Silica Regeneration and Chiral Separation: Comparative Performance of (2-Hydroxyethyl)-β-Cyclodextrin-Grafted Superficially Porous Versus Fully Porous Particles in Reversed-Phase Liquid Chromatography and Supercritical Fluid Chromatography.

Comparison of small size fully porous particles and superficially porous particles of chiral anion-exchange type stationary phases in ultra-high performance liquid chromatography: effect of particle and pore size on chromatographic efficiency and kinetic performance

Until less than 10 years ago, chiral separations were carried out with columns packed with 5 or 3 μm fully porous particles (FPPs). Times to resolve enantiomeric mixtures were easily larger than 30 min, or so. Pushed especially by stringent requirements from medicinal and pharmaceutical industries, during the last years the field of chiral separations by liquid chromatography has undergone what can be defined a “true revolution”. With the purpose of developing ever faster and efficient method of separations, indeed, very efficient particle formats, such as superficially porous particles (SPPs) or sub-2 μm FPPs, have been functionalized with chiral selectors and employed in ultrafast applications. Thanks to the use of short column (1–2 cm long), packed with these extremely efficient chiral stationary phases (CSPs), operated at very high flow rates (5–8 mL/min), resolution of racemates could be accomplished in very short time, in many cases less than 1 s in normal-, reversed-phase and HILIC conditions. These CSPs have been found to be particularly promising also to carry out high-throughput separations under supercritical fluid chromatography (SFC) conditions. The most important results that have been recently achieved in terms of ultrafast, high-throughput enantioseparations both in liquid and supercritical fluid chromatography with particular attention to the very important field of bioactive chiral compounds will be reviewed in this manuscript. Attention will be focused not only on the latest introduced CSPs and their applications, but also on instrumental modifications which are required in some cases in order to fully exploit the intrinsic potential of new generation chiral columns.

Superficially porous particles vs. fully porous particles for bonded high performance liquid chromatographic chiral stationary phases: Isopropyl cyclofructan 6

Future perspectives in high efficient and ultrafast chiral liquid chromatography through zwitterionic teicoplanin-based 2-μm superficially porous particles

Evaluation of superficially porous particle based zwitterionic chiral ion exchangers against fully porous particle benchmarks for enantioselective ultra-high performance liquid chromatography

Size exclusion chromatography with superficially porous particles

Pirkle-type chiral stationary phase on core–shell and fully porous particles: Are superficially porous particles always the better choice toward ultrafast high-performance enantioseparations?

On the effect of chiral selector loading and mobile phase composition on adsorption properties of latest generation fully- and superficially-porous Whelk-O1 particles for high-efficient ultrafast enantioseparations

Intraparticle and interstitial flow in wide-pore superficially porous and fully porous particles

Boosting the enantioresolution of zwitterionic-teicoplanin chiral stationary phases by moving to wide-pore core-shell particles

Ultra high efficiency/low pressure supercritical fluid chromatography with superficially porous particles for triglyceride separation

Impact of straight, unconnected, radially-oriented, and tapered mesopores on column efficiency: A theoretical investigation

Evaluation of stationary phases packed with superficially porous particles for the analysis of pharmaceutical compounds using supercritical fluid chromatography

A superficially porous particle (SPP)-based hydroxypropyl-β-cyclodextrin (HPBCD) chiral stationary phase (CSP) was produced and its chromatographic performance was compared to both 5 µm and 3 µm fully porous particle (FPP)-based CSPs. The relative surface coverage of the HPBCD chiral selector on each particle was approximately equal, which resulted in equivalent enantiomeric selectivity (α) values on each phase when constant mobile phase conditions were used. Under such conditions, the SPP column resulted in greatly reduced analysis times and three times greater efficiencies compared to the FPP columns. When higher flow rates were used, efficiency gains per analysis times were five times greater for the SPP column compared to the FPP-based columns. When the mobile phases were altered to give similar analysis times on each column, resolution values were doubled for the SPP column. Finally, the novel SPP based HPBCD column proved to be stable for 500 injections under high flow rate (4.5 mL/min) and high pressure (400 bar) conditions used for an ultrafast (~45 sec) enantiomeric separation.

Comparison of the most recent chromatographic approaches applied for fast and high resolution separations: Theory and practice