On Methods of Sample Pretreatment in GC Determination of Organophosphorus Pesticides in Water

Six organophosphorus pesticides in water were determined by GC-MS, and the methods of sample pretreatment, namely, the automatic solid phase extraction (method 1#) and the automatic liquid-liquid extraction (method 2#), were studied comparatively. It was found that accuracy of method 1# is better than method 2#. Values of recovery found by method 1# were in the range of 73.5%-92.0%, while by method 2# were in the range of 63.7%-89.7%. But more time was required in the sample treatment by method 1# than by method 2#.