Determination of Quinolone Antibiotics in Bovine Liver Using Agilent Bond Elut QuEChERS Kits by LC/MS/MS

This paper presents an analytical method which allows the determination of 11 quinolone antibiotic residue in bovine liver: pipemidic acid, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin, sarafloxacin, cinoxacin, oxolinic acid, nalidixic acid, and flumequine. The procedure involves a rapid and efficient pretreatment by Bond Elut QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous, 5% formic acid acetonitrile system. An extraction and partitioning step was performed after the addition of salts. Cleanup was done using dispersive solid phase extraction (dispersive-SPE). The final extracts allowed determination of all compounds in a single run using LC-ESI-MS-MS operating in positive ion multiple reaction monitoring (MRM) mode. Norfloxacin was selected as the internal standard. The accuracy of the method, expressed as recovery, was between 62 and 113%. The precision, expressed as RSD, was between 2.2 and 13.4%. The established limit of quantification (LOQ) was 5 ng/g and is significantly lower than the respective Maximum Residue Limit (MRL) for quinolones in food producing animals. Author Limian Zhao, and Joan Stevens Agilent Technologies, Inc. 2850 Centerville Road Wilmington, DE 19808 USA Application Note