Effect of analyte properties on the kinetic performance of liquid chromatographic separations
Journal of Chromatography A
University of Stellenbosch, Department of Chemistry, Private Bag X1, Matieland, 7602, South Africa; Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281, S4-bis, B-9000 Ghent, Belgium
Advances in modern high-performance liquid chromatography (HPLC) have led to increased interest in the comparison of the ultimate performance limits of methodologies aimed at increasing the resolving power per unit time. Kinetic plot-based methods have proven invaluable in facilitating such evaluations. However, in bridging the gap between fundamental comparisons and the eventual practical applicability of kinetic performance data, the effect of analyte properties have thus far largely been neglected. Using pharmaceutical compounds as representative real-life analytes, it is demonstrated that noteworthy differences in the optimal kinetic performance of a chromatographic system are observed compared to data for common test compounds. For a given stationary phase particle size, higher optimal- and maximum plate numbers, corresponding to increased analysis times, are measured for pharmaceutical compounds. Moreover, it is found that the optimal particle size/maximum pressure combination depends on the analyte under investigation, with the beneficial range of efficiencies for small particles shifted towards higher plate numbers for drug molecules. It is further demonstrated that the pH of the mobile phase plays a crucial role in determining the kinetic performance of pharmaceutical compounds. These data clearly indicate that data for test compounds do not reflect the performance attainable for pharmaceutical compounds and highlights the importance of using real-life samples to perform kinetic evaluations. © 2008 Elsevier B.V. All rights reserved.
Analyte properties; Analytes; Chromatographic systems; Drug molecules; High-performance liquid chromatographies; Kinetic evaluations; Kinetic plots; Liquid chromatographic separations; Mobile phase; Per units; Performance datum; Performance limits; Pharmaceutical compounds; Resolving power; Small particles; Stationary phase; Body fluids; Chromatography; High performance liquid chromatography; High pressure liquid chromatography; Liquids; Optimization; Particle size analysis; Chromatographic analysis; phenol derivative; propyl paraben; analytic method; analytical equipment; article; drug determination; instrumentation; kinetics; liquid chromatography; measurement; particle size; pH; priority journal; Chromatography, Liquid; Hydrogen-Ion Concentration; Kinetics; Pharmaceutical Preparations; Solutions