of 6.96-1741.05μg/m^(3)for benzene,8.21-2053.55μg/m^(3)for toluene,and 9.46-2366.05μg/m^(3)for p-xylene were obtained with the correlation coefficients(R^(2))of 0.9938,0.9997 and 0.9991,respectively.The limits of quantification(LOQs,S/N=10)were 0.78,0.63 and 0.76μg/m^(3),respectively.The relative standard deviations of the signal strengths for the three compounds were less than 6%during seven analytical cycles.Finally,the developed multi-capillary column enrichment portable PI-TOF-MS was used for comparative analysis of indoor and outdoor air in the laboratory.As a consequence,toluene and p-xylene were detected in both indoor and outdoor air of the laboratory.The indoor concentrations of the two compounds were 2.6 and 23.3μg/m^(3),respec

关 键 词：集束毛细管柱 富集 光电离 便携式飞行时间质谱(PI-TOF-MS) 苯系物 

分 类 号：O657.63[理学—分析化学]