Analysis of kresoxim-methyl and its thermolabile metabolites in Korean plum: An application of pepper leaf matrix as a protectant for GC amenable metabolites

• Published in: Journal of separation science Vol. 36; no. 1; pp. 203 - 211
• Main Authors: Rahman, Md. Musfiqur, Park, Jong-Hyouk, Abd El-Aty, A. M., Choi, Jeong-Heui, Cho, Soon-Kil, Yang, Angel, Park, Ki Hun, Shim, Jae-Han
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.01.2013; Wiley; Wiley Subscription Services, Inc
• Subjects: Biological and medical sciences; Calibration; Capsicum - chemistry; Cartridges; Chromatography; Chromatography, Gas; Elution; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; GC-electron capture detector; Korea; Korean plum; Kresoxim-methyl; Leaf matrix; Metabolites; Methacrylates - analysis; Methacrylates - metabolism; Parents; Peppers; Phenylacetates - analysis; Phenylacetates - metabolism; Plant Leaves - chemistry; Plums; Prunus - chemistry; Residues; Strobilurins; Temperature; Thermolabile metabolites; Solid phase extraction; Korean plum; Chemical analysis; Metabolite; Strobilurin; Solvent extraction; Thermolabile metabolites; Chemical enrichment; Plum; Sample preparation; Dicotyledones; Angiospermae; Kresoxim-methyl; Protection; Quantitative analysis; Validation; GC-electron capture detector; Electron capture detector; Fruit; Pesticides; Piperaceae; Plant leaf; Contamination; Fungicide; Gas chromatography; Residue; Spermatophyta; Leaf matrix; Piper
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.201200618

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 (r2) ≥ 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.