Simultaneous determination of 13 quinolones from feeds using accelerated solvent extraction and liquid chromatography

A simple multi-residue method is described for assaying 13 quinolones (QNs; pipemidic acid, rufloxacin, enoxacin, ofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, difloxacin, cinoxacin, oxolinic acid, nalidixic acid and flumequine) in feeds. The samples were extracted by a metaphosphoric acid/acetonitrile mixture at pH 2.6 (ASE 200) and automatically purified onto OASIS HLB cartridges (ASPEC XL). The determination was achieved by liquid chromatography (LC) using a C-5 analytical column (150 x 4.6 mm, 5 mum) either with photodiode-array or fluorescence detection. The procedure was validated by spiking a feed sample at three different levels (5, 10 and 25 mg kg(-1)) and linearity, detection limit, quantification limit, accuracy and precision were checked. The automated preparation of the sample permits a very fast analysis which is an important goal for routine purposes. (C) 2002 Elsevier Science B.V. All rights reserved.