The Research On Detection Of Multi-residues Of Organophosphorus Pesticides In Five Chinese Herbal Medicines By HPLC-MS

The application of pesticides has been playing a very important role in agriculture. It greatly improves the output of crops.At the same time, some damages came. Chinese herbal medicine, as a special plant, contributes a lot in people's health. The requirement of Chinese herbal medicine had been growing; resultantly the cultivation of Chinese herbal medicines expanded. Because pesticides are applied to a broad variety of Chinese herbal medicines to reduce loss from insects, Chinese herbal medicines have a high risk of contamination of pesticides.Thus, it is very important to strengthen the study on determination of pesticide residues in Chinese herbal medicines.In this thesis, we developed a method for detecting the multi-residue of Organphosphorus pesticides in Gardenia jasminoides.We optimized the extract, clean up procedures, and then developed a method for the simultaneous detectiong organphosphorus pesticides in G. jasminoides by liquid chromatography tandem mass spectrometry. The detection method was applied to the other four Chinese herbal medicines (Scrophularia ningpoensis, Plantago assiatica Linn, Glycyrrhiza uralensis Fisch and Lonicera japonica Thunb) for the determination of organphosphorate pesticides residue. The main results were summarized as follows:1.We optimized the MS/MS system, chose the suitable liquid chromatography column, mobile phase program and elution program. Methanol and aqueous solution (containing 1% methanoic acid) for mobile phase and selected ion scan mode were used, for the residue analysis of organphosphorus pesticides in Chinese herbal medicines.The results showed that 11 organphosphorus pesticides can be well separated in the selected conditions.2.The author established a HPLC-MS/MS method for the simultaneous determination of 11 Organophosphorus pesticides in Gardenia jasminoides Ellis. Organophosphorus pesticide were extracted by acetonitrile from Gardenia jasminoides Ellis samples and cleaned up with Carb/PSA cartridge and activated carbon, then were detected by HPLC tandem MS/MS.The average recoveries of 11 Organophosphorus pesticides at the concentration levels of 50μg/kg,100μg/kg and 200μg/kg were in the range of 84.0-98.7%,89.7-104.7% and 88.3-103.3%,with the relative standard deviations in the range of 2.4-9.4%,1.6-8.2% and 2.1-9.3%,respectively. The linear ranges of 11 Organophosphorus pesticides were 125-2000μg/kg, and the correlation coefficients were 0.9971-0.9999.The limits of detection ranged from 2μg/kg to 20μg/kg.3.We expanded the applicable range of the method we established to of the detection of the residues in Scrophularia ningpoensis, Plantago assiatica Linn, Glycyrrhiza uralensis Fisch and Lonicera japonica Thunb, a satisfactory result was obtained in the determination of Organophosphorus pesticides in Chinese herbal medicines.4. We conducted the post-extracted addition to study the effects of sample matrix effects on the results of determination. The results indicated that organphosphorus pesticides were impacted by the five Chinese herbal medicines.The majority of effects performed weaken affections.