固相微萃取-气相色谱法测定水中痕量苯系物

摘要

提出了固相微萃取样品-气相色谱法测定水中7种苯系物（苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯和异丙苯）的含量。为使固相微萃取达到更高的效率，选择75μm的CAR／PDMS作为萃取头的涂层，萃取温度及时间为20℃和40min，在10mL试样溶液中加入氯化钠4g作为盐析剂。用DB-FFAP毛细管色谱柱分离，氢火焰离子化检测器检测。7种苯系物的质量浓度均在1．00-500μg·L^-1范围内与其峰面积呈线性关系，方法的检出限（3S／N）在0．12～0．19μg·L^-1之间。方法用于4种环境水样分析，加标回收率在93．3％～104．2％之间。%GC with sample pretreatment by solid phase micro-extraction （SPME） was applied to the determination of 7 benzene homologues, i. e. , benzene, methylbenzene, ethylbenzene, p-xylene, m-xylene, oxylene and cumin, in water samples. To attain a higher efficiency for SPME, the 75 μm CAR/PDMS coating was applied to the micro-extractor, and the extraction was carried out at 20 ℃ for 40 min, with addition of 4 g NaCl to 10 mL of sample solution as salting out agent. The analyte were separated on DB-FFAP capillary column and detected by hydrogen FID. Linear relationships between values of peak area and mass concentration of the 7 benzene homologues were kept in the same range of 1.00-500 μg · L^-1 , with detection limits （3S/N） in the range of 0. 12--0. 19μg · L^-1. The proposed method was applied to the analysis of 4 environmental water samples, giving values of recovery found by standard addition method in the range of 93.3%-104. 2%.