시료 중 잔류 항생제 분석 방법: II. 액상 시료 전처리 방법

Korea is one of the countries with a large market of veterinary antibiotics, although antimicrobial resistance in bacteria is becoming a serious issue in many countries. Korean government started to be interested in estimation of effects of livestock manure on rivers and agricultural soils and in monitoring heavy metals, organic pollutants and antibiotics in the water and soil samples. In this paper, pre-treatment methods to separate the selected antibiotics from the solid samples were reviewed. It is essential to select an efficient and proper procedure for the pre-treatment due to the high portion of proteins and organics in biosolid samples. The pre-treatment consists of extraction followed by clean-up. Initially, homogenized samples were extracted by sonication, mechanical agitation or pressurized liquid extraction with methanol/acetonitrile/water mixture under acidic/base depending on compounds. However, aminoglycosides and colistin were extracted with 5% trichloroacetic acid and HCl, respectively. Since the β-lactams are easily decomposed in acidic and basic condition, these were extracted in neutral pH. Filtration with membrane (pore size, 0.2 μm) or solid phase extraction with HLB and methanol, as eluent, were normally applied for the clean-up. More than three pre-treatment procedures should be adopted to screen all the selected antibiotics in solid samples.