초록
본 연구는 포도에 대한 pyrimethanil과 methoxyfenozide의 잔류량 변화를 측정하여 약제별 잔류특성을 파악하고, 잔류량 감소추이를 산출함으로써 생산단계 잔류허용기준(Pre-Harvest Residue Limit, PHRL) 설정을 위한 기초자료로 활용하고자 수행하였다. Pyrimethanil 및 methoxyfenozide 농약을 안전사용기준에 준하여 각각 포장 1, 포장 2 지역으로 나누어 기준량 처리하였으며, 약제처리 2시간 후를 0일차로 하여 0, 1, 2, 3, 5, 7, 10일차에 시료를 채취하여 분석하였다. 두 약제 모두 HPLC/DAD를 이용하여 분석하였으며, 분석정량한계(Method Limit of Quantitation, MLOQ)는 $0.01mg\;kg^{-1}$이었다. 분석결과, 분석법의 회수율은 80.6~102.5%이었으며, 표준편차는 모두 10% 미만이었다. 포도 중 각 농약에 대한 생물학적 반감기는 pyrimethanil의 경우 7.7일(포장 1), 7.4일(포장 2)이었으며, methoxyfenozide의 경우 5.1일(포장 1), 6.1일(포장 2)이었다. 잔류회귀감소식을 이용한 pyrimethanil과 methoxyfenozide의 생산단계 잔류허용기준은 각각 수확 10일 전 8.90과 $5.51mg\;kg^{-1}$으로 제안하였다.
The present study was aimed to predict the pre-harvest residue limits (PHRLs) of pyrimethanil (fungicide) and methoxyfenozide (insecticide) in grape, and to estimate their biological half-lives and residual characteristics. The pesticides were sprayed once on grape in two different fields 10 days before harvest. At the end of 0, 1, 2, 3, 5, 7 and 10 days after application, samples were harvested for further analysis. The residual pesticides were extracted with acetonitrile and partitioned with dichloromethane, and the high-performance liquid chromatography with diode array detector (HPLC/DAD) was employed for the residue analysis. The results obtained in the present study show that the limit of detection of both pesticides were found to be $0.01mg\;kg^{-1}$. The recoveries of these pesticides were ranged between 80.6% and 102.5% with coefficient of variation lower than 10%. The biological half-lives of both pesticides were observed in field 1 and field 2 which shows 7.7 and 7.4 days for pyrimethanil and 5.1 and 6.1 days for methoxyfenozide, respectively. Further, the PHRL of pyrimethanil and methoxyfenozide was found to be $8.90mg\;kg^{-1}$ and $5.51mg\;kg^{-1}$, respectively at 10 days before harvest. Consequently, the present study suggests that the residual amounts of both pesticides will be lower than the maximum residue limits (MRLs) when grape is harvested.
