水中有机氯农药的固相萃取-气相色谱测定法

Determination of Organochlorine Pesticides in Water by Solid Phase Extraction-Gas Chromatography

目的建立水中有机氯农药类化合物的固相萃取．气相色谱测定法。方法水中六六六、DDT采用ODS-C18固相萃取柱富集，正己烷-丙酮混合溶剂洗脱，利用气相色谱仪-电子捕获检测器检测。结果α-六六六的线性范围为1．0～20μg／ml，检出限为2．1ng／L；β-六六六的线性范围为2．5—50μg／ml，检出限为2．8μg／L；γ-六六六的线性范围为1．5～30μg／ml，检出限为2．4ng／L；8．六六六的线性范围为1．5～30μg／ml，检出限为1．7ng／L；p，p＇-DDE的线性范围为2．0～40μg／ml，检出限为20ng／L；p，p＇-DDD的线性范围为2．5～50μg／ml，检出限为15ng／L；o，p’-DDT的线性范围为2．5～50μg／ml，检出限为18ng／L；p,p＇-DDT的线性范围为3．75～75μg／ml，检出限为17ng／L，各回归方程均r≥0．9990。该方法所得的平均回收率为86．5％～95．0％，相对标准偏差为1．8％～3．8％。结论该方法具有灵敏度高、检出限低、操作便捷、结果准确的优点，方法能满足环境水体中痕量有机氯农药的监测要求。

Objective To establish a method for the determination of organochlorine pesticides in water by solid phase extraction （SPE）-gas chromatography. Methods Organochlorine pesticides were extracted from water with ODS-CI8 SPE cartridge, eluted with the mixture solvent of hexane and acetone, gas chromatography equipped with electron captured detector （ECD） was used to analyze the target compounds. Results The linear ranges and limits of detection respectively were 1.0-20 μg/ml, 2.1 ng/L for α-BHC; 2.5-50μg/ml, 2.8 ng/L for β-BHC; 1.5-30 μg/ml, 2.4 ng/L for γ-BHC; 1.5-30 μg/ml, 1.7 ng/L for δ-BHC; 2.0-40 μg/ml, 20 ng/L.for p ,p ＇-DDE;2.5-50μg/ml, 15 ng/L forp ,p ＇-DDT;2.5-50 μg/ml, 18 ng/L for o,p ＇-DDE, 3.75-75 μg/ml, 17 ng/L for p ,p ＇-DDT. The correlation coefficients were above 0.999 0. The average recovery rates were 86.5%-95.0% and the relative standard deviations ranged from 1.8% to 3.8%. Conclusion The method is simple, rapid, sensitive, accurate and applicable to the determination of trace organochlorine pesticides in environmental waters.