Rapidly Determinating 212 Pesticide Residues In Chinese Herbal Medicine Using Chromatography-tandem Mass Spectrometry With Modified QuEChERS

The Chinese herbal medicine is playing an increasingly important role in treatment of disease. The security problems of Chinese herbal medicine is not only the most basic quality requirement, but also the major factors affecting people’s health. In recent years, the analysis of pesticide residue of Chinese herbal medicine has gained extensive attention, many countries and international organizations have established the evaluation standard, MRLs of pesticides for Chinese herbal medicine. Pesticide residue analysis of Chinese herbal medicine is relatively difficult, not only because of its low residue, and Chinese herbal medicine is relatively complex matrix containing a lot of interfering substances.Therefore, to the trace analysis of Chinese herbal medicine in pesticide residues, it is necessary to establish a simple and effective sample pretreatment methods in combine with a rapid and sensitive analysis technology.This paper focus on the optimization of adsorbent, using new adsorbent MWNTs to remove interfering substances and improve the Qu ECh ERS method to purify the complex samples. Acetonitrile, acetic acid and sodium acetate buffer solution were used as the extraction agent, PSA, C18 and MWNTs were used as adsorbent to remove interfering substances in the experiment. The instrumental conditions of LC-MS/MS and GC-MS/MS,extraction solvent, deceir and adsorbent which the key factors affected the recovery of pesticide were optimized. A novel modified Qu ECh ERS pretreatment method was established to simultaneous determination of 212 pesticides combined with LC-MS/MS and GC-MS/MS, respectively.Under the optimum conditions, the method was validated by analysis of angelica sinensis, asarum sieboldii miq, rehmannia glutinos, uncaria, prunella vulgaris L, millettiareticuiata benth, corydalis yanhusuo, rhizoma chuanxiong, spiked with standard solution. After the determination of 147 pesticides on LC-MS/MS, the recovery values of 3 pesticides( propamocar, thifensulfuron, methyl tepraloxydim)were between 51.2% and 68.4%, and between 70.1% and 119.5% for others. The LOQs of 11 pesticides( omethoate, fenthion-oxon-sulfone, fenamiphos-sulfoxide, disulfoton sulfone, phoxim, acephate,phosmet, paraoxon-ethyl, methidathion, cyhalofop-butyl, and oxadiazon) were varied from 20 to 50μg/kg, and between 5.0 and 20 μg/kg for others. The range of linearity and the correlation coefficient were 5 ~ 500 μg/L and 0.992 ~ 0.999, respectively. The precision of the method was acceptable( 0.1%≤ RSD ≤ 21%). After the determination of 77 pesticides on GC-MS/MS, the recovery values were generally between 63.5% and 120.7%. The LOQs were varied from 5.0 to 20 μg/kg. The range of linearity and the correlation coefficient were 5 ~ 500 μg/L and 0.994 ~ 1.000, respectively. The precision of the method was acceptable( 1.5% ≤ RSD ≤ 19%).This new method has high sensitivity, good selectivity, and good credibility which will meet the requirements of pesticide residue detection standards for Chinese herbal medicine in China.Furthermore, this method may provide a quick and efficient means of analysis for the aim of risk assessment detection, import and export of the Chinese herbal medicine.