Abstract
An analytical method for detecting metamifop residue in paddy water, soil, and rice with high performance liquid chromatography (HPLC) was developed. Water was extracted with ethyl acetate before analyzing by HPLC. Soil residues were extracted with acetone under acidic condition and after purifying with $Extrelut^{(R)}$ NT, and silica SPE, the residue was analyzed by HPLC. For residue analysis in rice, the procedure involved extraction with acetone, purification with $Extrelut^{(R)}$ NT, partitioning between acetonitrile/hexane, purification with silica SPE cartridge, and analysis by HPLC. The limit of detection (LOD) was 1.0 ng, limit of quantitation (LOQ) was 3.0 ng, and method limit of quantitation (MLOQ) were 0.001 mg/L for paddy water, 0.01 mg/kg for rice and soil, respectively. Standard calibration curve shows linearity from 0.05 mg/kg to 5.0 mg/kg ($R^2=0.9999$). The recoveries in fortified paddy water were $91.3{\pm}3.5%$ (0.01 mg/L level) and $93.2{\pm}6.3%$ (0.05 mg/L level). The recoveries in fortified paddy soils were $92.5{\pm}4.0%$ (0.1 mg/kg level) and $92.7{\pm}4.0%$ (0.5 mg/kg level) in soil A, while, $102.3{\pm}4.4%$ (0.1 mg/kg level) and $98.9{\pm}7.9%$ (0.5 mg/kg level) in soil B, respectively. The recoveries in fortified rice were $93.0{\pm}6.9%$ (0.1 mg/kg level) and $85.0{\pm}3.5%$ (0.5 mg/kg level). This method was proved to be effective and can be used to determine the metamifop residue in paddy water, paddy soil, and rice.
고성능 액체크로마토그래프(HPLC)를 이용한 농업용수, 논토양, 현미 중 잔류 metamifop을 분석하기 위한 최적화한 추출법과 정제법을 조합하여 분석법을 개발하였다. 농업용수 중 잔류량은 ethyl acetate로 분배 추출, 논토양 중 잔류량은 아세톤으로 추출하고, $Extrelut^{(R)}$ NT 흡착 정제 후 실리카 SPE로 정제하여 HPLC로 분석하였다. 현미 중 잔류량은 아세톤으로 추출하고, $Extrelut^{(R)}$ NT 흡착 정제과정과 acetonitrile/hexane 분배 후 실리카 SPE로 정제하여 HPLC로 분석하였다. 확립된 분석법의 검출 한계(limit of detection, LOD)는 1.0 ng이었고, 시료의 양을 고려한 방법정량한계(method limit of quantitation, MLOQ)는 농업용수, 논토양과 현미 각각 0.001 mg/L, 0.01 mg/kg이었다. 표준검량선은 0.05 mg/kg 농도에서 5.0 mg/kg 범위까지 직선성을 보였고 ($R^2=0.9999$), 시료 중 회수율은 0.01, 0.05 mg/L 수준으로 첨가된 농업용수에서 각각 $91.3{\pm}3.5$, $93.2{\pm}6.3%$이었다. 0.1, 0.5 mg/kg 수준으로 첨가한 A토양시료 중 회수율은 각각 $92.5{\pm}4.0$, $92.7{\pm}4.0%$이었고, B토양시료 중 회수율은 $102.3{\pm}4.4$, $98.9{\pm}7.9%$로 확인되었다. 또한, 0.1, 0.5 mg/kg 수준으로 첨가한 현미시료 중 회수율은 각각 $93.0{\pm}6.9$, $85.0{\pm}3.5%$로 확립된 분석법은 농업용수, 논토양, 그리고 현미중 잔류 metamifop의 분석에 적용할 수 있을 것이다.
