Chiral separation of five triazole antifungals by capillary zone electrophoresis

Key words: 
• capillary zone electrophoresis /
• β-cyclodextrin derivative /
• triazole /
• chiral separation

Abstract: Objective: To investigate the factors that influence the chiral separation of triazole antifungals by capillary zone electrophoresis using β-cyclodextrin derivatives as chiral selector. Methods: Analyse were carried out on a P/ACE 5000 capillary electrophoresis system(Beckman,USA) with a UV detector,using an uncoated fused-silica capillary 50 μm × 47 cm with an effective length of 40 cm.Samples were injected into the capillary by 50 mbar pressure for 3 s.The detective wavelength was set at 200 nm.Three β-cyclodextrin derivatives were used as chiral selectors. Results: Satisfactory separation of the five triazole antifungals were achieved when using carboxymethylated-β-cyclodextrin(CM-β-CD) while the sulfobutyl-ether-β-cyclodextrin(SBE-β-CD) and difluoro-carboxymethylated-β-cyclodextrin showed no chiral separation ability to the five triazole antifungals.When using CM-β-CD,the enantiomeric separation of the five compounds and the best results were obtained in 30 mmol/L NaH2PO4 buffer(adjust to pH 2.2 with H3PO4)containing 5 mmol/L CM-β-CD.The voltage was 20 KV and the temperature was 20 ℃.The five triazole compounds were well separated on this condition. Conclusion: The type of β-CD and the pH of buffer is the major factor influencing the separation of the five triazole antifungals.