title: Determination of kresoxim-methyl and its thermolabile metabolites in pear utilizing pepper leaf matrix as a protectant using gas chromatography.
abstract: Kresoxim-methyl and its two thermolabile metabolites, BF 490-2 and BF 490-9, were analyzed in pear using a pepper leaf matrix protection to maintain the metabolites inside the gas chromatography system. Samples were extracted with a mixture of ethyl acetate and n-hexane (1:1, v/v) and purified and/or separated using a solid phase extraction procedure. The pepper leaf matrix was added and optimized with cleaned pear extract to enhance metabolite sensitivity. Matrix matched calibration was used for kresoxim-methyl in the pear matrix and for metabolites in the pear mixed with pepper leaf matrix. Good linearity was obtained for all analytes with a coefficient of determination, r (2) ⩾ 0.992. Limits of detection (LOD) and quantification (LOQ) were 0.006 and 0.02 mg kg(-1) and 0.02 and 0.065 mg kg(-1) for kresoxim-methyl and the metabolites, respectively. Recoveries were carried out at two concentration levels and were 85.6-97.9% with a relative standard deviation <2.5%. The method was successfully applied to field incurred pear samples, and only kresoxim-methyl was detected at a concentration of 0.03 mg kg(-1).
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Md Musfiqur
authors: MM
authors: Rahman
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Jin
authors: J
authors: Jang
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Jong-Hyouk
authors: JH
authors: Park
authors: Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt.
authors: A M
authors: AM
authors: Abd El-Aty
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Ah-Young
authors: AY
authors: Ko
authors: Institute of Environmental Research, Faculty of Chemistry, Dortmund University of Technology, 44227 Dortmund, Germany.
authors: Jeong-Heui
authors: JH
authors: Choi
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Angel
authors: A
authors: Yang
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Ki Hun
authors: KH
authors: Park
authors: Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors: Jae-Han
authors: JH
authors: Shim
keywords: Gas chromatography; Kresoxim-methyl; Matrix effect; Metabolites; Pear