Ismail Omar H, Pasti Luisa, Ciogli Alessia, Villani Claudio, Kocergin Jelena, Anderson Scott, Gasparrini Francesco, Cavazzini Alberto, Catani Martina
Dept. of Drug Chemistry and Technology, "Sapienza" Università di Roma, P.le A. Moro 5, 00185 Roma, Italy.
Dept. of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, 44121 Ferrara, Italy.
J Chromatogr A. 2016 Sep 30;1466:96-104. doi: 10.1016/j.chroma.2016.09.001. Epub 2016 Sep 3.
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 enantiomers of trans-stilbene oxide (TSO) in normal phase mode in less than 1s.
在2.6μm表面多孔颗粒（SPP）上制备了Pirkle型Whelk - O1手性固定相（CSP）。将填充这种新型CSP的色谱柱的色谱行为与分别填充1.8μm和2.5μm Whelk - O1全多孔颗粒（FPP）的色谱柱进行了比较。在比较过程中，考虑了热力学和动力学两个方面。与最初的预期相反，填充2.6μm SPP的手性柱与填充2.5μm FPP的手性柱几乎相当，这显然是由于涡流扩散对谱带展宽的贡献更大，尤其是对于第二个洗脱的对映体，吸附 - 解吸动力学的贡献更大。这些发现提出了一个问题，即尽管SPP在加速传质方面具有不可否认的形态优势，但对于高效超快手性分离而言，它们是否总是最佳选择。工作的最后一部分重点在于使用短柱（10mm长）和非常高的流速，以在正相模式下不到1秒的时间内实现反式氧化苯乙烯（TSO）对映体的分离。
