The Analysis Of Multipesticide Residues In Du Zhong,lonicera Japonica And Cantonese Herbal Tea By GC-MS

Traditional Chinese Medicine?TCM?is one of the most precious treasures in the long history river of Chinese resplendent culture.The development and effective utilization of these precious resources have a long history,they build the foundation of smoothly development at Traditional Chinese medicine and pharmacy.Due to the more standards of pesticide residue published by the importing countries,the abuse of pesticides has led to the economic decline of TCM,with the increasing demand for pesticide residues in TCM,the detection of pesticide residue in traditional Chinese herbal medicines has become a major research direction.Therefore set a rapid,efficient,accurate,sensitive pesticide detection method on TCM is urgently needed.In this experiment,we used gas chromatography mass spectrometer combined with three different pretreatment methods to study the pesticide residue of TCM in different types of matrix materials.The specific research content is as follows:1.Developed a multi-residue method for detecting the resduce of 16 species of pesticides on Du zhong?Eucommia ulmoides Oliver?.In this chapter,the solid phase extraction method was used to detect the 16 pesticide residues on the eucommia ulmoides matrix.By designing single factor variable experiments,various parameters that may affect the extraction efficiency was analysised,such as the type and volume of the extracted solvent,the volume and type of the leacheate,the type and amount of cleaning agent material,etc.,together with the use of GC-MS detection to find the best pre-treatment process.From the determination of the optimization of the pre-treatment method,finally chose 20 mL acetonitrile as extraction solvent,cleanert C18/PSA/C18 SPE cloumn as a purification material,10mL acetonitrile-toluene?v:v=2:1?as eluent to carry out the experiment.Matrix-matching method was used to evaluate the matrix effect of each pesticides on Du zhong,and the accuracy of the method was also investigated.Under these conditions,16 pesticides had good linearity in the concentration range of 0.01-5.0 mg/kg.The detection limit was 0.06-0.83?g/kg,indicating that the method has high sensitivity;three concentration gradients were added to recover the experiment,and the added recovery rate was in the range of 79.6-109.2%,indicating that the method has high accuracy and good stability,it can meet the experimental requirements of pesticide residues.2.A method for the determination of 16 kinds of pesticides residues in Lonicera japonica Thunb by QuECHERS-GC-MS was established.By designing Orthogonal test for all factors that may affect extraction and purification?such as the type and volume of extraction solvent,combination and amount of cleaning agent species,and ultrasonic extraction time?,through the test analysis,the optimal parameter was A₂B₂C₃D₁ as follows:20 mL acetone was used as the extraction solvent,ultrasound-assisted extraction was performed for 30 min,and 100 mg PSA,100 mg C18,and 10 mg GCB were used as purifiers for experiments.Matrix matching method was used to evaluate the matrix effect of each pesticide on honeysuckle,and the accuracy of the method was also examined.Under these conditions,16 pesticides had a good linear relationship within the concentration range of 0.01-5.0 mg/kg.The detection limit of the method was calculated in the range of0.43-3.47?g/kg according to the concentration corresponding to the tripled signal-to-noise ratio,indicating that the method has high sensitivity;three concentration gradients were added to analysis the recovery of the experiment,and the measured recovery rate was Within the range of 82.3-102.5%,it shows that this method has high accuracy and can meet the detection requirements of pesticide residues in Eucommia.Thirty batches of randomly purchased samples were tested and it was concluded that different batches of bifenthrin and fenvalerate were detected in the honeysuckle matrix,and the content was slightly higher.Therefore,honeysuckle production should focus on monitoring the use of pyrethroids.3.A method for the determination of 4 pesticide residues in Cantonese herbal tea by dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry was studied.Various factors that may affect the extraction and purification were investigated including the types and volumes of extractants,the volume of dispersants and the volume of dispersants.Finally,the optimum parameters for each factor were selected,140?L of toluene was used as the extractant and 800?L of acetone as the dispersant.Matrix-matching method was used to evaluate the matrix effects of various pesticides on Cantonese herbal tea.The accuracy of the method was also examined.Under these conditions,the linearity of the four pesticides in the concentration range of 0.01-5.0 mg/kg was good.The detection limit calculated according to the tripled signal-to-noise ratio corresponds to a detection range of 1.64 to 3.56?g/kg,indicating that the detection method has a high sensitivity;three concentration gradient addition recovery experiments were performed,and the recovery rate was measured from 87.3 to 113.8.%,indicating that the accuracy of the experimental method is good;the relative standard deviation of five replicates between 0.85-7.26%indicates that the method is of high precision and can fully meet the detection requirements of Cantonese herbal tea.This method is applied to ten batches of actual samples,only a few traces of dimethoate were detected.