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?

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

“…The idea that chiral SPPs outperform their FPPs counterpart is a consequence of better performance observed for achiral C 18 SPPs compared to the FPPs version. In contrast, some of the authors of the present work published unexpected results by comparing the behavior of brush‐type Whelk‐O1 CSPs made on 2.6 μm SPPs with that of the same selector bonded on both 1.8 and 2.5 μm FPPs . In fact, Ismail et al.…”

“…Reprinted with permission from Ref. [33] compensated by a strong reduction of run time and the separations are completed in 9 s. The figure reports the chromatographic profiles of the same enantioseparation obtained on the first 2.0 μm SPP (for discussion of results, see Section 3.2). In the race to the fastest chiral separation, the finish line has been cut again by Gasparrini's group because of the combined use of short column (1 cm length) and high flow rates (8.0 mL/min).…”

Optimization of the surface modification process of cross‐linked polythiol‐coated chiral stationary phases synthesized by a two‐step thiol‐ene click reaction

“…CSPs with different selector immobilization procedure: brush-type (CSP #15, black line), polysiloxane-coated in one-step synthesis [13] (CSP #14, blue) and polysiloxane-coating by two-step synthesis strategy in CHCl 3 (CSP #12, orange) and MeOH (CSP#13, olive) (closed symbols, first eluted enantiomer; open symbols, second eluted enantiomer) T A B L E 2 Comparison of chromatographic parameters a for tBuCQN-CSPs: brush-type, polysiloxane-coated in one-step synthesis [13] and polysiloxane-coating by two-step synthesis strategy in CHCl 3 appears to be unfavorable for the mass transfer characteristics of this CSP. The optimized two-step PMPMS-tBuCQN CSP #13, on the other hand, is coated with a thin polymer film (0.83 μmol sulfur m −2 ) and has low selector coverage (0.38 μmol m −2 ).…”

“…Enantioselective LC using chiral stationary phases (CSPs) has become a workhorse for chiral separations in drug discovery and quality control of enantiomeric drugs as well as many other applications . In general, two distinctly different concepts for the preparation of CSPs have been pursued: brush type CSPs, in which the chiral selectors are covalently linked to the surface (usually silica) by a spacer and polymeric type CSPs with polymeric selectors . Each of the two concepts, brush‐ and polymer‐type CSPs, has its advantages and disadvantages.…”

“…other applications [1,2]. In general, two distinctly different concepts for the preparation of CSPs have been pursued: brush type CSPs, in which the chiral selectors are covalently linked to the surface (usually silica) by a spacer [3][4][5] and polymeric type CSPs with polymeric selectors [6][7][8][9][10][11][12]. Each of the two concepts, brush-and polymer-type CSPs, has its advantages and disadvantages.…”