High-performance liquid chromatographic determination of oxolinic acid andflumequine in the live fish feed Artemia

A high-performance liquid chromatography (HPLC) analytical method for the d etermination of oxolinic acid and flumequine in Artemia nauplii is describe d. The samples were extracted and cleaned up by a solid-phase extraction (S PE) procedure using SPE C-18 cartridges. Oxolinic acid and flumequine were determined by reversed-phase HPLC using a mobile phase of methanol-0.1 M ph osphate buffer, pH 3 (45:55, v/v) and a UV detection wavelength of 254 nm. Calibration curves were linear for oxolinic acid in the range of 0.2-50 mug /g (r(2)=0.9998) and for flumequine in the range of 0.3-50 mug/g (r(2)=0.99 94). Mean recoveries amounted to 100.8% and 98.4% for oxolinic acid and flu mequine, respectively. The quantification limit was 0.2 mug/g for oxolinic acid and 0.3 mug/g for flumequine. Quantitative data from an in vivo feedin g study indicated excellent uptake of both drugs by Artemia nauplii. (C) 20 01 Elsevier Science B.V. All rights reserved.