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

Abstract

Chromatographic separation and analysis of complex mixtures of closely related species is one of the most challenging tasks in modern pharmaceutical analysis. In recent years, two-dimensional liquid chromatography (2D-LC) has become a valuable tool for improving peak capacity and selectivity. However, the relatively slow speed of chiral separations has limited the use of chiral stationary phases (CSPs) as the second dimension in 2D-LC, especially in the comprehensive mode. Realizing that the recent revolution in the field of ultrafast enantioselective chromatography could now provide significantly faster separations, we herein report an investigation into the use of ultrafast chiral chromatography as a second dimension for 2D chromatographic separations. In this study, excellent selectivity, peak shape, and repeatability were achieved by combining achiral and chiral narrow-bore columns (2.1 mm × 100 mm and 2.1 mm × 150 mm, sub-2 and 3 μm) in the first dimension with 4.6 mm × 30 mm and 4.6 mm × 50 mm columns packed with highly efficient chiral selectors (sub-2 μm fully porous and 2.7 μm fused-core particles) in the second dimension, together with the use of 0.1% phosphoric acid/acetonitrile eluents in both dimensions. Multiple achiral × chiral and chiral × chiral 2D-LC examples (single and multiple heart-cutting, high-resolution sampling, and comprehensive) using ultrafast chiral chromatography in the second dimension are successfully applied to the separation and analysis of complex mixtures of closely related pharmaceuticals and synthetic intermediates, including chiral and achiral drugs and metabolites, constitutional isomers, stereoisomers, and organohalogenated species.

Optimizing separations in online comprehensive two‐dimensional liquid chromatography

“…Barhate et al. developed an RPLC × Chiral‐LC and Chiral‐LC × Chiral‐LC methods to study isomers of a synthetic pharmaceutical intermediate .…”

“…This drastic reduction of the analysis time has made it possible to develop a chiral-separation method as 2 D in LC × LC separations. Barhate et al developed an RPLC × Chiral-LC and Chiral-LC × Chiral-LC methods to study isomers of a synthetic pharmaceutical intermediate [153].…”

Enantiomers separation by capillary electrochromatography using polysaccharide‐based stationary phases

“…Enantiomer separation has been performed utilizing different analytical techniques such as GC, TLC, SFC, HPLC, and CE [1][2][3][4][5][6][7][8][9][10][11].…”

High‐performance liquid chromatography quantification of enantiomers of a Dihydroxylated tetrahydrofuran natural product

“…Gas chromatography and high performance liquid chromatography analysis of various optically active stationary phases are standard methods for determining pheromone concentrations. However, separating chiral molecules remains a challenge, and requires chiral stationery phase columns and careful chromatographic techniques …”

“…However, separating chiral molecules remains a challenge, and requires chiral stationery phase columns 16 and careful chromatographic techniques. 17,18 The sea lamprey (Petromyzon marinus) is a parasitic vertebrate in the Laurentian Great Lakes, whose invasion resulted in major ecological disaster. Pheromone communication in sea lamprey is increasingly well understood and it has been shown that they rely on pheromones during migration and reproduction.…”