顶空固相微萃取-气相色谱-质谱法同时测定饮用水源水中24种VOCs

建立了同时测定饮用水源水中24种挥发性有机物(VOCs)的顶空固相微萃取-气相色谱-质谱法.用75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取柱顶空萃取水样中的VOCs,VOCs用气相色谱-质谱联用仪检测,采用内标法定量.对萃取柱涂层、样品盐度、萃取温度和萃取时间等样品前处理条件进行了优化,VOCs的检出限在0.03～0.31 μg/L之间,线性相关系数r＞0.996(二氯甲烷和三氯甲烷除外).对饮用水源水实际水样0.50μg/L和1.00 μg/L两个加标浓度水平的回收率进行了测定,三氯甲烷回收率均值分别为104％和142％,其余VOCs回收率分别为90.0％～120％和88.0％～110％,除二氯甲烷和三氯甲烷外,其余VOCs测定结果的相对标准偏差均小于15.0％(n=6).该方法适用于饮用水源水中挥发性有机物的监测分析.

Simultaneous Determination of 24 VOCs in Drinking Source Water by Head Space Solid Phase Microextraction Method Coupled with Gas Chromatography and Mass Spectrometry

Head space solid phase microextraction(HS-SPME) method was developed to determinate 24 volatile organic compounds(VOCs) in drinking source water.75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS) fiber was used to extract VOCs in samples,and VOCs were detected by gas chromatography and mass spectrometry(GC-MS) with selective ion mass(SIM) mode and internal standard quantitative method.The selection of SPME coatings,addition of NaCl,extraction temperature and extraction time were optimized.The detection limits were 0.03-0.31 μg/L and the correlation coefficients were more than 0.996(except for dichloromethane and chloroform).The average values of recoveries obtained were 90.0%-120% and 88.0%-110%,RSD of detection results were less than 15.0%(except for dichloromethane and chloroform) in drinking source water samples spiked with 0.50 μg/L and 1.00 μg/L VOCs(n=6).HS-SPME method is capable to the determination of 24 VOCs in drinking source water sample.