Hydroxypropyl‐β‐cyclodextrin encapsulated stationary phase based on silica monolith particles for enantioseparation in liquid chromatography

Abstract

Hydroxypropyl‐β‐cyclodextrin‐encapsulated stationary phase incorporated on silica monolith particles was prepared by physical embedding, providing a new method for the development of chiral stationary phase for enantioseparation in liquid chromatography. Ground silica monolith particles of about 2.0 μm were prepared via sol–gel reaction followed by differential sedimentation. Initially, the silica monolith particles were pretreated with 3‐trimethoxysilyl propyl methacrylate to attach double‐bonded ligands onto the surface, then a network structure was formed onto the surface of the particle using N‐isopropyl acrylamide as functional monomer. Hydroxypropyl‐β‐cyclodextrin was encapsulated inside N‐isopropyl acrylamide copolymerized layer on the surface of silica monolith particles. The effect of the amount of chiral selector on the chromatographic efficiency of the chiral stationary phase was examined. The glass lined stainless steel columns (1 mm internal diameter, 300 mm length) were packed with the stationary phase for estimation of the efficiency by separation of phenylsuccinic acid, oxybutynin, equol, and naproxen enantiomers in high‐performance liquid chromatography, with the resolutions of 1.54, 1.72, 2.54, and 2.31, respectively. The column to column repeatabilities through relative standard deviation were found better than 3%. The experimental results indicate that the sol‐gel ground silica particles modified with β‐cyclodextrin provide a promising way for the separation of chiral enantiomers.

Fast liquid chromatography method for separation of peptides using a sub‐2 μm ground silica monolith packed column

“…According to the work [20], the sub‐2 μm particles were obtained from monolith using sol‐gel process followed by grinding. Urea 100 g and PEG 100 g were dissolved in 0.01M acetic acid (800 mL) and 300 mL TMOS was added in a Teflon container, and the mixture was stirred for 60 min steadily under ice/water cold condition.…”

Open tubular capillary column immobilized with sulfobutylether‐β‐cyclodextrin for chiral separation in capillary electrochromatography

“…The fused-silica capillary (120 cm length) was pretreated according to the previously reported procedure in earlier studies [18]. First, the capillary was filled with 1 mol/L sodium hydroxide solution, sealed with rubbers at both ends, stored at 55 • C for 48 h. The capillary was washed with water, 0.1 mol/L HCl, and again with water to achieve neutrality, flushed with acetone for 1 h, and dried with N 2 at 120 • C for 2 h to expose the silanol functionalities.…”

“…β‐Cyclodextrin and its derivatives are the most common chiral selectors in chromatographic enantioseparation of chiral compounds. The chiral selector sulfobutylether‐β‐cyclodextrin (SBE‐β‐CD) [17] and hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) [18], have been regarded as a class of very effective and extraordinary chiral selectors. These chiral selectors interact with molecules selectively to form inclusion complexes on the basis of the size, polarity, and shape of the chiral molecules.…”

Growth of two‐layer copolymer as the stationary phase with very high separation efficiency for separating peptides in capillary electrochromatography

“…The driven EOF increases the interaction between analytes and stationary phase providing high separation efficiency of the capillary column. The capillary columns including granular packed column [5–7], monolithic columns [8–11], and open tubular CEC (OT‐CEC) column [12–14] are commonly used to separate compounds in CEC.…”