Residue analysis of insecticide thiodicarb in sweet persimmon and its safety evaluation

The residue analysis of the insecticide thiodicarb in sweet persimmon was analyzed with a gas chromatograph equipped with nitrogen phosphorus detector(NPD) to evaluate efficacy of analysis method and safety of thiodicarb in persimmon. Minimum detectable amount of methomyl oxime, hydrolysate of thiodicarb, was 0.2 ng and detection limit of thiodicarb was 0.05 ppm. The mean recoveries evaluated from untreated samples spiked at 0.5 ppm and 2.5 ppm were $93.9{\pm}3.9$ and $92.8{\pm}2.0%$, respectively. When thiodicarb was sprayed onto the sweet persimmon two times until 40 and 30 days before harvest, three times until 40, 30 and 21 days before harvest, and four times until 40, 30, 21 and 14 days before harvesting, the mean residual amount in sweet persimmon were $1.50{\pm}0.04$, $1.86{\pm}0.04$ and $2.11{\pm}0.12$ ppm, respectively. It would be safe when thiodicarb 40% WP is treated four times 14 days before harvesting to control fruit moth in sweet persimmon.

살충제 thiodicarb의 단감 중 잔류분석 및 안전성 평가

살충제 thiodicarb의 단감 중 안전사용기준 설정과 안전성을 평가를 위하여 처리구별 단감 중 thiodicarb의 잔류량을 GLC/NPD로 분석한 결과, thiodicarb의 가수분해 산물인 methomyl oxime의 최소검출량은 0.2 ng이었으며, thiodicarb의 검출한계는 0.05 ppm 이었다. Thiodicarb의 평균 회수율은 0.5 ppm과 2.5 ppm 수준에서 각각 $93.9{\pm}3.9%$와 $92.8{\pm}2.0%$이었다. 각 처리별 평균 잔류량은 수확전 2회 살포시 $1.50{\pm}0.04$ ppm, 수확전 3회 살포시 $1.86{\pm}0.04$ ppm, 수확전 4회 살포시 $2.11{\pm}0.12$ ppm으로 처리구 모두 thiodicarb의 국내 잠정 잔류허용량(maximum residue limit)인 5 mg/kg 미만이었으며, 단감의 감꼭지나방 방제를 위하여 thiodicarb 40% 수화제를 수확 14일전 4회 살포시 안전성에는 문제가 없을 것으로 판단되었다.