Gone in Seconds: Praxis, Performance, and Peculiarities of Ultrafast Chiral Liquid Chromatography with Superficially Porous Particles (original) (raw)
Related papers
Journal of Chromatography A, 2010
Three brush-type chiral stationary phases (CSPs) differing in the particle size of the starting silica particles have been prepared by covalent grafting of the -acidic bis-(3,5-dinitrobenzoyl)-derivative of trans-1,2-diaminocyclohexane (DACH-DNB). Starting silica particles of 4.3, 2.6 and 1.9 micron were used to generate the final CSPs using an improved, highly reproducible synthetic methodology, that allowed to assemble and surface-graft the whole chiral selector in only two steps. The different CSPs have been packed in columns of various length and diameters, and fully characterized in terms of flow permeability, kinetic performances and enantioselectivity using a set of test solutes. Very high speed and high resolution applications together with stereodynamic HPLC examples are demonstrated on the columns with reduced particle diameters, on which separations of several enantiomeric pairs are routinely obtained with analysis times in the 15-40 s range.
Analytical and bioanalytical chemistry, 2018
About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of chiral chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for achiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evo...
Journal of chromatography. A, 2016
Pirkle-type Whelk-O1 chiral stationary phase (CSP) was prepared on 2.6μm superficially porous particles (SPPs). The chromatographic behavior of columns packed with this new CSP was compared with that of columns packed respectively with 1.8 and 2.5μm Whelk-O1 fully porous particles (FPPs). In the comparison, both thermodynamic and kinetic aspects were considered. Contrary to initial expectations, chiral columns packed with 2.6μm SPPs were quasi-comparable to those packed with 2.5μm FPPs, apparently due to larger contributions to band broadening from both eddy dispersion and, especially for the second eluted enantiomer, adsorption-desorption kinetics. These findings raise the question if SPPs, in spite of the undeniable advantages of their morphology to speed up mass transfer, are always the best choice for high-efficient ultrafast chiral separations. The last part of the work focuses on the use of short columns (10mm long) and very high flow rates to realize the separation of the ena...
Journal of Chromatography A, 2018
Our earlier studies have demonstrated the applicability of polysaccharide-based chiral selectors in combination with superficially porous (or core-shell) silica (SPS) particles for the preparation of highly efficient chiral stationary phases (CSP). In earlier studies, CSPs were prepared by coating (adsorption) of the chiral selector onto the surface of silica. In this study we report for the first time the CSP obtained by covalent immobilization of a chiral selector onto the surface of SPS particles. The applicability of this CSP for the separation of enantiomers in pure methanol and acetonitrile, as well as in n-hexane/2propanol mobile phases is shown. The effect of the injected sample amount, mobile phase flow rate and detection frequency on separation performance were studied, as well as high efficiency separation of enantiomers with the analysis time less than 30 seconds was attempted.
On our way to sub-second separations of enantiomers in high-performance liquid chromatography
Journal of Chromatography A, 2018
In this study our preliminary attempt for obtaining fast and highly efficient separations of enantiomers in high-performance liquid chromatography with slightly modified state-of-the-art commercial instrumentation is described. In order to reach this goal after careful selection of chiral analytes, the preparation of chiral stationary phase (CSP), mobile phase composition and column dimensions were optimized. The concept of segmented chiral-achiral column was introduced. As the result of these optimizations baseline separation of enantiomers was achieved with the analysis time between 1-2 seconds.
Recent applications in chiral high performance liquid chromatography: A review
Analytica Chimica Acta, 2011
The most important and broadly used chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC) are reviewed. After a short description of the state of the art, for each kind of CSP the most important contributions published in the last couple of years are summarized. For the sake of classification, these works have been divided into studies on enantiorecognition mechanisms, new materials, and new applications. Emphasis is given to new, emerging CSPs that seem to possess all requisites to be considered potentially successful chiral separation media in the next future.
Journal of chromatography. A, 2014
Fast chiral supercritical fluid chromatography (SFC) separations have become important due to 12 the increasing use of high throughput experimentation (HTE) in organic synthesis. These HTE 13 experiments can generate hundreds of samples for chiral analysis that need to be assayed in a 14 short time. In general, chiral SFC can provide much faster analysis times compared to liquid 15 chromatography (LC). Additionally, columns packed with smaller particles can provide faster 16 and more efficient separations. In this study, the effect of the particle size on the speed and 17 resolution of chiral separations by SFC was evaluated. The performance of Chiralcel OD 18 columns packed with either 5 µm or 3 µm particles were compared using van Deemter and other 19 kinetic plots. The results clearly illustrate the benefits of using smaller particle stationary phases 20 for improved speed and chiral chromatographic performance by SFC.