Abstract
Quintozene, pentachloronitrobenzene (PCNB) is a contact fungicide for control of soilborne phytopathogenic fungi during cultivation of diverse crops. It was introduced to agricultural use around 1930's as a substitute for mercurial disinfectants. Although quintozene had been first registered in Korea on 1969. However, now it was banned to use due to its high residue levels in selected harvest products. Also, high possibility is expected that the residue may be contained in imported agricultural commodities as it is still used widely over the world. Therefore, this study was conducted to establish a determination method for quintozene residue in crops using GC/ECD/MS. Quintozene residue was extracted with acetonitrile from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and n-hexane partition was followed to recover quintozene from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The quintozene was quantitated by GLC with ECD, using a DB-1 capillary column. The crops were fortified with quintozene at 3 levels per crop. Mean recoveries ranged from 79.9% to 102.7% in five representative agricultural commodities. The coefficients of variation were less than 4.3%. Quantitative limit of quintozene was 0.004 mg/kg in representative five crop samples. A GC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of quintozene in agricultural commodities.
본 연구에서는 GC-ECD/MS를 이용하여 농산물 중 aromatic 살균제 quintozene의 잔류 분석법을 확립하였다. 대표 농산물은 사과, 고추, 배추, 현미 및 콩을 선정하였고, acetonitrile을 가하여 추출된 quintozene 성분을 n-hexane 액-액 분배법과 florisil 흡착크로마토그래피법으로 정제하여 GC-ECD/MS 분석대상 시료로 사용하였다. Quintozene의 정량적 분석을 위한 최적 GC-ECD 분석 조건을 확립하였으며, 정량한계(LOQ)는 0.004 mg/kg 이었다. 각 대표 농산물에 대해 정량한계, 정량한계의 10배 및 50배 수준에서 회수율을 검토한 결과 모든 처리농도에서 79.9~102.7% 수준을 나타내었으며, 반복 간 변이계수(CV)는 최대 4.3%를 나타내어 잔류분석 기준인 회수율 70~120% 및 분석오차 10% 이내를 충족시키는 만족한 결과를 도출하였으며, GC/MS/SIM을 이용하여 실제 농산물 시료에 적용하여 재확인 하였다. 이상의 결과로 신규 quintozene의 GC-ECD/MS 분석법은 검출한계, 회수율 및 분석오차면에서 국제적 분석기준을 만족하는 신뢰성이 확보된 정량 분석법으로 사용 가능할 것이다.
