Chiral separations by non-aqueous capillary electrophoresis in DMSO-based background electrolytes

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) excels in enantioseparation due to efficiency and versatility.
• Non-aqueous capillary electrophoresis (NACE) is suitable for poorly water-soluble chiral compounds.
• Volatile alcoholic background electrolytes (BGEs) in NACE cause current instability and composition changes.

Purpose of the Study:

• To evaluate dimethyl sulfoxide (DMSO) as a background electrolyte (BGE) for NACE enantioseparations.
• To optimize experimental conditions for resolving chiral drugs using DMSO in NACE.
• To assess DMSO's suitability as a replacement for volatile alcoholic BGEs in NACE.

Main Methods:

• Non-aqueous capillary electrophoresis (NACE) was employed.
• Dimethyl sulfoxide (DMSO) was investigated as the background electrolyte (BGE).
• Experimental variables were optimized to enhance enantioresolution for three model drugs.

Main Results:

• Complete enantioseparation was achieved for verapamil (Rs=1.5) and pindolol (Rs=2.0).
• Partial resolution was obtained for fenfluramine (Rs=1.2).
• DMSO proved effective and stable as a BGE in NACE.

Conclusions:

• Dimethyl sulfoxide (DMSO) is a viable and stable alternative BGE for NACE enantioseparations.
• NACE using DMSO overcomes the limitations associated with volatile alcoholic BGEs.
• This method provides efficient chiral separations for specific non-water-soluble drugs.