Automated multi-residue isolation of fluoroquinolone antimicrobials from fortified and incurred chicken liver using on-line microdialysis and high-performance liquid chromatography with programmable fluorescence detection

Isolation of the quinolones, sarafloxacin (SAR), oxolinic acid (OXA), and flumequine (FMQ), from fortified chicken liver tissues, and SAR incurred chicken Liver tissues was achieved by combined liquid-liquid extraction and aqueous on-line microdialysis using the automated trace enrichment of dialysates (ASTED) system. Analysis of tissue isolates after ASTED clean-up was performed using reversed-phase HPLC and programmable fluorescence detection. Overall recoveries of SAR, OXA and FMQ from samples fortified over a concentrations range of 1-100 ppb were 94, 97 and 87% with overall inter-assay variability of 4.2, 4.1 and 3.6%, respectively. Chicken liver samples incurred with SAR at three concentration levels also were tested by the ASTED method. The method exhibited high peak resolution (3.4-4.2 on average), a high signal-to-noise ratio, and demonstrated good precision. The ASTED-HPLC method overall had a lower limit of detection (LOD) of 0.2 ppb, and a Limit of quantitation (LOQ) of 1 ppb. (C) 1999 Elsevier Science B.V. All rights reserved.