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目的建立搅拌棒吸附萃取(SBSE)-热脱附-气相色谱/质谱联用法测定地下水样中54种挥发性有机物(VOCs)方法。方法将涂有聚二甲基硅氧烷(PDMS)的搅拌棒置于20 ml水样中以1 500 r/min萃取20 min后热脱附-气相色谱质谱仪检测,并分别对影响SBSE萃取效率的条件进行优化。结果方法检出限为0.03~6μg/L,54种VOCs的线性相关系数为0.994 3~0.999 9,RSD范围在1.09%~5.02%(n=10),平均加标回收率在81.6%~99.6%(n=10)。结论方法简便快速,准确度和灵敏度高,检出限低,稳定性好,干扰小,线性范围宽,无有机溶剂污染,可满足地下水样中54种痕量VOCs的分析测定。
Objective To establish a method for the determination of 54 volatile organic compounds (VOCs) in groundwater samples by stir bar sorption extraction (SBSE) -thermal desorption-gas chromatography-mass spectrometry. Methods A stir bar with polydimethylsiloxane (PDMS) was placed in a 20 ml water sample and extracted at 1 500 r / min for 20 min. The samples were determined by thermal desorption-gas chromatography-mass spectrometry (GC-MS) Efficiency conditions are optimized. Results The detection limits were 0.03-6 μg / L. The linear correlation coefficients of 54 VOCs ranged from 0.994 3 to 0.999 9. The RSD ranged from 1.09% to 5.02% (n = 10). The average recoveries ranged from 81.6% to 99.6 % (n = 10). Conclusion The method is simple and rapid with high accuracy and sensitivity, low detection limit, good stability, small interference, wide linear range and no organic solvent contamination. It can meet the analytical determination of 54 trace VOCs in groundwater samples.