Estimation of the Pesticides Transfer Rate during the Preparation of the Oriental Herbal Drug Materials

Background/Objectives: The residual pesticide problem even in Herbal Medicinal Materials (HDMs) has increasingly brought concerns to the patients (consumers). Methods/Statistical Analysis: For the estimation of pesticides' exposure to consumers via herbal drugs, it must be required that the transfer rates (TRs%) of the residual pesticides from raw to the final herbal drug, occurring via processing steps, be determined. The TRs% of 13 pesticides belonging to 6 groups were investigated from 7 HDMs by employing independent drying and/or decoction steps. Residues were quantitated in dried HDMs and decoctions using GC-ECD. Findings: The fate of the pesticide in the HDM (after drying and decoction) was mainly dependent on the nature of the pesticide, and not on the nature of the HDM. However, among the five HDMs, Daechu showed the most universal holding capability for the all tested pesticides even after drying process. The low cumulative average TR% (up to 0.4%), of drying and decoction, was obtained from mevinphos, chlorpyrifos, p,p'-DDE and diazinon, whereas chlorfenapyr (34.3%), bifenthrin (54.3%) and fenvalerate (56.7%) had high cumulative average TR%. Improvements/Application: This TR% s of residual pesticides shall be used for the establishment of sound and cost-effective HDMs management system in the future.