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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。
Objective To establish a method for the determination of 16 semi-volatile pesticides in water by gas chromatography-mass spectrometry (MS-MS). Methods Water samples (adjusted pH≤2) were concentrated in C18 solid-phase extraction membrane, eluted with ethyl acetate and dichloromethane. The eluent was dried over a DryDisk membrane and the volume was fixed with nitrogen. DB-35MS capillary column, 16 kinds of semi-volatile pesticides in water were analyzed by GC-MS method and ion-scan mode. The retention time and characteristic ions were qualitatively determined by internal standard method. Results The method showed good linearity within a certain range of concentration (pentachlorophenol: 0.1-10.0μg / ml; the remaining 15 kinds of semi-volatile pesticides: 0.05-5.0μg / ml) with r≥0.9990; the detection limit was 0.07 ~ 0.25 μg / L, the lower limit of quantification was 0.21 ~ 0.79μg / L, the average recovery was 72.8% ~ 126.0%, RSD was 3.6% ~ 13.8%. Conclusion This method has the advantages of less amount of organic solvents, more detection types, simple and quick operation, higher sensitivity and accuracy, and is suitable for the determination of 16 semi-volatile pesticides in drinking water.