Separation of nonsteroidal anti-inflammatory drugs by capillary electrophoresis using nonaqueous electrolytes

Autor: Véronique Piette, Jacques Crommen, Marianne Fillet, Isabelle Bechet
Rok vydání: 1999
Předmět:
Zdroj: Electrophoresis. 20(9)
ISSN: 0173-0835
Popis: So far, most capillary electrophoresis (CE) separationshave been carried out in aqueous or, to a lesser extent,mixed aqueous–organic media. Organic solvents havemainly been used in micellar electrokinetic chromatogra-phy (MEKC) and in capillary electrochromatography(CEC), most often to improve the separation of hydro-phobic compounds. Non-aqueous media extended theapplication range of CE to the analysis of compounds ofpoor solubility in water, and also improved the selectivityof the separation of compounds which are characterizedby very similar electrophoretic mobilities in aqueousmedia.The aim of the present work was to investigate theseparation of non-steroidal anti-inflammatory drugs(NSAIDs: niflumic acid, flufenamic acid, piroxicam,alclofenac, flurbiprofen, indomethacin, ketoprofen, na-proxen, carprofen, sulindac) in CE using completely non-aqueous systems. NSAIDs are acidic compoundscharacterized by low solubility in water, and some ofthem have similar charge densities, which makes theirseparation difficult in aqueous systems.In this work, the influence of different parameters suchas nature and proportion of organic solvent (methanol,acetonitrile, 2-propanol), apparent pH (ranging from 7 to9) and temperature (ranging from 25 to 40°C) onselectivity and migration times has been studied system-atically in an uncoated fused silica capillary.Among the three organic solvents tested, methanol wasfound to provide important changes in selectivity. In acompletely methanolic system, the cathodic electro-osmotic flow was strongly decreased in comparison tothe analogous aqueous system (cf. m
Databáze: OpenAIRE
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