title: Oxidized multi-walled carbon nanotubes for the dispersive solid-phase extraction of quinolone antibiotics from water samples using capillary electrophoresis and large volume sample stacking with polarity switching.
abstract: In this work, a new method for the determination of eleven quinolone antibiotics (moxifloxacin, lomefloxacin, danofloxacin, ciprofloxacin, levofloxacin, marbofloxacin, enrofloxacin, difloxacin, pefloxacin, oxolinic acid and flumequine) in different water samples using dispersive solid-phase extraction (dSPE) and capillary zone electrophoresis with diode-array detection was developed. Oxidized multi-walled carbon nanotubes (o-MWCNTs) were used for the first time as stationary phases for the off-line preconcentration by dSPE of the antibiotics. A 65 mM phosphate buffer at pH 8.5 was found adequate for analyte separation while large volume sample stacking with polarity switching of the analytes dissolved in water containing 10% (v/v) of acetonitrile was carried out in order to improve the sensitivity. dSPE parameters, such as sample volume and pH, o-MWCNT amount, volume and type of eluent in dSPE were optimized. Application of the developed method to the analysis of spiked Milli-Q, mineral, tap, and wastewater samples resulted in good recoveries values ranging from 62.3 to 116% with relative standard deviation values lower than 7.7% in all cases. Limits of detection were in the range of 28-94 ng/L. The proposed method is very fast, simple, repeatable, accurate and highly selective.
authors: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez, s/n°, 38206 La Laguna (Tenerife), Spain.
authors: Antonio V
authors: AV
authors: Herrera-Herrera
authors: Lidia M
authors: LM
authors: Ravelo-Pérez
authors: Javier
authors: J
authors: Hernández-Borges
authors: María M
authors: MM
authors: Afonso
authors: J Antonio
authors: JA
authors: Palenzuela
authors: Miguel Ángel
authors: MÁ
authors: Rodríguez-Delgado
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D015363:Quinolones / Q000032:analysis* / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D037742:Nanotubes, Carbon; D015363:Quinolones; D014874:Water Pollutants, Chemical