Determination of 29 pesticide residues in water by solid phase extraction-gas chromatography

A method was developed for the determination of 29 pesticide residues in ground water using the combination of solid phase extraction (SPE) and gas chromatography.Cartridges of Envi-18 were selected for extracting those pesticides and n-hexane-acetone (1∶1,V/V) as eluting solvent.The average recoveries of these pesticides at three spiked levels (0.1,1.0 and 10 μg/L) ranged from 60% to 111% with the relative standard deviations (RSD) ranged from 1.2% to 6.4%.The limit of detection(LOD) were from 5 to 50 ng/L.The method is easy,fast and sensitive,which can meet the requirements for simultaneous determination of multi-pesticide residues in water samples.