水中15种有机氯农药的固相膜萃取-气相色谱-质谱测定法

Determination of 15 organochlorine pesticides residues in water by SPE disk-gas chromatogramphy-mass spectrometry

目的建立了水中15种有机氯农药残留的固相膜萃取-气相色谱-质谱(SPE disk-GC-MS)同时测定法。方法调整水样pH 7,经C18固相膜萃取富集,用乙酸乙酯和正己烷依次洗脱目标物,洗脱液过DryDisk干燥膜,氮吹浓缩后用正己烷定容至1 ml。用HP-5MS毛细柱分离,在选择离子扫描(SIM)模式下对水中15种有机氯农药进行分析,以保留时间和特征离子定性,外标法定量。结果在2~100μg/L浓度范围内,所得15种有机氯农药的回归方程均呈较好的线性关系,r≥0.999。该方法的检出限为0.005 5~0.011μg/L,定量下限为0.013~0.026μg/L;平均回收率为81.8%~108.2%,RSD为2.2%~9.8%。结论该方法具有快速、简便、灵敏等优点,可用于水样中痕量15种有机氯农药的测定。

Objective To develop an analytical method for simultaneous determination of 15 organochlorine pesticides residues in waters samples by solid phase disk extraction and gas chromatography-mass spectrometry(GC-MS).Methods The water samples(adjusted to pH 7)were extracted and condensed with C18-solid phase extraction disk.The target analytes were eluted with ethyl acetate and hexane,the eluent was dried by DryDisk,then concentrated through N2 blowing and redissolved in 1 ml hexane.After separation by HP-5 MS capillary column,the 15 organochlorine pesticides were analyzed by gas chromatographymass spectrometry(GC/MS)under selected ion monitoring(SIM)mode.The organochlorine pesticides were identified according to their retention time and characteristic ions and quantified by internal standard method.Results The calibration curves of 15 organochlorine pesticides showed a good linearity in the range of 2-100μg/L,the correlation coefficients were more than 0.999.The limits of detection(LOD)were 0.005 5-0.011μg/L,the limits of quantitation(LOQ)were 0.013-0.026μg/L respectively.The average recovery rates were 81.8%-108.2%,and the RSDs were 2.2%-9.8%.Conclusion This method shows the advantages of simplicity,rapidness and sensitivity,and is applicable to the determination of trace organochlorine pesticides in water.