The Analytical Study On Pyrethroid And Organophosphorus Pesticide Residues In Platycodon Grandiflorum And Other Kinds Of Chinese Herbal Medicines

Recent years, organochlorine pesticides is the main study on determination of pesticide residues in Chinese herbal medicines(CHMs), while the research on other types of pesticides is few, such as: pyrethroid and organophosphorus pesticides (Ops),which falls short of the factual contamination in CHMs.A residue analytical method based on solid phase extraction (SPE) and chromatography techniques (high performance liquid chromatography and gas chromatography) was developed and investigated for determination of six pyrethroids pesticides and eight OPs in CHMs,which provided a viable means of analysis for monitoring the pesticide residues in CHMs.一,Study on the residue of pyrethroid pesticides in Platycodon grandiflorum and other kinds of Chinese herbal medicines(一),Determination of six pyrethroid pesticides in Chinese herbal medicines by solid-phase extraction—high performance liquid chromatography Objective:A method for the extraction,clean-up and determination of fenpropathrin,lambda-cyhalothrin,deltamethrin,fenvalerate,permethrin and bifenthrin in CHMs has been developed.The pesticides determination was performed by HPLC. Method: The procedure involved in ultrasonic extraction with petroleum ether ,purification using CARB/NH2 SPE column,followed by separation and quantitative analysis using HPLC.Results: The average recoveries for Platycodon grandiflorum,Pinellia ternate,Scutellria baicalensis,Baphicacanthus cusia were 75.6%～107.5%, 84.4%～96.9%, 84.7%～101.6%, 83.6%～116.6%and relative standard deviation (n=5) were 2.31%～9.85%,1.45%～12.68%,2.96%～13.55%,2.17%～8.00%,respectively. Conclusion: The proposed method has high repeatability and selectivity,it is simple and fast,which can be used for the analysis of six pyrethroid pesticides in CHMs.(二),SPE-GC study on internal standard method for determination of pyrethroid pesticides in Chinese herbal medicinesObjective:A method for the extraction,clean-up and determination of fenpropathrin,lambda-cyhalothrin,deltamethrin,fenvalerate,permethrin and bifenthrin in CHMs has been developed.The pesticides determination was performed by GC.Internal standard method was adopted as quantitative method.Method: The procedure involved in ultrasonic extraction with petroleum ether , purification using CARB/NH2 SPE column,followed by separation and quantitative analysis using GC-ECD, the pyrethroids were quantified by internal standard method.Results: The average recoveries and RSD for Platycodon grandiflorum were in the range of 78.9%～97.8% and 1.17%～11.63%,respectively.The method met the requirement of pesticide residue analysis.Conclusion:A new method for determination six pyrethroid pesticides in CHMs was established by GG with internal standard,which could meet the requirement of pesticide residue analysis.二,Study on the residue of organophosphorus pesticides in Platycodon grandiflorum and other kinds of Chinese herbal medicinesObjective:A method for the extraction,clean-up and determination of dimethoate, dichlorvos, malathion, paration, diazinon, parathion-methyl and phoxim Chlorpyrifos in CHMs has been developed.The pesticides determination was performed by HPLC.Method: The average procedure involved in ultrasonic extraction with ethyl acetate,purification using CARB/NH2 SPE column,followed by separation and quantitative analysis by using reversed-phase HPLC with gradient elution for the baseline separation of the eight pesticides and determined by DAD. The composition and ratio of the mobile phase and UV detection wavelength were optimized, choosing the best of conditions.The preparation for four kinds of samples with eight organophosphorus pesticides was performed by this method.Results: The recoveries for Platycodon grandiflorum , Astragalus membranaceus ,Scutellria baicalensis,Pinellia ternate were78.0%～103.0%,74.5%～102.8%, 75.2%～104.2%,77.0%～108.5%,and relative standard deviation (n=5) were 3.05%～14.28%,3.57%～13.72%,2.32%～11.96%,2.76%～13.77%,respectively.Conclusion: The proposed method has high repeatability and selectivity,it is simple and fast,which can be used for the analysis of eight organophosphorus pesticides in CHMs.