水中16种半挥发性农药的膜式固相萃取-气相色谱-质谱测定法

Determination of 16 kinds of semi volatile pesticide pollutants in water by disk-based solid-phase extraction-gas chromatography/mass spectrometry

目的建立水中16种半挥发性农药的膜式固相萃取-气相色谱（GC）-质谱（MS）测定方法。方法水样（调整pH≤2）经C18固相萃取膜富集,用乙酸乙酯和二氯甲烷洗脱,洗脱液经DryDisk干燥膜,氮吹后定容。DB-35MS毛细管柱分离,采用GC-MS法选择离子扫描模式对水中16种半挥发性农药进行分析,以保留时间和特征离子定性,内标法定量。结果该方法在一定浓度范围（五氯酚：0.1～10.0μg/ml;其余15种半挥发性农药：0.05～5.0μg/ml）内线性关系良好,r≥0.9990;检出限为0.07～0.25μg/L,定量下限为0.21～0.79μg/L,平均回收率为72.8%～126.0%,RSD为3.6%～13.8%。结论该方法有机溶剂用量少,检测种类多,操作简便快速,灵敏度和准确度均较高,适用于饮用水中16种半挥发性农药的测定。

Objecctive To establish a method for the determination of 16 kinds of semi volatile pesticide pollutants in water by disk-based solid-phase extraction-gas chromatography/mass spectrometry. Methods The water samples were extracted and condensed with C18-solid phase extraction disk at pH≤2 and eluted by ethyl acetate-methylene chloride,eluate was dried by DryDisk,then concentrated through N2blowing. A total of 16 kinds of semi volatile pesticide pollutants were separated by capillary column and determined by GC-MS with SIM mode. The pesticide pollutants were identified according to their retention time and characteristic ions and quantified by internal standard method. Results A total of 16 kinds of semi volatile pesticide pollutants in the certain concentration range（pentachlorophenol：0.1-10.0 μg/ml;the remaining compounds：0.05-5.0μg/ml） showed a good linear relation,r≥0.999 0. The limits of detection were 0.07-0.25 μg/L and the quantitative limits were0.21-0.79 μg/L,the average recovery rates were 72.8%-126.0% and RSDs（n=7） were 3.6%-13.8%. Conclusion The method needs less dosage of organic solvent,can be used for multiple kinds of compounds,rapid,sensitive,accurate and applicable to the determination of 16 kinds of semi volatile pesticide pollutants in drinking water.