title: Selective sample preparation for the analysis of (fluoro)quinolones in baby food: molecularly imprinted polymers versus anion-exchange resins.
abstract: In this work, an analytical method for simultaneous analysis of several quinolones (cinoxacin, oxolinic acid, nalidixic acid, and flumequine) and fluoroquinolones (norfloxacin, enrofloxacin, enoxacin, ciprofloxacin, and danofloxacin) in baby-food samples is described for the first time. The method is based on isolation of these analytes by ultrasound-assisted extraction procedure followed by a solid-phase extraction sample clean-up step and final determination of the analytes by HPLC using UV detection. For the extraction step, 2 g baby food was mixed with methanol in a centrifuge tube and one single extraction cycle of 15 min at room temperature was carried out. After centrifugation, supernatant was collected and two different solid-phase extraction procedures were developed and evaluated for sample clean-up. The first was based on use of strong anion-exchange cartridges whereas the second was based on use of a ciprofloxacin-imprinted polymer. Both sample clean-up procedures had their own advantages and drawbacks, and the analytical performance and applicability of each procedure was established and properly discussed. The anion-exchange resin-based method enabled simultaneous determination of quinolones and fluoroquinolones, reaching limits of detection ranging from 0.03 to 0.11 microg g(-1). In contrast, the use of a ciprofloxacin-imprinted polymer did provide selectivity towards fluoroquinolones, leading to chromatograms free from co-extractives reaching limits of detection one order of magnitude lower than those obtained by the first approach.
authors.affiliation: Departamento de Medio Ambiente, INIA, Crta. A Coruña Km. 7, 28040, Madrid, Spain.
authors.forename: Myriam
authors.initials: M
authors.lastname: Díaz-Alvarez
authors.forename: Esther
authors.initials: E
authors.lastname: Turiel
authors.forename: Antonio
authors.initials: A
authors.lastname: Martín-Esteban
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D000837:Anion Exchange Resins / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis / Q000379:methods*; D007225:Infant Food / Q000032:analysis*; D054802:Molecular Imprinting / Q000379:methods*; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D015363:Quinolones / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D000837:Anion Exchange Resins; D011108:Polymers; D015363:Quinolones