摘要
用包覆聚二甲基硅氧烷(PDMS)吸附层的搅拌子作被动大气采样器,建立了搅拌子吸附-热脱附-气相色谱-质谱法(SBSE-TD-GC-MS)分析大气中多氯联苯(PCBs)的方法。优化后的热脱附温度为280℃,热脱附时间为6 min,聚焦冷阱的温度为-40℃,33种PCB单体的热脱附残留比例低于7%。验证了方法的线性、精密度和重复性。标准曲线5个点线性关系良好,33种PCB单体的相关系数r>0.998。方法精密度验证的相对标准偏差(RSD)为0.79%~20.2%(n=8),日内重复性实验的RSD为0.43%~29.8%(n=10),日间重复性实验的RSD为3.20%~29.6%(n=20),方法检出限(LOD)为0.01~2.51 pg,回收率为98%±18%。将建立的方法用于北京大气中PCBs的分析。检出8种PCB单体,质量为2.94~129 pg。在32 d的采样周期内PCB-52、PCB-123、PCB-155一直处于线性吸附阶段,而PCB-1和PCB-3经过了线性吸附阶段、曲线吸附阶段和平衡阶段。研究结果表明,SBSE-TD-GC-MS可以用于大气中PCBs的样品采集和快速分析。
A method was developed for the determination of Polychlorinated biphenyls(PCBs)in air by stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry(SBSE-TD-GC-MS)using polydimethylsiloxane(PDMS)-coated stir bar for passive air sampler.The optimized conditions for desorption temperature,desorption time and cryofocusing temperature were found to be 280℃,6 min and-40℃,respectively,along with the carry-over of up to 7%for 33 PCB congeners.Linearity,precision and repeatability of the method were investigated.The proposed method showed excellent linearities for 33 PCB congeners,with the correlation coefficients(r)>0.998 for 5 point calibrations.Better precision,intra-day repeatability and inter-day repeatability were obtained with RSDs(relative standard deviation)in the ranges of 0.79%-20.2%(n=8),0.43%-29.8%(n=10)and 3.20%-29.6%(n=20),respectively.Detection limits ranged from 0.01 to 2.51 pg,and the average recovery was 98%±18%.The developed method was applied to monitor PCBs in the atmosphere of Beijing.Eight PCB congeners were detected and the contents were in the range of 2.94-129 pg.PCB-52,PCB-123 and PCB-155 were always in the linear uptake phase,whereas PCB-1 and PCB-3 experienced linear uptake phase,curvilinear uptake phase and equilibrium phase during the sampling campaign of 32 days.The results indicated that SBSE-TD-GC-MS could be employed for sampling and quick determination of PCBs in atmosphere.
作者
李红华
李英明
李晓敏
孙慧中
夏莎莎
张庆华
LI Honghua;LI Yingming;LI Xiaomin;SUN Huizhong;XIA Shasha;ZHANG Qinghua(State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Institute of Quality Standard and Testing Technology for Agro-Products,Chinese Academy of Agricultural Sciences(CAAS),Beijing 100081,China;National Research Center for Geoanalysis,Beijing 100037,China)
出处
《中国环境监测》
CAS
CSCD
北大核心
2024年第2期158-166,共9页
Environmental Monitoring in China
基金
国家自然科学基金资助项目(21307148)
中国科学院技术支撑人才项目(2021)。
关键词
搅拌子吸附
热脱附
多氯联苯
被动大气采样
stir bar sorptive extraction
thermal desorption
polychlorinated biphenyls
passive air sampling
