title: Simple models for the effect of aliphatic alcohol additives on the retention in reversed-phase liquid chromatography.
abstract: Four retention models for the effect of aliphatic alcohol additives on the retention of analytes in reversed-phase liquid chromatography have been developed following either a semi-thermodynamic treatment or an empirical approach. Their performance was tested using the experimental retention times of six non-polar analytes (alkylbenzenes) and ten o-phthalaldehyde derivatives of amino acids under different isocratic chromatographic runs when a small amount of ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol or 1-heptanol was added to methanol/water mixtures containing a constant amount of methanol. It was shown that for the structurally simple alkylbenzenes all the models can be adopted for retention prediction with good results. In contrast, just one out of four models, that with the fewest approximations, predicts satisfactorily the retention properties of amino acids derivatives. However, the most interesting feature is that this model can predict the effect of an alcohol-additive on the retention properties of solutes, even if this additive was not used in chromatographic runs done for the fitting procedure, provided that it belongs to the same homologous series of alkanols. This feature is also observed in all models described the retention of alkylbenzenes.
authors.affiliation: Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: P
authors.initials: P
authors.lastname: Nikitas
authors.forename: A
authors.initials: A
authors.lastname: Pappa-Louisi
authors.forename: P
authors.initials: P
authors.lastname: Agrafiotou
authors.forename: S
authors.initials: S
authors.lastname: Fasoula
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D000465:Algorithms; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D001555:Benzene Derivatives / Q000737:chemistry; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D003627:Data Interpretation, Statistical; D008956:Models, Chemical; D008968:Molecular Conformation; D013816:Thermodynamics
chemical_list: D000438:Alcohols; D000596:Amino Acids; D001555:Benzene Derivatives