국립농산물 품질관리원 출하 전 농산물 검사시 얼갈이배추에서 검출빈도가 높은 chlorothalonil, indoxacarb, lufenuron, metalaxyl 및 methomyl 등 농약 5종에 대하여 수확 10일전에 대상약제를 살포하고 생산기간중의 경시적인 잔류량 변화를 조사하고 이를 토대로 반감기를 산출하였다. 얼갈이배추의 생산기간동안 표준량 살포 처리구에서 chlorothalonil의 잔류량은 55.58 mg/kg(0 day)에서 20.08 mg/kg(10 day)로 감소하고, 반감기는 7.45일 이었으며, indoxacarb는 7.85 mg/kg(0 day)에서 1.46 mg/kg(10 day)로 감소하고 반감기는 4.2일 이었으며, lufenuron는 1.57 mg/kg(0 day)에서 0.49 mg/kg(10 day)로 감소하고 반감기는 5.85일 이었으며, metalaxyl은 8.12 mg/kg(0 y)에서 0.10 mg/kg(10 day)로 감소하고 반감기는 1.75일 이었고 methomyl은 11.51 mg/kg(0 day)에서 0.80 mg/kg(10 day)로 감소하고 반감기는 2.42일 이었다. 또한 배량 처리구에서의 반감기는 chlorothalonil 9.05일, indoxacarb 7.09일, lufenuron 8.82일, metalaxyl 3.32일, methomyl 2.72일 이었다.
In order to know the residual pattern of some pesticides and predict to the degradation period until below MRL, we experimented chlorothalonil, indoxacarb, lufenuron, metalaxyl and methomyl for Chinese cabbage. They were frequently detected pesticides in Chinese cabbage by NAQS (National Agricultural product Quality management Service) monitoring survey. In this experiment, we sprayed those pesticides 10days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day samples to establish logical equation and to calculate $DT_{50}0$. During the cultivating period, the residue amount of chlorothalonil was changed from $55.58;mg;kg^{-1}$ (0 day) to $20.08;mg;kg^{-1}$ (10 day), $DT_{50}$ was 7.45 days, indoxacarb was $7.85;mg;kg^{-1}$ (0 day) to $1.46;mg;kg^{-1}$ (10 day), and 4.2 days, lufenuron was $1.57;mg;kg^{-1}$ (0 day) to $0.49;mg;kg^{-1}$ (10 day), and 5.85 days, metalaxyl was $8.12;mg;kg^{-1}$ (0 day) to $0.10;mg;kg^{-1}$ (10 day), and 175 days, and methomyl was $11.51;mg;kg^{-1}$ (0 day) to $0.80;mg;kg^{-1}$ (10 day), and 2.42 days at single dose application, respectively. The $DT_{50}$ of double amount in those pesticides were 9.05 days in chlorothatonil, 7.09 days in indoxacarb, 8.82 days in lufenuron, 3.32 days in metalaxyl, and 2.72 days in methomyl, respectively.
