Research On The Determination Of Multi-pesticides Residue In Chinese Herbal Medicine

The use of pesticides provides unquestionable benefits in increasing agricultural production, however, the problem of pesticide residues has potential risk to consumers and pesticide residues become one of the obstructions china's productions to export.Chinese herbal medicine used some pesticides and fungicide during its growth and in china today there is few test technique about Chinese herbal medicine, so take some research on the technique of pesticide residues test will have significance on the improving of exportation. As the special composition of herbal medicine, it will be more complex for the pretreatment. QuEChERS was more and more popular science 2003, which uses acetonitrile as extract solvent, PSA as sorbent, it was used in fruits and vegetables, but with more modified methods were developed, it was used in more and more matrixes. In this study, I mainly discussed how to modify the method so that it can be used in the multi-residue test of Chinese herbal medicine. This study used LC-MS/MS, and the results can fulfill the daily test. Consequences are as follows:1. Based on the original QuEChERS,optimized the extract and purification steps one by one, in the end ,I choose 1% acetic acid in acetonitrile as extract solvent, anhydrous magnesium sulfate to remove water in matrix, homogeneity extraction, for wolfberry, PSA,C18 was used as sorbent, however, citrus uranium ,GCB and toluene must be used to remove pigment. The extract was brilliantly clear after the pretreatment. Compared with SPE, QuEChERS cost little time and less glass ware, requirement of the laboratory is very low, greatly reduced the cost of pretreatment, so it can be widely used in many laboratories.2. Optimized the LC-MS/MS conditions, make it fit for the carbamate pesticides and benzoyl urea insecticides. Firstly, optimize the MS conditions, then the HPLC conditions. This method used ion for qualitative and standard curve for quantitfication, For accurate quantitative, I made a standard curve according to the blank matrix.3. Confirmed by standard recovery, the modified QuEChERS method has good recoveries and smaller standard deviation, can be used on the determination of multi-pesticides residue in Chinese herbal medicine...