title: Optimized mobile phase for CEC of acetylsalicylic acid and its impurities using a methacrylate-based monolithic column.
abstract: In the past few years, monolithic methacrylate-based columns have attracted some attention in separation science. The mobile-phase optimization on these columns for drug analysis has not yet been thoroughly examined. This paper evaluates the separation of acetylsalicylic acid and its impurities as a case study. First, the best pH was determined as 2.3. Methacrylate-based phases can be employed at such pH because they remain charged, necessary to generate electro-osmotic flow. Then, a suitable solvent strength was determined. Trifluoroacetic acid (0.1%) was added to the mobile phase to improve peak shapes. The optimal organic modifier composition was then determined, using isoeluotropic mobile phases, based on the theory of Snyder's solvent triangle. Quadratic models were built to predict the retention of the compounds at all mobile-phase compositions within the triangle. The predictions were tested and found appropriate. Eventually, a baseline separation of acetylsalicylic acid and its impurities was not obtained. However, it could be concluded that one can optimize the mobile phase on methacrylate-based monolithic columns in CEC using Snyder's solvent triangle approach.
authors.affiliation: Department of Analytical Chemistry and Pharmaceutical Technology, Center for Pharmaceutical Research (CePhaR), Vrije Universiteit Brussel-VUB, Laarbeeklaan, Brussels, Belgium.
authors.forename: Indiana
authors.initials: I
authors.lastname: Tanret
authors.forename: Debby
authors.initials: D
authors.lastname: Mangelings
authors.forename: Yvan
authors.initials: Y
authors.lastname: Vander Heyden
mesh_terms: D001241:Aspirin / Q000032:analysis*; D053801:Capillary Electrochromatography / Q000295:instrumentation / Q000379:methods*; D004340:Drug Contamination; D008689:Methacrylates / Q000737:chemistry
chemical_list: D008689:Methacrylates; D001241:Aspirin