title: Development of an extraction method for the determination of avermectins in soil using supercritical CO2 modified with ethanol and liquid chromatography-tandem mass spectrometry.
abstract: The aim of the present study was to develop a multiresidue analytical method for determination of avermectins (abamectin, ivermectin, moxidectin, and doramectin) in soil samples using supercritical fluid extraction and LC-MS/MS. The optimal extraction conditions for supercritical fluid extraction were 80°C for temperature, 300 kg/cm(2)  for pressure, 40 min as an extraction time, and 30% of a modifier ratio. The linearity of the calibration curves was excellent and yielded the correlation coefficients (r(2)  = 0.998-0.999, at a range of 1.5-500 ng/g). Soil samples were fortified with known quantities of the analytes at three different concentration levels (5, 10, and 50 ng/g) and the recoveries were in the range of 82.5-96.2% with relative standard deviation values ranging between 2.1 and 7.9%. The limits of detections and limits of quantitations were 1.5 and 5 ng/g, respectively. The developed method was successfully applied to analyze avermectin residues in soil samples collected from 13 sites in the Honam area, Republic of Korea. In sum, a combination of supercritical fluid extraction and LC-MS/MS has been proven to be highly efficient as an environmentally friendly technique for the simultaneous determination of avermectins in soil samples.
authors.affiliation: Natural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, Yongbong-ro, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Jong-Hyouk
authors.initials: JH
authors.lastname: Park
authors.forename: Jeong-Heui
authors.initials: JH
authors.lastname: Choi
authors.forename: A M
authors.initials: AM
authors.lastname: Abd El-Aty
authors.forename: Joon-Seong
authors.initials: JS
authors.lastname: Park
authors.forename: Bo Mi
authors.initials: BM
authors.lastname: Kim
authors.forename: Tae-Woong
authors.initials: TW
authors.lastname: Na
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
authors.forename: Angel
authors.initials: A
authors.lastname: Yang
authors.forename: Md Musfiqur
authors.initials: MM
authors.lastname: Rahman
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Shim
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002853:Chromatography, Liquid; D000431:Ethanol / Q000737:chemistry*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D000431:Ethanol; D007559:Ivermectin; C019264:avermectin