Salient Sub-Second Separations

Abstract

Sub-second liquid chromatography in very short packed beds is demonstrated as a broad proof of concept for chiral, achiral, and HILIC separations of biologically important molecules. Superficially porous particles (SPP, 2.7 μm) of different surface chemistries, namely, teicoplanin, cyclofructan, silica, and quinine, were packed in 0.5-cm-long columns for separating different classes of compounds. Several issues must be addressed to obtain the maximum performance of 0.5 cm columns with reduced plate heights of 2.6 to 3.0. Modified UHPLC hardware can be used to obtain sub-second separations provided extra-column dispersion is minimized and sufficient data acquisition rates are used. Further, hardware improvements will be needed to take full advantage of faster separations. The utility of power transform, which is already employed in certain chromatography detectors, is shown to be advantageous for sub-second chromatography. This approach could prove to be beneficial in fast screening and two-dimensional liquid chromatography.

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

“…In detail, the representative ultra-fast enantiomeric separations in Figure 6 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. The authors also reported sub-second separation of several enantiomers on quinine and teicoplaninbased stationary phases, taking advantage of the beneficial effects of reduced extracolumn volume of the equipment and supported by power transform data processing (Figure 7) [39]. 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.…”

Optimizing separations in online comprehensive two‐dimensional liquid chromatography

“…Chiral chromatography has been mainly used as 2 D separation in heart‐cut approaches . However, recently, the introduction of core–shell particles and UHPLC technology and the re‐emergence of SFC have allowed to drastically reduce the time needed to perform this highly‐specific form of chromatography, reducing the analysis time in some cases to less than a second . This drastic reduction of the analysis time has made it possible to develop a chiral‐separation method as 2 D in LC × LC separations.…”

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

“…The current state‐of‐the‐art high‐throughput separations constitute sub‐second separations reported by the Armstrong research group . Patel et al.…”