title: Analysis of kresoxim-methyl and its thermolabile metabolites in Korean plum: An application of pepper leaf matrix as a protectant for GC amenable metabolites.
abstract: A new method was developed for kresoxim-methyl (parent compound) and its two thermolabile metabolites, BF 490-2 and BF 490-9, in Korean plum, introducing pepper leaf matrix as a natural analyte protectant for GC-amenable metabolites using a GC-electron capture detector. Samples were extracted with a simple and rapid method using a mixture of ethyl acetate-n-hexane (1:1) and salts, and purified via SPE. Due to the elution gap between parent compound and metabolites in the SPE cartridge and matrix interference, kresoxim-methyl was isolated separately from its metabolites. An optimized amount of pepper leaf matrix (0.25 g/mL) was added to the metabolites prior to each injection. Calibration curves were linear over the concentration ranges with coefficient of determination (r(2)) ≥ 0.999. The method was validated in triplicate at two fortification levels, giving recoveries ranging between 74.3 and 101.4%, and RSDs less than 5%. The LOD and LOQ were 0.015 and 0.05 mg/kg, respectively. The method was successfully applied to real samples where kresoxim-methyl residues were detected in field-incurred plum samples. Residues were confirmed using GC-MS.
authors.affiliation: Natural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Md Musfiqur
authors.initials: MM
authors.lastname: Rahman
authors.forename: Jong-Hyouk
authors.initials: JH
authors.lastname: Park
authors.forename: A M
authors.initials: AM
authors.lastname: Abd El-Aty
authors.forename: Jeong-Heui
authors.initials: JH
authors.lastname: Choi
authors.forename: Soon-Kil
authors.initials: SK
authors.lastname: Cho
authors.forename: Angel
authors.initials: A
authors.lastname: Yang
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Shim
mesh_terms: D002212:Capsicum / Q000737:chemistry*; D002849:Chromatography, Gas; D007723:Korea; D008689:Methacrylates / Q000032:analysis / Q000378:metabolism; D010648:Phenylacetates / Q000032:analysis* / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry*; D027861:Prunus / Q000737:chemistry*; D000073739:Strobilurins; D013696:Temperature
chemical_list: D008689:Methacrylates; D010648:Phenylacetates; D000073739:Strobilurins; C469328:kresoxim-methyl