Abstract
BACKGROUND: This study was performed to investigate pre-harvest residue limit (PHRL) in Chwinamul, to estimate biological half-life for residue of each pesticide. Chwinamul was sprayed with pesticides of standard and double application rate. Chlorfenapyr and fenarimol were sprayed once on Chwinamul at 10 days before harvest, and it was sampled 7 times and analysed the residual change of two pesticides. METHODS AND RESULTS: Chwinamul sample was extracted with acetonitrile and partitioned with dichloromethane, and pesticide residues were determined with GCECD. Method quantitation limit (MQL) of chlorfenapyr was 0.10 mg/kg and that of fenarimol was 0.02 mg/kg. Recoveries of chlorfenapyr at two fortification levels of 1.0 and 5.0 mg/kg were $94.2{\pm}$1.70 and $99.0{\pm}1.61%$, respectively. Recoveries of fenarimol at two fortification levels of 0.2 and 1.0 mg/kg were $92.1{\pm}2.14$ and $83.1{\pm}1.98%$, respectively. CONCLUSION(s): The biological half-lives of chlorfenapyr were about 3.5 days at standard application rate, and 3.4 days at double application rate. The biological half-lives of fenarimol were about 6.0 days at standard application rate, and 5.9 days at double application rate. The PHRLs of chlorfenapyr were recommended as 13.02 and 6.25 mg/kg for 10 and 5 days before harvest, respectively. And the PHRLs of fenarimol were recommended as 2.80 and 1.67 mg/kg for 10 and 5 days before harvest, respectively.
본 연구는 취나물 재배 중 chlorfenapyr와 fenarimol을 살포 후 0, 1, 2, 3, 5, 7, 10일에 취나물 시료를 채취하고 각각의 농약을 분석하고 그것의 생물학적 반감기를 산출한 다음에 생산단계 농약 잔류허용기준(PHRLs)을 설정하였다. 취나물 중 chlorfenapyr와 fenarimol은 acetonitrile과 dichloromethane으로 추출과 분배를 거쳐 GC-ECD를 이용하여 분석하였다. Chlorfenapyr와 fenarimol의 정량분석한계(MQL)은 chlorfenapyr는 0.10 mg/kg이었고, fenarimol은 0.02 mg/kg이었다. 그리고 chlorfenapyr의 회수율은 1.0과 5.0 mg/kg의 두 처리수준에서 각각 $94.2{\pm}1.70%$과 $99.0{\pm}1.61%$이었다. Fenarimol의 회수율은 0.2과 1.0 mg/kg에서 각각 $92.1{\pm}2.14%$과 $83.1{\pm}1.98%$이었다. 취나물에서 chlorfenapyr의 생물학적 반감기는 기준량 살포시 3.5일, 배량 살포시에는 3.4일이었다. Fenarimol의 생물학적 반감기는 기준량 살포시 6.0일, 배량 살포시에는 5.9일이었다. 잔류감소 회귀식을 이용하여 계산한 생산단계 농약 잔류허용기준(PHRLs)은 chlorfenapyr가 각각 수확 10일전 13.02 mg/kg이었고, 수확 5일 전에는 6.25 mg/kg으로 제안하였다. 그리고 fenarimol은 각각 수확 10일전에 2.80 mg/kg으로, 수확 5일전에는 1.67 mg/kg으로 제안하였다.
