Fast-scanning fluorescence spectroscopy as a detection system in liquid chromatography for confirmatory analysis of flumequine and oxolinic acid

Oxolinic acid and flumequine were analysed by reversed-phase liquid chromatography after extraction from the sample matrix with dichloromethane and partitioning with NaOH. The detection system consisted of a fast-scanning fluorescence detector, which provides the full spectra of the eluting peaks and can thus be used to confirm the identity of analytes. Determination was performed by partial least squares (PLS) and three-way PLS over the three-dimensional data, i.e. fluorescence intensity versus retention time and excitation wavelength. In both cases, similar results, with prediction errors around 4%, were obtained. The method was successfully applied to the analysis of salmon, pork and chicken muscle spiked up to 300 ng g−1.