将水样(250 mL)用正己烷(30 mL)萃取,所得萃取液经蒸发浓缩,定容至1 mL,供气相色谱分析。用VB石英毛细管色谱柱(30 m×0.25 mm,0.25 μm),在120 ℃~230 ℃温度区间采用程序升温方式进行分离,用电子捕获检测器进行测定。11种多氯联苯的检出限(3S/N)在0.01~0.02 ng·L-1之间。以空白水样为基体进行回收试验,方法的回收率在83.5%~96.4%之间,相对标准偏差(n=10)均小于11%。方法用于鄱阳湖6个采样点水样中多氯联苯的测定,在枯水期和丰水期的平均测定值分别为2.34 ng·L-1和1.79 ng·L-1。

Water sample (250 mL) was extracted with n-hexane (30 mL), and the extract was evaporated and made up to 1 mL. VB quartz capillary chromatographic column (30.0 m×0.25 mm,0.25 μm) was used for separation in the temperature range from 110 ℃ to 210 ℃ with programmed temperature elevation. ECD was used in the determination. Values of detection limits of 11 polychlorinated biphenyls were found in the range of 0.01-0.02 mg·L-1. Using blank water sample as matrix, test for recovery was made by standard addition method, giving recovery in the range of 83.5%-96.4% with RSD′s (n=10) less than 11%. The proposed method was applied to the determination of polychlorinated biphenyls in water samples from 6 sampling points of Poyang Lake, giving values of average results of 1.79 ng·L-1 in high-water season and 2.34 ng·L-1 in low-water season.