The impact of silica gel pore and particle sizes on HPLC column efficiency and resolution for an immobilized, cyclodextrin‐based, chiral stationary phase

Abstract

In this study, the CD derivative, mono (6(A)-azido-6(A)-deoxy)-per(p-chlorophenylcarbamonylated) β-CD was chemically immobilized onto the surface of an amino-functionalized silica gel with different pore (100, 300, and 500Å) and particle (3, 5, and 10 μm) sizes to obtain novel chiral stationary phases. The impact of pore and particle size on the amount of immobilized Ph-β-CD, column performance, and enantioselectivity was investigated by evaluating the separation of a variety of racemates in both the normal- and the reversed-phase modes. Experimental results revealed that the retention factor and resolution of racemates generally decreased with increasing pore size; the column prepared with the smallest (3 μm) silica gel particle size gave the best column performance and enantioselectivity in both the normal- and the reversed-phase modes.

A new single‐urea‐bound 3,5‐dimethylphenylcarbamoylated β‐cyclodextrin chiral stationary phase and its enhanced separation performance in normal‐phase liquid chromatography

“…Elemental analysis found (%): C 15.16, H 2.23, N 2.02. Surface concentration of the β‐CD derivatives: 0.172 μmol⋅m −2 . The detailed characterization data of the SDMP were presented in the supporting information.…”

Sub-2 μm Silica Particles in Chiral Separation

“…Retention is directly related to surface area; therefore, the use of large-pore columns is not desirable when small-pore columns can be used [13]. Selection of the pore size is based on providing easy access for the molecules to the pores in the column [10][11][12].…”

“…Selection of the pore size is based on providing easy access for the molecules to the pores in the column [10][11][12]. Consequently, the higher surface area associated with small pore-columns is preferred mainly because the analytes are small enough to pass through the pores [12,13].…”

Self-Immobilization of Poly(methyltetradecylsiloxane) onto Metalized Silica Particles as Stationary Phases for HPLC

“…It is also simpler and more reproducible as it requires no strict control of the preparation conditions. 10 Polymer immobilization on the support surface is typically performed by a chemical process [11][12][13] or by a physical process such as thermal treatment, 7,14,15 gamma ionizing radiation, [16][17][18] and microwave radiation. 8,19 The mechanisms of these treatments on the polymer immobilization process is not yet well understood, although the resulting material typically has a thin polymer layer chemically bonded to some of the active sites of the chromatographic support, which results in good separations and high stability.…”