用SPME测定珠江河口水体中的PCBs

Rapid determination of PCBs in seawater of Pearl River Delta by solid-phase microextration

报道了利用SPME技术结合电子捕获检测气相色谱 (ECD)测定珠江入海河口水体中PCBs有机污染物的含量 ,并讨论了SPME装置萃取PCBs的主要影响因素。结果表明 :在选取一定的萃取纤维头 (10 0 μmPDMS)后 ,影响萃取效果的主要因素是萃取时间的长短 ,其次为萃取的温度和pH值。在各个影响因素及不同水平处理中 ,以萃取时间 30min、萃取温度 35℃、pH值 7.2、搅拌速度 10 0 0r/min为最理想。在该种条件下测定了珠江入海四大口门虎门、横门、蕉门和斗门河口水体中PCBs含量分别为 2 .70 1、0 .999、2 .82 8和 1.16 1ng/L。

The effect has been studied under different conditions (including time, temperature, pH and the velocity of stir bar) upon the determination of polychlorinated biphenyls using solidphase microextraction (SPME) with a 100 μm poly (dimethylsoloxane) (PDMS) fiber and gas chromatography with elctroncapture detection (GCECD). The result shows that time has the highest effection, temperature, pH value and velocity of stir bar following. The best result appears in the treatment with the extraction of time 30 min, temperatue 35℃, pH 7.2, and the study has been made upon the concentrations of polychlorinated biphenyls (PCBs) in water in four main estuaries-(Humeng, Jiaomeng, Hengmen and Doumen) of Pearl River Delta during the period May～June and Oct.～Nov. in 2000 separately. The result shows that the average PCBs concentration were 2.701, 0.999, 2.828 and 1.161 ng/L in Humen, Jiaomeng, Hengmen and Doumen.