固相萃取-GC-MS法测定水中四氯联苯

建立全自动固相萃取-气相色谱-质谱法检测水中微量四氯联苯的方法。采用全自动固相萃取装置配有C_(18)固相萃取盘富集浓缩水中四氯联苯后,用乙酸乙酯和二氯甲烷洗脱,以CD-5MS毛细管色谱柱分离,气相色谱质谱法测定水中四氯联苯的含量。对水样的洗脱剂、萃取流速、pH值、甲醇加入量等进行了优化试验,四氯联苯PCB52,PCB77,PCB81的质量浓度在5.00~50.0μg/L范围内与色谱峰面积呈良好的线性,检出限分别为0.002,0.003,0.002μg/L;加标回收率分别为90.9%,92.7%,95.4%;测定结果的相对标准偏差均小于3%(n=7)。该方法灵敏度高,适用于水样中痕量四氯联苯的监测。

Determination of Four PCBs in Water by Solid Phase Extraction-Gas Chromatography-Mass Spectrometry

Automatic solid phase extraction–gas chromatography mass spectrometry was set up to detect four polychlorinated biphenyls(PCBs) in water. Four PCBs were enriched and concentrated by automaticsolid–phase extraction plant equipped with C18, eluted by using ethyl acetate and dichloromethane,then separated by CD–5 MS capillary chromatographic column, the content of four PCBs was detected by gas chromatography mass spectrometry. The elution agent of water,extraction of water flow rate,pH value,the amount of methanol and other conditions were studied and optimized. The concentration of four PCBs such as PCB52,PCB77,PCB81 was linear with chromatographic peak area in the range of 5.00–50.0μg/L, the detection limits were 0.002,0.003,0.002μg/L, respectively. The average recovery rate of PCB52,PCB77,PCB81 were 90.9%,92.7%,95.4%, respectively, and the relative standard deviation of determination results was less than 3%(n=7). This method is suitable for trace monitoring of four PCB inwater with high sensitivity.