Analysis of colistin sulfate by capillary zone electrophoresis with cyclodextrins as additive

Citation
Jw. Kang et al., Analysis of colistin sulfate by capillary zone electrophoresis with cyclodextrins as additive, ELECTROPHOR, 21(15), 2000, pp. 3199-3204
Citations number
20
Categorie Soggetti
Chemistry & Analysis
Journal title
ELECTROPHORESIS
ISSN journal
01730835 → ACNP
Volume
21
Issue
15
Year of publication
2000
Pages
3199 - 3204
Database
ISI
SICI code
0173-0835(200009)21:15<3199:AOCSBC>2.0.ZU;2-W
Abstract
A method for the quantitative analysis of colistin sulfate by capillary zon e electrophoresis is described. Since colistin components have five free am ino groups, they tend to adsorb onto the capillary wall and cause peak tail ing. It was found that triethanolamine (TEA)-phosphate buffer at pH 2.5 was useful to reduce such adsorption. Methyl-beta-cyclodextrin (M-beta-CD) and 2-propanol (IPA) were found necessary for selectivity enhancement. In orde r to optimize the separation parameters and predict the method robustness, a central composite design was performed including three variables, namely concentration of M-beta-CD, TEA, and IPA. The effects of capillary length a nd applied voltage on separation were also investigated. The optimal condit ions established were: 140 mM TEA-phosphate buffer containing 5 mM M-beta-C D and 6% v/v IPA, a capillary with 55 cm total length (50 mu m inner diamet er, 47 cm from inlet to detection window) and 24 kV applied voltage. The me thod was found to be robust when the variables were changed in the followin g range: 4-6 mM M-beta-CD, 5-7% v/v IPA, and 130-150 mM TEA. Further, the l inearity, limit of detection (LOD), and limit of quantitation (LOQ), as wel l as repeatability far both colistin A and B were examined and three commer cial samples were quantitatively analyzed.