大气颗粒物滤膜中极性有机物在线衍生装置的设计与应用  

Design and application of online derivatization device for polar organics on atmospheric particulate filter

作　　者：张晗[1] 廖旭[1] 魏来 张子兴[1] 任红云 张娴[1] ZHANG Han;LIAO Xu;WEI Lai;ZHANG Zixing;REN Hongyun;ZHANG Xian(Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 China)

机构地区：[1]中国科学院城市环境研究所环境与健康重点实验室,福建厦门361021

出　　处：《色谱》2022年第1期100-106,共7页Chinese Journal of Chromatography

基　　金：厦门市科技项目(3502Z20182002);国家自然科学基金(21806161).

摘　　要：设计制作了一套用于气相色谱-质谱(GC-MS)分析极性有机物的在线衍生装置,并将其应用于大气颗粒物样品中极性有机物的检测。将大气颗粒物滤膜样品置于GC-MS进样口,通过使用套针组件,匀速引入气态衍生试剂N-甲基-N-(三甲基硅烷)三氟乙酰胺(MSTFA),使其在衬管内于310℃下与待测物接触,10 min即可完成硅烷化在线反应。反应过程中,色谱柱箱保持低温,衍生产物得以在柱头保留,反应完成后色谱柱箱程序升温,使衍生产物直接进行后续分离检测。应用在线衍生装置建立有机酸分析方法,获得了一元酸、二元酸、芳香酸、醇等极性有机物的检测信息,涵盖了大气化学分析常见的大部分目标化合物。该方法检出限为0.02~0.53 mg/L,线性相关系数为0.976~0.996,日内、日间RSD为0.27%~7.28%,适用于批量大气环境样品检测。与传统离线衍生技术相比,本装置使衍生反应处于高温惰性气体氛围,排除空气中水分对衍生试剂的损耗和衍生产物降解风险,反应稳定、效率高;固体滤膜上有机物进行热解吸的同时完成在线衍生,样品需求量小,操作简单,零有机试剂污染,并有望应用于醇类、酚类等多种极性有机化合物的分析。此外,该装置搭建简单,可模块化设计,适用于不同品牌气相色谱仪,具有商业化推广前景。An online derivatization device for the analysis of polar organic compounds by gas chromatography-mass spectrometry(GC-MS)is designed.The derivatization reaction occurs in the hot GC injection port,and this is also known as injection port derivatization(IPD).IPD is usually performed in two ways:1)direct IPD and 2)ion-pair extraction,followed by IPD.In both cases,the derivatization reagent reacts in liquid form.However,a method for online derivatization using gaseous derivatization reagents is provided.A special needle is designed and placed on the carrier gas transfer line to the injection port.The carrier gas is introduced into a glass bottle containing the derivative reagent(N-methyl-N-(trimethylsilyl)trifluoroacetamide,MSTFA),and then,the gaseous derivative reagent in the headspace is pressed out and introduced into the injection port of the GC instrument at a constant speed.The filter to be analyzed is placed directly in the liner,and the polar organic compounds on the filter react with gaseous MSTFA at 310℃for 10 min in the injection port.During derivatization,the column oven is maintained at room temperature,and all the derivatives stay on the column head.When the reaction is complete,the MSTFA supply is ceased.The oven temperature is programmed,and the solvent delay is set until the excessive MSTFA is removed.The derivatives are allowed to pass through the column and analyzed by the MS detector.To prevent a large number of derivative reagents from entering the column,the injection port is set in split mode with a split ratio of 5∶1.Variables such as the injection-port temperature and derivatization time are investigated.The GC-MS responses of the ten silylated derivatives increase with increasing injection-port temperature(290-310℃),indicating that high temperatures can enhance the silylation efficiency.The derivatization times were also investigated.The GC-MS responses increased with an increase in the reaction time from 0 to 10 min,while higher temperatures or longer reaction times lead to the loss

关 键 词：气相色谱 质谱 硅烷化反应 在线衍生 极性有机物 大气颗粒物 装置 

分 类 号：O658[理学—分析化学]