부산대학교 도서관

Residue of pesticides was difference depending on the type of pesticide, drying and processing conditions. This study was carried out to elucidate residual characteristics of spirotetramat and its metabolites in ginseng and determine its processing factors and reduction factors in processed products, such as dried ginseng and red ginseng. The pesticide used in the study spirotetramat 22% suspension concentrate, which was diluted 2,000 times according to Korean safety standards and treated two times at 7-day intervals until 14 days before harvest. After last application of pesticide on the study field, the ginseng samples were collected at one time on the expected harvest date, and processed into dried ginseng and red ginseng. In order to investigate the decline pattern of spirotetramat and its metabolites in/on ginseng, fresh ginseng samples were collected on days 0, 3, 7, 14, 21 and 30 after last application of pesticide. The extraction of pesticides was carried out by modified the Korea Food Standards Codex sample extraction and determination was performed using LC-MS/MS. The method was validated with an LOQ of 0.005 mg/kg for fresh ginseng and its processed products. Concurrent mean recoveries (n=15) of spirotetramat and its metabolites at three fortified levels were in the range of 105.06±3.87 for fresh ginseng, 99.41±2.53 for dried ginseng and 103.31±3.12% for red ginseng. In residue study, the results from three trials show that mean total residues of spirotetramat in fresh ginseng were from 0.007 to 0.034 mg/kg. Mean spirotetramat residues in the processed products such as dried ginseng and red ginseng were from 0.020 to 0.115 and 0.023 to 0.053 mg/kg, respectively. In decline study, the results from three field trials show that spirotetramat residues in ginseng were gradually decreased with time. Mean processing factors of spirotetramat for the processed products of ginseng from 2.81 to 3.39 for the dried ginseng, from 1.56 to 3.58 for the red ginseng. The reduction factors of spirotetramat for the processed products of ginseng ranged from 0.57 to 0.74 for the dried ginseng, from 0.34 to 0.72 for the red ginseng.