Gone in Seconds: Praxis, Performance, and Peculiarities of Ultrafast Chiral Liquid Chromatography with Superficially Porous Particles

Abstract

A variety of brush-type chiral stationary phases (CSPs) were developed using superficially porous particles (SPPs). Given their high efficiencies and relatively low back pressures, columns containing these particles were particularly advantageous for ultrafast "chiral" separations in the 4-40 s range. Further, they were used in all mobile phase modes and with high flow rates and pressures to separate over 60 pairs of enantiomers. When operating under these conditions, both instrumentation and column packing must be modified or optimized so as not to limit separation performance and quality. Further, frictional heating results in axial thermal gradients of up to 16 °C and radial temperature gradients up to 8 °C, which can produce interesting secondary effects in enantiomeric separations. It is shown that the kinetic behavior of various CSPs can differ from one another as much as they differ from the well-studied C18 reversed phase media. Three additional interesting aspects of this work are (a) the first kinetic evidence of two different chiral recognition mechanisms, (b) a demonstration of increased efficiencies at higher flow rates for specific separations, and

Enantioselective ultra high performance liquid and supercritical fluid chromatography: The race to the shortest chromatogram

“…In these papers, the analysis of how extracolumn effects, frictional heating, and detector effects on ultra‐fast separations was considered. In addition, with the use of 3 cm short columns and high flow rates (4.50–4.95 mL/min), ultra‐fast enantiomeric separation was achieved for all CSPs as reported in Figure . In detail, the representative ultra‐fast enantiomeric separations in Figure refer to selectors: (A) vancomycin, (B) teicoplanin aglycone, (C) hydroxylpropyl‐β‐cyclodextrin, (D) teicoplanin, (E) cyclofructan‐7 d imethylphenyl carbamate, and (F) cyclofructan‐6‐derivatized isopropyl carbamate.…”

Resolving power in liquid chromatography: A trade‐off between efficiency and analysis time

“…Patel et al. described ultra‐fast separations of over 60 pairs of enantiomers within the 4–40 s range . In a follow‐up study, Wahab et al.…”

Evaluation of the Edman degradation product of vancomycin bonded to core‐shell particles as a new HPLC chiral stationary phase

“…Since the recent development of superficially porous particles or core‐shell particles, which offer high throughput and more effective separations, several studies have been explored using core‐shell macrocyclic glycopeptide‐based CSPs (TeicoShell [TS] and VancoShell [VS]) . This has been particularly useful to ultrafast chiral separations needed in second dimension (2D) LC . However, many glycopeptides are costly and have limited availability, which has led to a need to understand the applicability and limitations of more available glycopeptides so further exploration can be made concerning useful modifications.…”

“…[21][22][23][24][25] This has been particularly useful to ultrafast chiral separations needed in second dimension (2D) LC. [24][25][26][27][28][29] However, many glycopeptides are costly and have limited availability, which has led to a need to understand the applicability and limitations of more available glycopeptides so further exploration can be made concerning useful modifications.…”