Study On The Analysisi Methods Of Pesticide Residues In Three Chinese Herbs

Excessive pesticide residues not only harm to our health but also damage the environment and threat the wildlife and plants through the food chain. With the emphasis on health and the deepening understanding of pesticide residues, people pay more attention to the pesticide residues in Chinese herbals. Currently, the most of multi-pesticide residues analyze fruits and vegetables. By contrast, there is less study of multipesticide residues in Chinese herbals. So, it is important meaning to establish the analytical method of multi-pesticide residues in Chinese herbals. This study selected ginseng, chrysanthemum and rhizome corydalis with their representation of medicinal and edible to establish the analytical method of gas chromatography-tandem mass spectrometry(GC-MS/MS) 、gas chromatography- mass spectrometry(GC-MS) and high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS). The main contents are as follows:1. A solid phase extraction gas chromatography-tandem mass spectrometry(SPE GC-MS/MS) and solid phase extraction negative chemical ionization gas chromatography-mass spectrometry(SPE NCI-GC-MS) method were developed for the simultaneous determination of multi-pesticide residues in ginseng, chrysanthemum and rhizome corydalis. The samples were extracted by mix solution of acetone-dichloromethane, cleaned up by PestiCarb/NH2 solid phase extraction column and analyzed in the electron impact-gas chromatography-tandem mass spectrometry(EI-GC-MS/MS). Those compounds who don’t suit analyzed by EI-GC-MS/MS, they are suitable for detecting by negative chemical ionization-gas chromatography-mass spectrometry(NCI-GC-MS) by comparing the experimental. The limits of quantitation(LOQ) of each target compound can reach 10 μg/kg.2. A high performance liquid chromatography-tandem mass spectrometry by online cleanup(Online cleanup HPLC-MS/MS) method was developed for the simultaneous determination of multi-pesticide residues in ginseng, chrysanthemum and rhizome corydalis. The samples were extracted by acetonitrile and cleaned up by QuEChERS after concentration and dissolved by 2.0 ml methanol, Then cleaned up by TurboFlow online cleanup, The separation was performed on C18 column with gradient elution using methanol-0.1% formic acid and ammonium acetate mix solution, monitored by multiple-reaction monitoring and detected by tandem mass. It simplified the pretreatment.