顶空固相微萃取-气相色谱法测定环境中挥发性有机物

目的 建立顶空固相微萃取-气相色谱法同时测定环境样品中苯系物、氯代甲烷类等挥发性有机物的方法.方法 采用未涂任何固定液的光纤作为萃取头,自行制作的固相微萃取SPME装置,通过顶空固相微萃取气相色谱法(HS-SPME-GC)测定氯代甲烷和苯系物,并对测定的萃取条件和色谱条件进行了优化.结果 方法的线性范围为二氯甲烷014～75.7μg/L、三氯甲烷0.24～84.5μg/L、四氯化碳0.45～137.1μg/L、苯0.03～12.6μg/L、甲苯0.10～24.8μg/L、乙苯0.06～24.7μg/L、二甲苯0.13～24.8μg/L,相关系数为0.9915～0.9979;检出限为二氯甲烷0.14μg/L、三氯甲烷0.24μg/L、四氯化碳0.45μg/L、苯0.03μg/L、甲苯0.10μg/L、乙苯0.06μg/L、二甲苯0.13μg/L;样品加标回收率为80.0%～111.6%,相对标准偏差为4.4%～8.1%.结论 该法简便、快速、灵敏度高、重现性好、分析成本低.

Determination of Volatiles in Environment Using Solid-Phase Microextraction and Gas Chromatography

Objectives A method for the simult aneous determination of methyl chlorides(dichloromethane,trichlor omethane and tetrachloro methane)and BTEX(benzene,toluene,ethylbenzene and xylenes isomers)in env ironmental samples were studied using headspace solid-phase micro-extraction(SPME)and gas chromatography.Methods Solid phase microextraction with uncoated fiber in the headspace and capillary gas chromatography were used to determinate methyl chlorides and BTEX.The extractive and chromatog raphic conditions were optimized.Results Linear limits of the method: dichlormethane 0.14-75.7μg/L,trichloromethane 0 24-84.5μg/L,tetrachlor methane 0.45-137.1μg/L,benzene 0.03 -12.6μg/L,toluene 0.10-24.8μg/L,ethylbenzene 0.06-24.7μg/L,xylenes isomers 0.13-24.8μg/L.The cofficient of correlation ranged form 0.991 5-0.997 9,limit of detection of volatiles above were 0.14μg/L、0.24μg/L、0.45μg/L、0.03μg/L、0.10μg/L、0.06μg/L、0.13μg/L.The recoveries and coefficient of variation in sample determination ranged from 80.0%-111.6% and from 4.4%-8.1%,respectively.Conclusion This method was simple,fast,accurate with high reproducibility,high sensitivity and low cost.