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Simultaneous determination of diclofenac and its common counter‐ions in less than 1 minute using capillary electrophoresis with contactless conductivity detection
Author(s) -
Cunha Rafael R.,
Gimenes Denise T.,
Munoz Rodrigo A. A.,
do Lago Claudimir L.,
Richter Eduardo M.
Publication year - 2013
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.201300008
Subject(s) - capillary electrophoresis , chemistry , analyte , conductivity , detection limit , flame photometry , analytical chemistry (journal) , chromatography , electrolyte , conductometry , diclofenac sodium , stoichiometry , potassium , electropherogram , electrode , organic chemistry
This paper presents a method for fast and simultaneous determination of diclofenac ( DCF ) and its common counter‐ions (potassium, sodium, and diethylammonium) using CE with capacitively coupled contactless conductivity detection ( CE ‐ C 4 D ). On the basis of a single electropherogram (about 50 s), the proposed method allows the determination of the stoichiometry, absolute quantification and evaluation of the degradation degree of the active pharmaceutical ingredient ( DCF ). A linear working range from 100 to 500 μmol/L was obtained for all analytes in an equimolar TRIS / TAPS (10 mmol/L) solution as the background electrolyte as well as adequate LOD (7, 6, 7, and 10 μmol/L for K + , N a + , diethylammonium, and DCF , respectively). The proposed method was applied to the analysis of pharmaceutical formulations (tablets and spray form) with similar results to those achieved by HPLC ( DCF ) or flame photometry ( K and N a) at a 95% confidence level.