title: Preconcentration of quinolones by dialysis on-line coupled to high-performance liquid chromatography.
abstract: The parameters influencing dialytic separation of ciprofloxacin (CF) fluoroquinolone were investigated. Dialysis with a porous cellulose acetate membrane was on-line coupled with HPLC and the analysis of dialysate was made by isocratic ion-pairing liquid chromatography using a reversed-phase analytical column and fluorescence detection. Optimisation of the experimental conditions for selective dialytic enrichment are described and explanations of some phenomena affecting dialysis efficiency discussed. By the use of a neutral donor (pH approximately 7) and acidic acceptor solution (pH < 4) a substantial enrichment of quinolones was achieved. Accumulation of CF in the acidic acceptor phase is based on the protonation of the analyte in the acceptor compartment. Continuous-flow of donor solution and a stagnant acceptor solution gave high dialysis efficiency in 5-15 min. Effects of interfering substances present in real samples on the variation of dialysis efficiency can be minimised by successive dialysis runs of the original and spiked samples.
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia.
authors.forename: T
authors.initials: T
authors.lastname: Zupancic
authors.forename: B
authors.initials: B
authors.lastname: Pihlar
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002939:Ciprofloxacin / Q000302:isolation & purification*; D003956:Dialysis; D006863:Hydrogen-Ion Concentration; D012680:Sensitivity and Specificity; D012996:Solutions; D013997:Time Factors; D014867:Water
chemical_list: D012996:Solutions; D014867:Water; C005062:acetylcellulose; D002939:Ciprofloxacin; D002482:Cellulose