Comparative study of capillary zone electrophoresis and micellar electrokinetic chromatography for the separation of twelve aromatic sulphonate compounds

Abstract

SummaryTwo modes of capillary electrophoresis (CE), capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC), were investigated for the separation of 12 aromatic sulphonate compounds. In CZE, although the voltage applied, the buffer concentration and the pH were optimized for effective separation of the compounds studied, under the best conditions four of the five amino compounds coeluted, as did naphthalene-l-sulphonic acid and naphthalene-2-sulphonic acid. In MEKC, sodium dodecyl sulphate (SDS) and Brij 35 were chosen as the anionic and nonionic surfactants and the effect of the concentration of micelles was examined. The effect of adding methanol as the organic modifier was also investigated with each of these micellar systems. All the analytes, including the isomers, were completely separated by use of MEKC with Brij 35 but when SDS was used only 11 compounds were separated because two amino compounds coeluted.

Capillary electrophoretic separation of sulphonated anthraquinones in a variety of matrices

“…Although it has previously been shown that micellar electrokinetic chromatography (MEKC) gives better results than capillary zone electrophoresis (CZE) for sulphonated aromatic compounds [21], consistent results could not be obtained by use of MEKC with the five sulphonated anthraquinones under investigation in this work. Indeed, neither the reproducibility of the peak migration times nor peak shapes was satisfactory (results not shown).…”

Evaluation of coelectroosmotic capillary zone electrophoresis for the rapid analysis of twelve aromatic sulphonate compounds

“…The analysis time is considerably shorter when coelectroosmotic CZE (Figure 2b) is used instead of counterelectroosmotic CZE [7]. The analysis time varies from 6 rain for coelectroosmotic CZE to 14 min for counterelectroosmotic CZE.…”

“…Stock aqueous solutions of CTAB and HDB were prepared weekly at 20 mM and 0.5 % (w/v) respectively. All buffer solutions were 20 mM sodium tetraborate, pH 8.7 [7] and the appropriate amounts of CTAB or HDB and organic solvent. Before use, buffer solutions were sonicated and filtered through a 45-pro nylon syringe-filter (Corning, USA).…”

“…Although gas chromatography (GC) [1], ion-pair liquid chromatography (IPLC) [2,3], and ion-interaction chromatography (IIC) [4] are well-established techniques for the analysis of the positional isomers of compounds, capillary electrophoresis (CE) [5][6][7] is emerging as an alternative technique that overcomes some of the drawbacks of the other methods (e.g. complex derivatization processes in GC).…”

Separation of aromatic sulfonate compounds by coelectroosmotic micellar electrokinetic chromatography

“…Since initial work by Terabe and coworkers [I, 2], MEKC has developed into a routine separation technique for improving separation efficiency not only for uncharged compounds but also for many ionic compounds. Some ionic analytes not successfully separated by capillary zone electrophoresis (CZE) can be separated by MEKC [3,4].…”