Determination of the residue of dichlorovos, methyl parathion and malathion in Flos Lonicerae by capillary gas chromatography

Objective: To develop a capillary gas chromatography method for determining the residue of dichlorovos, methyl parathion and malathion in Flos Lonicerae. Methods: The samples were treated with microwave extraction and separated by HP-5 capillary column(25 m×0.32 mm, 0.17 μm) with FPD. Highly pure nitrogen was used as carrier gas,and the flow rate was 20 ml/min. Hydrogen flow rate was 45 ml/min, and air flow rate was 450 ml/min. Temperature programming from 120℃ to 230℃ was 10℃/min;injector temperature was 250℃; detector temperature was 260℃. The mode of injection was splitless. Results: The linear range of dichlorovos, methyl parathion and malathion was 0.25~3.00 μg/ml. When the S/N was 2, the detection limit of dichlorovos was 0.3 ng, methyl parathion was 0.15 ng,and malathion was 0.2 ng.The average recovery of dichlorovos was 88.7% with RSD of 2.1%, methyl parathion was 89.7% with RSD of 1.7% and malathion was 90.6% with RSD of 1.1%.Conclusion: The method is easy, accurate and suitable for determining the residue of dichlorovos, methyl parathion and malathion in Flos Lonicerae.