Analysis of flumequine and oxolinic acid in edible animal tissues by LC with fluorimetric detection

A simple rapid method has been developed for the determination of flumequine and oxolinic acid in edible animal tissues. Analytes are extracted from the sample matrix using dichloromethane in neutral conditions, then back-extracted in 0.01 M sodium hydroxide and determined by reversed-phase liquid chromotography with fluorimetric detection. The method has been applied to pork, salmon and chicken muscle with recoveries higher than 77% in all matrices. The detection limits achieved (< 1 mu g kg(-1)) allow the determination of these drugs at a residue level far below their MRL Moreover, some variables that may affect the spiking process have been studied.