Efficiency of Silver Ion-Silica Solid Phase Extraction for Elimination of Sulfur Compounds during Pesticide Multiresidue Analysis in Allium Species

파속류의 잔류농약분석과정에서 silver ion-silica solid phase extraction에 의한 황화합물의 제거 효율성

Since organic sulfur compounds respond to GC/ECD sensitively, they interfere with quantitative separation of pesticides during residual pesticide analysis of Allium species. In this study, it was intended to develop a rapid and simple method for pesticide multi-residues analysis through clean-up and interferences by a solid-phase extraction (SPE). An SPE method employing silver nitrate impregnated Florosil cartridge was developed and evaluated for the elimination of sulfur compounds from the test solution of Allium species during pesticide residues analysis. The silver nitrate impregnated Florosil cartridge was prepared by efflux of 3 ml of 20% silver nitrate solution through Florosil cartridge (1 g packing, 6 ml tube). The extracts equivalent to 2, 4 6, and 10 g of each sample were loaded onto the cartridge and allowed to exude, and then the exudations were analyzed by GC/ECD. More than 95% of sulfur compounds were removed from the loaded extracts equivalent, up to 6 g in onion, 4 g in spring onion and 4 g in shallot, respectively. 40 pesticides were spiked in the Allium species and loaded onto the cartridge to determine the recoveries; from this, the recoveries of 34 pesticides were within 70~120%.

파속류에 다량 함유된 황화합물들은 GC/ECD에 민감하게 반응하기에, 이 농산물들의 잔류농약분석에서 방해 물질로 작용하여 농약성분의 분리정량에 어려움을 주고 있다. 최근 잔류농약분석에서 정제법으로 여러 가지 고상추출법(solid-phase extraction)이 개발되고 있으며, 본 연구에서는 황화합물을 효율적으로 제거하기 위하여, 20% 질산은($AgNO_3$)용액 3 ml을 Florosil cartridge (1 g packing, 6 ml tube)에 처리한 은이온흡착 cartridge (silver nitrate impregnated florosil cartridge)를 조제하였다. 이 cartridge를 이용하여 파속류 각 2, 4, 6 및 10 g에 해당하는 추출액을 고상추출법으로 정제한 결과, 양파 6 g, 대파 4 g, 쪽파는 4 g 까지는 황화합물의 95% 이상을 제거할 수 있었다. 그리고, 40종의 농약을 각 파속류에 첨가하고 이 cartridge에서 유출하여 회수율을 분석한 결과 34종이 70~120%의 범위 안에 들었다.