采用正己烷作萃取溶剂提取并富集水样中有机氯农药(OCP′s)和多氯联苯(PCB′s),所得提取液经浓缩至约0.5 mL并定容至1.0 mL后,用气相色谱法-电子捕获检测器测定水中有机氯农药和多氯联苯。采用Rtx-5MS和Rtx-1701双柱法根据与标准物质的保留时间相对比进行定性分析;采用Rtx-5MS柱对被测组分按外标法进行定量分析。结果表明:各种农药质量浓度均在0.5~40 μg·L-1范围内与峰面积呈线性关系。有机氯农药和多氯联苯的检出限(3s)在0.001 1~0.004 7 μg·L-1之间。用标准加入法测得其回收率在83.3%~112.1%之间,相对标准偏差(n=7)在4.4%~9.4%之间。

GC chromatography with electron capture detector was applied to the determination of organochlorine pesticides (OCP′s) and polychloro-biphenyls (PCB′s) in water. OCP′s and PCB′s were separated and enriched from water sample by extraction with n-hexane. The extract was concentrated to about 0.5 mL and diluted to 1.0 mL with n-hexane. The double caplillary chromatographic column technique, i.e. use of 2 columns of different polarity (the Rtx-5MS column and the Rtx-1701 column) was adopted in separation and identification of the OCP′s and PCB′s was performed by comparing values of tR of sample with that of standard samples, and quantification was performed by using the external standard method with the Rtx-5MS column. Linear relationships between values of peak area and mass concentration of the OCP′s and PCB′s were found same in the range of 0.5-40 μg·L-1, with detection limits (3s) in the range of 0.001 1-0.004 7 μg·L-1. Recovery of the method was tested giving values of average recovery ranged form 83.3% to 112.1% and RSD′s (n=7) ranged from 4.4% to 9.4%.