New near ultraviolet laser-induced native fluorescence detection coupled to HPLC to analyse residues of oxolinic acid and flumequinea comparison with conventional xenon flash lamp
- Feás Sánchez, Xesús
- Fente Sampayo, Cristina A.
- Hosseini, S.V.
- Cepeda, A.
ISSN: 1947-6337, 1947-6345
Ano de publicación: 2009
Volume: 7
Número: 1
Páxinas: 15-21
Tipo: Artigo
Outras publicacións en: CyTA: Journal of food
Resumo
A new high-performance liquid chromatography (HPLC) method is described for the determination of oxolinic acid and flumequine, with ultraviolet laser-induced fluorescence detection (UV-LIFD). Near-UV excitation at 325 nm was obtained by using an He/Cd laser. Data obtained using UV-LIFD and conventional fluorimetry (Xenon flash, ?exc 325/ ?em 365) are compared under the same chromatographic conditions, connecting in series both detectors, in terms of linearity, reproducibility and repeatability. The HPLC separation is carried out on a Synergi MAX-RP column with water-acetonitrile (2:1, v/v) adjusted at pH 2.5, with formic acid, as mobile phase and completed in less than 9 min. The detection limits of oxolinic acid and flumequine at a signal-to-noise ratio of 3 were 0.43 pg and 0.76 pg on column with UV-LIFD detection, making this method considerably more sensitive than traditional fluorescence detector (16.15 pg and 14.17 pg) having some obvious advantages.