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Separation and on‐column preconcentration of some nonsteroidal anti‐inflammatory drugs by microemulsion electrokinetic capillary chromatography using high‐speed separations
Author(s) -
Macià Alba,
Borrull Francesc,
Calull Marta,
Aguilar Carme
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200410239
Subject(s) - chromatography , chemistry , microemulsion , electrokinetic phenomena , sodium dodecyl sulfate , micellar electrokinetic chromatography , electrolyte , analyte , capillary action , acetonitrile , ethyl acetate , capillary electrophoresis , analytical chemistry (journal) , pulmonary surfactant , electrode , materials science , biochemistry , composite material
Various strategies have been investigated for separating a group of nonsteroidal anti‐inflammatory drugs (NSAIDs) by microemulsion electrokinetic capillary chromatography (MEEKC) using high‐speed separations. The parameters that of affect the separation, such as the nature of the oil droplet and the buffer, and the surfactant concentration have been studied. In addition, several organic solvents were used to decrease the retention of the analytes in the oil droplet phase and to improve the resolution of the NSAIDs. The optimum microemulsion background electrolyte (BGE) solution made of 0.8% w/w ethyl acetate, 6.6% w/w butan‐1‐ol, 6.0% w/w acetonitrile, 1.0% w/w sodium dodecyl sulfate (SDS), and 85.6% w/w of 10 m M sodium tetraborate at pH 9.2 resolved the drugs within 8 min. The short‐end injection procedure is an alternative for reducing the analysis time. When this procedure was used, the microemulsion BGE solution consisted of 0.8% w/w ethyl acetate, 6.6% w/w butan‐1‐ol, 17.0% w/w methanol, 1.0% w/w SDS, and 74.6% w/w of 10 m M sodium tetraborate, pH 9.2, and the NSAIDs were separated within 3 min. The reversed electrode polarity stacking mode (REPSM) technique was applied to the on‐line concentration of the NSAIDs. In this technique, the sample matrix was pumped out of the capillary using a polarity‐switching step. When this technique was applied, the sensitivity was enhanced up to 40‐fold and the limits of detection (LODs) were in the low μg·L ‐1 levels.