DETERMINATION OF FLUMEQUINE AND OXOLINIC ACID IN FORTIFIED CHICKEN TISSUE USING ONLINE DIALYSIS AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

Isolation of the fluoroquinolones, flumequine and oxolinic acid, from fortified chicken liver was achieved using liquid-liquid extraction, a queous on-line dialysis and trace enrichment. Dialysis, trace enrichme nt and column switching were performed using the ASTED system. Separat ion of the isolated compounds in the tissue extracts was performed usi ng reversed-phase HPLC and fluorescence detection. This procedure yiel ded excellent mean recoveries at the 50, 25, 10 and 5 ng/g spiking lev els for flumequine (94-96%; 4-9% R.S.D.) and at the 25 and 5 ng/g spik ing levels for oxolinic acid (98-99%; 4-6% R.S.D.). Clean chromatogram s were obtained, allowing detection of 5 ng/g flumequine and 2.5 ng/g oxolinic acid to be easily made. Due to its lower organic solvent cons umption, automation and on-line capabilities, this method may be a sui table replacement for conventional chemical extraction techniques for drug residues in animal tissues. (C) 1998 Elsevier Science B.V.