Separation and migration behavior of structurally related phenothiazines in cyclodextrin-modified capillary zone electrophoresis

• Published in: Journal of Chromatography A 2002-12, Vol.979 (1), p.399-408
• Main Authors: Chen, Kuo-Hsing, Lin, Ching-Erh, Liao, Wei-Ssu, Lin, Wann-Yin, Hsiao, Yu-You
• Format: Article
• Language: English
• Subjects: Analysis; Biological and medical sciences; Buffers; Cyclodextrins; Cyclodextrins - chemistry; Electrophoresis, Capillary - methods; General pharmacology; Hydrogen-Ion Concentration; Medical sciences; Pharmacology. Drug treatments; Phenothiazines; Phenothiazines - chemistry; Phenothiazines - isolation & purification
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(02)01501-7

The influences of buffer pH and the concentration of β-cyclodextrins (β-CDs) on the separation and migration behavior of 13 structurally related phenothiazines in CD-modified capillary zone electrophoresis (CD-CZE) using a phosphate background electrolyte at low pH were investigated. We focused on the separation of these phenothiazines, including the enantiomers of chiral analytes, with the use of β-CD and hydroxypropyl-β-CD (HP-β-CD) as electrolyte modifiers or chiral selectors at concentrations less than 8 m M. The results indicate that the interactions of phenothiazines with β-CDs are very strong and that effective separations of 13 analytes can be achieved with addition of 0.3 m M β-CD or 0.5 m M HP-β-CD in a phosphate buffer at pH 3.0. Binding constants of phenothiazines to β-CDs were evaluated for a better understanding of the interactions of phenothiazines with β-CDs.