Dissipation and Processing Factor of Etofenprox and Fenitrothion Residue in Chinese Matrimony Vine by drying
2018
Noh, H.H., National Institute of Agricultural Science, Rural Development Administration, Wanju, Republic of Korea | Lee, J.Y., Research Institute, Residue Research Team, Nonghyeop Chemical, Okcheon, Republic of Korea | Park, H.K., Chungbuk National University, Cheongju, Republic of Korea | Jeong, H.R., Chungbuk National University, Cheongju, Republic of Korea | Lee, J.W., Chungbuk National University, Cheongju, Republic of Korea | Jo, S.H., Chungbuk National University, Cheongju, Republic of Korea | Kwon, H., National Institute of Agricultural Science, Rural Development Administration, Wanju, Republic of Korea | Kyung, K.S., Chungbuk National University, Cheongju, Republic of Korea
BACKGROUND: This study was carried out to determine characteristics of residual pesticides in time-dependent manner and calculate half-lives of the residual pesticides in fresh and dried Chinese matrimony vine. In addition, processing factors were calculated based on the residual concentrations in them. METHODS AND RESULTS: The test pesticides, etofenprox and fenitrothion, were sprayed onto the Chinese matrimony vine plants at once or twice (at seven-day interval) and then samples were collected at 0 (after 3 hours), 1, 3, 5 and 7 days after the last spraying. Dried samples were prepared in hot-air drying oven at 60℃ for 48 hours until water content of less than 20%. Residual concentrations of etofenprox in fresh and dried samples decreased by 54.0-60.9% after 7 days of the last pesticide-application. In case of fenitrothion, the concentrations were found to have decreased by 69.2-76.5%. Processing factors of etofenprox were 2.6-3.0 for the one-time spraying and 2.5-3.0 for the two-time spraying and those of fenitrothion were found to be 1.5-22 for the one-time spraying and 1.6-2.0 for the two-time spraying. First half-lives of etofenprox and fenitrothion in fresh and dried samples ranged from 5.0 to 6.3 and from 3.4 to 4.0 days, respectively. The third half-lives were found to be 15.0-18.9 and 10.2-12.1 days, respectively. CONCLUSION: Residual concentrations of the tested pesticides in the studied crop decreased, but those in the dried samples appeared to have increased. In addition, processing factor and half life were constant regardless of spraying times.
显示更多 [+] 显示较少 [-]