Ultrafast Chiral Chromatography as the Second Dimension in Two-Dimensional Liquid Chromatography Experiments

Area of Science:

• Analytical Chemistry
• Chromatography
• Pharmaceutical Analysis

Background:

• Two-dimensional liquid chromatography (2D-LC) is crucial for separating complex mixtures in pharmaceutical analysis.
• Slow chiral separations have historically limited the use of chiral stationary phases (CSPs) in 2D-LC.
• Advancements in ultrafast enantioselective chromatography offer potential solutions for faster chiral separations.

Purpose of the Study:

• To investigate the application of ultrafast chiral chromatography as a second dimension in 2D-LC.
• To overcome the speed limitations of traditional chiral separations in 2D-LC systems.
• To demonstrate improved separation efficiency for complex pharmaceutical mixtures.

Main Methods:

• Combined achiral and chiral narrow-bore columns in the first dimension with ultrafast chiral columns in the second dimension.
• Utilized sub-2 μm and 3 μm particle sizes for high efficiency.
• Employed 0.1% phosphoric acid/acetonitrile eluents in both dimensions for optimal separation.
• Applied various 2D-LC modes including heart-cutting and comprehensive separations.

Main Results:

• Achieved excellent selectivity, peak shape, and repeatability in separations.
• Successfully separated complex mixtures of pharmaceuticals, synthetic intermediates, and related species.
• Demonstrated the effectiveness of ultrafast chiral columns in the second dimension for both achiral × chiral and chiral × chiral configurations.
• Applied to analyze chiral and achiral drugs, metabolites, isomers, and organohalogenated compounds.

Conclusions:

• Ultrafast chiral chromatography is a viable and powerful second dimension for 2D-LC.
• This approach significantly enhances the separation of complex pharmaceutical mixtures, including stereoisomers.
• The method offers improved peak capacity, selectivity, and speed for challenging analytical tasks.