水中6种有机磷农药的固相膜萃取-气相色谱-串联质谱测定法

Determination of six organic phosphorus pesticides in water by chromatogramphy-tandem mass spectrometry with solid phase disk extraction

目的建立水中6种有机磷农药(敌敌畏、乐果、甲基对硫磷、马拉硫磷、毒死蜱、对硫磷)的固相膜萃取-气相色谱-串联质谱(GC-MS)测定方法。方法水样p H控制在3.0~7.0,经HLB固相萃取膜萃取后,用乙酸乙酯洗脱。采用DB-5MS毛细管柱分离,在选择离子扫描(SIM)模式下测定,外标法定量。结果在0.05~2.0 mg/L的线性范围内,所得6种有机磷农药的回归方程均呈较好的线性关系,r>0.998。方法的检出限为0.07~0.15μg/L,定量下限为0.25~0.40μg/L,平均回收率为87.2%~105.8%,RSD为2.1%~5.3%。结论该方法有机溶剂用量少,操作简便快速,灵敏度和准确度均较高,适用于水中6种有机磷农药污染物的测定。

Objeective To develop a method for the determination of six organic phosphorus pesticides （dichlorvos, dimethoate, methyl parathion, malathion, chlorpyrifos, parathion） in water by gas ehromatogramphy-tandem mass spectrometry （GC-MS） with solid phase disk extraction. Methods The water samples were extracted by HLB solid phase disk at pH 3-7.0, and eluted by ethyl acetate. After separation on a DB-SMS capillary column, the herbicides were analyzed by gas chromatography-tandem mass spectrometry （GC-MS） under selected ion monitoring （SIM） mode and quantified by external standard method. Results The calibration curves showed a good linearity in the range of 0.05-2.0 mg/L,r〉 0.998. The limits of detection were 0.07-0.15 μg/L and the quantitative limits were 0.21-0.79μg/L. The average recovery rates were 87.2%-105.8% and RSDs were 2.1%- 5.3%. Conclusion The developed method needs less dosage of organic solvent,fast,sensitive,accurate and applicable to the determination of six kinds of organic phosphorus pesticides in water samples.