Electromembrane extraction (EME)-an easy, novel and rapid extraction procedure for the HPLC determination of fluoroquinolones in wastewater samples

For the first time, an electromembrane extraction combined with a HPLC procedure using diode array and fluorescence detection has been developed for the determination of seven widely used fluoroquinolones (FQs): marbofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, gatifloxacin and grepafloxacin. The drugs were extracted from acid aqueous sample solutions (pH 5), through a supported liquid membrane consisting of 1-octanol impregnated in the walls of a S6/2 AccurelA (R) polypropylene hollow fiber, to an acid (pH 2) aqueous acceptor solution inside the lumen of the hollow fiber. The main operational parameters were optimized, and extractions were carried out in 15 min using a potential of 50 V. Enrichment factors of 40-85 have been obtained using only 15 min of extraction time versus 330 min used in a previously proposed hollow-fiber liquid-phase microextraction procedure. The procedure allows low detection and quantitation limits of 0.005-0.07 and 0.007-0.15 mu g L-1, respectively. The proposed method was successfully applied to the FQs analysis in urban wastewaters.