title: Phenylboronic Acid Solid Phase Extraction Cleanup and Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry for the Determination of Florfenicol Amine in Fish Muscles.
abstract: Florfenicol (FFC) residues in foods are regulated as the sum of florfenicol and its metabolites measured as florfenicol amine (FFA). An isotope dilution LC-MS/MS method utilizing phenylboronic acid (PBA) SPE cleanup is established for the accurate determination of FFA in fish muscles (i.e., salmon and tilapia) after acid catalyzed hydrolysis. Comparisons of the PBA SPE cleanup procedure with other cleanup procedures such as mixed-mode cationic (MCX) SPE and solid supported liquid-liquid extraction were performed. Quantification of FFA in fish muscles was accomplished by using matrix-matched calibration with FFA-D3 as the internal standard. The method was validated with FFA fortified fish muscles at three different levels (50, 100, and 200 μg/kg). Conversion of FFC to FFA by acid catalyzed hydrolysis was evaluated and found to be ≥88%. The recoveries of FFA in fish muscles at the three fortification levels ranged from 89 to 106%, and RSDs were ≤9% in all cases. The LOD values in salmon and tilapia muscles were 0.13 and 1.64 μg/kg, respectively. The LOQ values in salmon and tilapia muscles were 0.29 and 4.13 μg/kg, respectively. This method is suitable for the application in routine control of FFC in fishes according to its residue definition.
authors.affiliation: Analytical and Advisory Services Division, Government Laboratory, 7/F, Ho Man Tin Government Offices, 88 Chung Hau St, Ho Man Tin, Kowloon, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Della Wai-Mei
authors.initials: DW
authors.lastname: Sin
authors.forename: Clare
authors.initials: C
authors.lastname: Ho
authors.forename: Yiu-Tung
authors.initials: YT
authors.lastname: Wong
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D001897:Boronic Acids / Q000737:chemistry*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues / Q000032:analysis; D005399:Fishes / Q000378:metabolism*; D005504:Food Analysis; D057230:Limit of Detection; D009132:Muscles / Q000737:chemistry*; D011865:Radioisotope Dilution Technique; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D013839:Thiamphenicol / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D001897:Boronic Acids; C083312:florfenicol amine; D013839:Thiamphenicol; C010686:benzeneboronic acid