Determination of 31 organophosphorus pesticide residues in tea by solid phase extraction-gas chromatography

Objective:To establish a method for determining 31 organophosphorus pesticide multi-residues in tea.Methods:The samples were extracted with acetone,then pre-purified by passing through Solid Phase Extraction Carbon/Amino.The residues of 31 organophosphorus pesticide in teas were identified and quantified simultaneously by gas chromatography with FPD.Results:In DB-5 Column,31 pesticides were separated from each other,and the liner of standard curve were broad and the liner relationship of standard curve were good(r≥0.997).The average recoveries were 72.0%～100.2% in teas.The relative standard deviations(RSD) were 1.7%～12.7% and the range of minimum detection limits was 2.9 μg/kg～12.6 μg/kg.Conclusion:This method is of good accuracy,high repeatability,sensitivity and less interferences from impurities.This method has met the requirement of analysis method of pesticide multi-residues.