title: Temperature effects on separation on zirconia columns: applications to one- and two-dimensional LC separations of phenolic antioxidants.
abstract: The effects of temperature and mobile phase on LC chromatographic separation of phenolic antioxidants on zirconia-based columns were investigated. Unlike silica-based materials, zirconia columns show excellent thermal stability over a wide range of temperatures and enable high-temperature separations. Enthalpic and entropic contributions to the retention of phenolic compounds on ZR-Carbon and ZR-Carbon C18 columns were determined from retention versus temperature plots in order to elucidate the retention mechanism of sample compounds over the temperature range up to 14 degrees C. High-temperature liquid chromatography on ZR-Carbon columns was used for comprehensive LC x LC two-dimensional separation systems based on the different selectivity of a Zorbax SB micro-column used in the first dimension and a ZR-Carbon column used in the second dimension. Two-dimensional LC x LC systems employing a setup with two alternately operated parallel ZR-Carbon columns in the second dimension were used for the analysis of phenolic antioxidants in beer and wine samples.
authors: Department of Analytical Chemistry, University of Pardubice, Pardubice, Czech Republic.
authors: Francesco
authors: F
authors: Cacciola
authors: Pavel
authors: P
authors: Jandera
authors: Luigi
authors: L
authors: Mondello
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000302:isolation & purification*; D002244:Carbon; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods*; D005419:Flavonoids / Q000032:analysis / Q000302:isolation & purification; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification*; D013696:Temperature; D015040:Zirconium
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D002244:Carbon; D015040:Zirconium; C028541:zirconium oxide