Effect of fabrication strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized polymethacrylate monoliths: A comparative evaluation

Abstract

To evaluate the effect of the preparation strategy on the enantioseparation performance of β-cyclodextrin-functionalized monoliths, a series of β-cyclodextrin-functionalized organic polymeric monolithic columns were prepared through two-step, single-step, and one-pot approaches, using the same cyclodextrin, linker-spacer, and crosslinker. Physicochemical characterization of the columns was carried out by determining the morphology, β-cyclodextrin density, permeability, and chromatographic efficiency. For each type of monolithic column, the enantioresolution of 22 chiral compounds, including mandelic acid derivatives, nonsteroidal anti-inflammatory drugs, N-derivatized amino acids, and herbicides, was comparatively studied under optimum chromatographic conditions. The β-cyclodextrin-functionalized monolithic columns prepared through the one-pot approach exhibited higher enantioresolution for most chiral compounds, and they have the advantage of good controllability and simple preparation. On the other hand, the enantioresolution obtained on columns prepared through the single-step approach was quite unsatisfactory, and therefore the effect of using different linking spacers and crosslinkers was studied. A significant improvement of enantioresolution for 2-chloro-mandelic acid was obtained by using N,N-methylenebisacrylamide instead of ethylene dimethacrylate as the crosslinker in the single-step preparation.

Cobalt (II)-Mediated Molecularly Imprinted Polymer as a Monolithic Stationary Phase for Separation of Racemic Citronellal by Liquid Chromatography

“…e polymerization of MMIP, MNIP, MIP, and NIP monoliths was conducted in situ or using the one-pot method inside microbore columns made of the silicosteel with an inner diameter of 1 mm. e method was preferred due to the following advantages: it showed a higher enantiomer resolution to separate chiral compounds, faster synthesis than other polymerization methods, provided reasonable control to achieve desired characteristics of the monolith through optimization of chemical and physical parameters, and was easy to perform [28]. A microbore monolith column (1 mm i.d) was used for its easiness to be paired with the HPLC system without modification as compared to the capillary column, and small quantities of enantiomer samples were also another advantage.…”

Chiral Separations by Capillary Electrophoresis and related Techniques with Different Chiral Selectors: A Review

“…Methacrylate-based monolithic columns are one of the materials most prone to development. In addition to being practical, it is shown that the column can be applied sometimes without requiring any silanization pro-cess [105,106,[321][322][323] Denizli et al synthesized chiral monolithic capillary column based on butyl methacrylate in their studies in which the enantiomeric separations of including some of hydrophobic amino acids investigated, which N-Metacryloyl-L-Histidine monomer (MAH) and N-Metacryloyl-L-Glutamic Acid (MAGA) was used as chiral selectors, resptectively in CEC [324,325].…”

A facile and efficient single-step approach for the fabrication of vancomycin functionalized polymer-based monolith as chiral stationary phase for nano-liquid chromatography

“…Recently, increasing efforts have been directed toward the development of organic polymer-based chiral monolithic columns because of their excellent permeability, pH stability, low resistance to mass transfer and high performance [3][4]. So far, various chiral selectors functionalized polymer-based chiral monoliths have been reported, such as cyclodextrin and its derivatives [5][6], quinidine and its derivatives [7][8][9], cellulose derivatives [10], proteins [11,12], macrocyclic antibiotics [13][14], crown ethers [15] and chiral ion-exchangers [16].…”