Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, 44121 Ferrara, Italy.
Department of Drug Chemistry and Technology, "Sapienza" University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy.
J Chromatogr A. 2018 Dec 7;1579:41-48. doi: 10.1016/j.chroma.2018.10.022. Epub 2018 Oct 15.
The adsorption isotherms of trans-stilbene oxide (TSO) enantiomers have been measured under a variety of normal phase (NP) mobile phases (MPs) on three Whelk-O1 chiral stationary phases (CSPs), prepared respectively on 1.8 μm and 2.5 μm fully porous particles (FPPs) and 2.6 μm superficially porous particles (SPPs). Specific loading of chiral selector (moles per square meter) of the two FPPs was about 20% smaller than that of SPPs (even if they were prepared under exactly the same experimental conditions). Regardless of particle size or format, adsorption was described by means of a Bilangmuir model with ethanol/hexane MPs. On the other hand, in pure hexane, the Tóth isotherm was employed. Interestingly, it was found that selective and nonselective Henry's constants vary in opposite directions by increasing the percentage of strong MP modifier (between 3 and 10%, v/v). Saturation capacity of SPPs (referred only to the porous zone of the particle) was remarkably smaller than those of FPPs. On the other hand, binding constants on both selective and nonselective sites were significantly larger on SPPs. Finally, a correlation between the specific loading of chiral selector and the binding constants of enantiomers was suggested by data, which can be important also to understand the kinetic behavior of these particles in chiral ultrafast applications.
反式氧化亚乙烯（TSO）对映异构体的吸附等温线在三种 Whelk-O1 手性固定相（CSP）上的多种正相（NP）流动相（MP）下进行了测量，这三种 CSP 分别是在 1.8μm 和 2.5μm 全多孔颗粒（FPP）和 2.6μm 表面多孔颗粒（SPP）上制备的。两种 FPP 的手性选择剂的比负载量（每平方米的摩尔数）比 SPP 小约 20%（即使它们是在完全相同的实验条件下制备的）。无论颗粒尺寸或形态如何，吸附都可以通过乙醇/己烷 MPs 的 Bilangmuir 模型来描述。另一方面，在纯己烷中，采用了 Tóth 等温线。有趣的是，发现选择性和非选择性亨利常数随着强 MP 改性剂（3%至 10%，v/v）百分比的增加而呈相反方向变化。SPP 的饱和容量（仅指颗粒的多孔区）明显小于 FPP 的饱和容量。另一方面，在 SPP 上，选择性和非选择性位点的结合常数都显著增大。最后，通过数据提出了手性选择剂的比负载量与对映体结合常数之间的相关性，这对于理解这些颗粒在手性超快应用中的动力学行为也很重要。
