吹扫捕集/气相色谱-同位素比值质谱联用测定水体中痕量苯系物单体碳同位素  

Determination on Compound Specific Carbon Isotopes of Trace Benzenes in Water by Purge and Trap/Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry

作　　者：苏静 尹希杰 丁达 漆艳 SU Jing;YIN Xi-jie;DING Da;QI Yan(Information and Testing Support Center,Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China;Soil Pollution Prevention and Control Research Center,Nanjing Institute of Environmental Sciences,Ministry of Ecological Environment,Nanjing 210042,China)

机构地区：[1]自然资源部第三海洋研究所分析测试中心,福建厦门361005 [2]生态环境部南京环境科学研究所土壤污染防治中心,江苏南京210042

出　　处：《分析测试学报》2023年第5期634-640,共7页Journal of Instrumental Analysis

基　　金：国家自然科学基金项目(41976050);海洋三所基本科研业务专项(海三科2018004)。

摘　　要：建立了吹扫捕集(P&T)/气相色谱-同位素比值质谱(GC/C-IRMS)联用测定水体中痕量苯系物单体碳同位素的方法。优化了吹扫时间、吹扫温度和干吹时间,确定最优吹扫捕集效率,并通过测试不同质量浓度的苯系物水溶液,计算水体中痕量苯系物的检出限。结果表明,在35℃下吹扫捕集13 min,干吹时间3 min条件下,水样中苯、甲苯、乙苯、间/对二甲苯、邻二甲苯、苯乙烯、异丙苯的吹扫捕集效率分别为95.0%、90.2%、71.3%、59.1%、69.4%、50.8%和70.1%,7种苯系物单体碳同位素的标准偏差(STD)为0.06‰~0.29‰。7种苯系物的质量浓度在0.50~20.00μg/L范围内与峰面积的线性关系良好,相关系数(r2)为0.998 6~0.999 5,在各浓度下7种苯系物单体碳同位素值的标准偏差为0.090‰~0.48‰,进样量及进样方式的差异不会导致碳同位素分馏。水样中苯、甲苯、间/对二甲苯、邻二甲苯和苯乙烯的检出限为1.00μg/L,乙苯和异丙苯为0.50μg/L。该方法可以极大提高水体中苯系物单体碳同位素的检出限,结果准确可靠,满足水体中痕量苯系物单体碳同位素分析的需求。A gas chromatography/combustion-isotope ratio mass spectrometry(GC/C-IRMS)with purge and trap technique(P&T)was developed for the determination of compound specific carbon iso⁃topes of trace benzenes in water in this paper.Three experimental conditions(purge time,purge tem⁃perature and dry-blow time)of P&T were investigated,and the optimal P&T efficiency was deter⁃mined.The detection limits for trace benzenes in water were calculated by testing aqueous solutions of benzene in different mass concentrations.The results showed that under the conditions of 13 min of purge trapping and 3 min of dry-blowing time at 35℃,the P&T efficiencies for each benzenes(benzene,toluene,ethylbenzene,m/p-xylene,o-xylene,styrene and isopropylbenzene)in water samples could reach 95.0%,90.2%,71.3%,59.1%,69.4%,50.8% and 70.1%,respectively,and the isotope standard deviations(STD)ranged from 0.06‰ to 0.29‰.There were good linear re⁃lationships for the peak areas of seven benzenes and their concentration in ranges of 0.50-20.00μg/L,with their correlation coefficients(r2)of 0.9986-0.9995.The standard deviations for the monomer⁃ic carbon isotope values of the seven benzenes were in the range of 0.090‰-0.48‰ at each concen⁃tration,and the differences between injection concentration and methods could not lead to carbon iso⁃tope fractionation.The detection limits for benzene,toluene,m/p-xylene,o-xylene and styrene in water samples were 1.00μg/L,while those for ethylbenzene and isopropylbenzene were 0.50μg/L.in water with accurate and reliable results to meet the needs for analysis on the monomer carbon iso⁃topes of trace benzene in water.

关 键 词：吹扫捕集 痕量苯系物 单体碳稳定同位素分析 水体 

分 类 号：O657.63[理学—分析化学] X132[理学—化学]