Establishment of Pre-Harvest Residue Limit (PHRL) of Methoxyfenozide and Novaluron on Peaches

Methoxyfenozide and novaluron were sprayed with single and triple treatments separately on peach during cultivation period. Samples were collected over 14 days, 8 times in total (0, 2, 4, 6, 8, 10, 12, 14 days). Methoxyfenozide and novaluron were extracted with acetone and partitioned with dichloromethane, and analyzed by HPLC/DAD. Method Quantitation Limit (MQL) were both 0.005 mg/kg, average recoveries of methoxyfenozide at two fortification levels of 0.05 and 0.25 mg/kg were determined $92.7{\pm}2.9%$ and $102.8{\pm}3.1%$, and novaluron were $98.2{\pm}4.8%$ and $96.7{\pm}9.0%$, respectively. The biological half-life of methoxyfenozide was about 4.41 days at single treatment, and 4.24 days at triple treatments. The biological half-life of novaluron was about 14.81 days at single treatment, and 14.50 days at triple treatments. Dissipation of pesticides on peach was influenced by growth dilution effect. In case of application of methoxyfenozide and novaluron following guidelines on safe use of pesticides, the final residue level was predicted to be lower than Maximum Residue Limit (MRL).

복숭아 중 Methoxyfenozide와 Novaluron의 생산단계 농약잔류허용기준 설정

복숭아 재배 중 methoxyfenozide와 novalruon을 1회 처리와 3회 처리로 구분하여 살포하고, 살포 후 0, 2, 4, 6, 8, 10, 12, 14일까지 복숭아 시료를 채취하였다. Methoxyfenozide와 novaluron은 acetone으로 추출, dichloromethane으로 분배하여 HPLC/DAD로 분석하였다. 분석결과 정량분석한계는 모두 0.005 mg/kg이었고, 0.05 및 0.25 mg/kg 수준에서 methoxyfenozide의 평균 회수율은 각각 $92.7{\pm}2.9%$와 $102.8{\pm}3.1%$, novaluron은 $98.2{\pm}4.8%$와 $96.7{\pm}9.0%$이었다. 복숭아에서 methoxyfenozide의 생물학적 반감기는 4.41일(1회)과 4.24일(3회)이었고, novaluron은 14.81일(1회)과 14.50일(3회)이었으며, 복숭아의 증체율에 따른 희석효과가 잔류량 감소에 영향을 주었으며, methoxyfenozide와 novaluron을 농약안전사용기준에 따라 처리 시 최종잔류농도는 MRL 이하로 떨어질 것으로 예측된다.