Translocation of Tolclofos-methyl from Ginseng Cultivated Soil to Ginseng (Panax ginseng C. A. Meyer) and Residue Analysis of Various Pesticides in Ginseng and Soil

Abstract

Recently, some of the previous studies reported that tolclofos-methyl is still exist in ginseng cultivated soil, even though it is has been banned for ginseng. Therefore, the current study was aimed to examine the levels of absorption and translocation of tolclofos-methyl from ginseng cultivated soil to ginseng root and leaf·stem for the period of 1 year. For this study, ginseng plants were transplanted in pots and treated with 5.0 mg kg −1 of tolclofos-methyl (50% WP). At the end of each interval periods (every three months) the samples (soil, roots and leaf·stems) were collected and analyzed the absorption and translocation levels of tolclofos-methyl using gas chromatography and mass spectrometry (GC-MS). The limit of quantitation of tolclofos-methyl was found to be 0.02 mg kg −1 and 70.0~120.0% recovery was obtained with coefficient of variation of less than 10% regardless of sample types. In this study, a considerable amount of translocation of tolclofos-methyl residues were found in soil (4.28 to 0.06 mg kg ). The results show that the tolclofos-methyl was absorbted and translocated from ginseng cultivated soil to ginseng root and ginseng leaf·stem and found to be decreased time-coursely. Secondly, we were also analyzed soil, root and leaf·stems samples from Hongcheon, Cheorwon, Punggi and Geumsan by GC-MS/MS (172 pesticides), LC-MS/MS (74 pesticides). In this study, 43 different pesticides were detected (0.01~7.56 mg kg −1 ) in soil, root and leaf·stem. Further, tolclofos-methyl was detected 4 times separately in root sample alone which is less (0.01~0.05 mg kg −1 ) than their maximum residual limit (MRL) in ginseng. Consequently, the results from both studies indicate the residues of tolclofosmethyl found in ginseng cultivated soil and ginseng ensuring their safety level. Moreover, long-term evaluations are needed in order to protect the soil as well as ginseng free from tolclofos-methyl residues.