Chiral separations on polysaccharide stationary phases using polar organic mobile phases

Abstract

About 30% of a chemically diverse set of compounds were found to separate on four polysaccharide chiral stationary phases using polar organic mobile phases. No structural features appeared to correlate to successful separations. Titrations between normal and polar organic mobile phases suggested that separation mechanisms do not differ between these mobile phases. Attempts made to control retention met with varying degrees of success. Addition of hexane to alcohols had minor effects on retention although this was occasionally beneficial. Addition of water to alcohols increased retention. Addition of water to acetonitrile decreased retention. Addition of alcohol to acetonitrile also proved beneficial to the separation of some compounds. Loading studies performed to mimic preparative separations indicated that the benefits of polar organic mobile phases are largely due to increased solubility.

Effects of diethylamine on Capillary Chromatographic Enantioseparation of Some Chiral Analytes Using Polysaccharide Stationary Phases with Pure Polar Solvents as Mobile Phases

“…Three compounds (1-3) among the used 18 analytes do not contain nitrogen atoms in their structures, while the other compounds contain nitrogen atoms as primary amine (4) or secondary hydroxylamine at side chain (5-10; β-blockers), or as heterocyclic compounds (11)(12)(13)(14)(15)(16)(17)(18). The capillary chromatographic runs of these compounds were carried out on CDMPC and ADMPC stationary phases.…”

“…[1][2][3][4][5][6][7][8] However, some polar organic solvents, such as methanol, ethanol or acetonitrile have been used effectively on these stationary phases in recent days. 5,[9][10][11][12] Polar organic solvents may offer the advantages of alternative chiral recognition mechanisms, higher solubility of some analytes and having less environmental problems. 11 Though the separation mechanisms for polysaccharide-type stationary phases are not completely known, the contribution of hydrogen bonding and hydrophobic interaction to retention is commonly accepted.…”

Separation of Chiral Compounds on Polysaccharide Columns

“…A more comprehensive study [2,158] of the chiral recognition behavior of 82 structurally diverse compounds on coated Chiralpak AD, Chiralcel OD, Chiralpak AS, and Chiralcel OJ chiral stationary phases in polar organic, 50 : 50 methanol/ethanol, and acetonitrile mobile phases has been conducted to assess the relative success rates of polar organic mode screening. Out of this set of analytes, 25 compounds (30%) were resolved with selectivity values of 1.5 or greater, while some additional compounds were separated with selectivity values of less than 1.5.…”

Direct and indirect separations of five isomers of Brivanib Alaninate using chiral high-performance liquid chromatography☆

“…The use of polar organic separation mode, which utilizes polar organic solvents such as alcohols, acetonitrile or their mixtures as mobile phase, offers a few advantages over reversed-phase and normal phase modes, such as higher separation efficiency and increased solute solubility, and has drawn increasing attention in recent years [21,30]. Under polar organic mode, several columns, including OJ-H, OB-H and Sepapak-4, showed reasonable high enantioselectivity for both enantiomeric pairs ( Table 1).…”