Determination of nine pesticide residues in fruits by dispersive-SPE-gas chromatography.

A rapid,simple and sensitive method was developed for the simultaneous determining of nine pesticide residues(1-BCH,3-BCH,chlorpyrifos,chlorpyrifos-methyl,dichlofluanid,folpet,p,p′-DDD,fenpropathrin,cyhalothrin) in fruits by dispersive solid phase extraction-gas chromatography.The target pesticides in fruits were extracted by acetonitrile and cleaned up by dispersive solid phase extraction by using primary secondary amine(PSA) and C_18 dispersive sorbent.The analytes were detected by gas chromatography with electron capture detector(ECD),and quantified by external standard.With the optimal chromatogram conditions,the good linearities were obtained ranging from 0.000 5 mg/L to 0.100 0 mg/L for nine pesticides.The detection limits of nine pesticides were from 0.000 2 mg/kg to 0.002 0 mg/kg.The average recoveries ranged from 74.4% to 115.9% at fortified levels from 0.01mg/kg to 0.10 mg/kg.The relative standard deviations(RSD) were less than 13.7%.The method of dispersive SPE-GC established in this study could be used for detecting the pesticide residues in fruits.