title: Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography.
abstract: Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.
authors.affiliation: Department of Drug Analysis, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000, Belgrade, Serbia.
authors.forename: Marko
authors.initials: M
authors.lastname: Jovanović
authors.forename: Tijana
authors.initials: T
authors.lastname: Rakić
authors.forename: Biljana
authors.initials: B
authors.lastname: Jančić-Stojanović
authors.forename: Darko
authors.initials: D
authors.lastname: Ivanović
authors.forename: Mirjana
authors.initials: M
authors.lastname: Medenica
mesh_terms: D000327:Adsorption; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D007472:Iohexol / Q000737:chemistry*; D015394:Molecular Structure; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D007472:Iohexol; D012822:Silicon Dioxide