Synthesis of poly(N‐[tris(hydroxymethyl)methyl]acrylamide) functionalized porous silica for application in hydrophilic interaction chromatography

Abstract

Porous silica coated by a highly hydrophilic and nonionic tentacle-type polymeric layer was synthesized by free radical "grafting from" polymerization of N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-2-propenamide (TRIS-acrylamide) in partly aqueous solutions. The radical initiator sites were incorporated on the silica surfaces via a two-step reaction comprising thionyl chloride activation and subsequent reaction with tert-butyl hydroperoxide. The surface-bound tert-butylperoxy groups were then used as thermally triggered initiators for graft polymerization of TRIS-acrylamide. The synthesized materials were characterized by diffusive reflectance Fourier transform infrared specotroscopy, X-ray photoelectron spectroscopy, and CHN elemental analysis. Photon correlation spectroscopy was used to determine changes in ζ-potentials resulting from grafting, (29)Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS-NMR) spectroscopy was used to assess the ratio of silanol to siloxane groups in the substrate and the grafted material, and the changes in surface area and mesopore distribution were determined by nitrogen cryosorption. Chromatographic evaluation in hydrophilic interaction chromatography (HILIC) mode showed that the materials were suitable for use as stationary phases, featuring good separation efficiency, a comparatively high retention, and a selectivity that differed from most commercially available HILIC phases. A comparison of this neutral phase with a previously reported N-(2-hydroxypropyl)-linked TRIS-type hydrophilic tentacle phase with weak anion exchange functionality revealed substantial differences in retention patterns.

Functional Interfaces Constructed by Controlled/Living Radical Polymerization for Analytical Chemistry

“…HILIC has shown great advantages in the separation of polar compounds with biological importance (i.e., amino acids, nucleosides, peptides, oligosaccharides, polar organic compounds, and organic acids). − The mobile phases of HILIC are dominantly containing water (or acidic/basic buffer), − which requires more stable stationary phases compared with silica supports. The polymeric supports for preparing HILIC stationary phases have exhibited satisfactory performances for the separation of the polar compounds.…”

Alkaloid purification using rosin‐based polymer‐bonded silica stationary phase in HPLC

“…As the core component of HPLC system, the stationary phase has attracted significant attention among chromatographic researchers [12,13]. Especially, porous silica matrix is most commonly used in HPLC columns [14] and has been paid more attention due to its large surface area for outstanding binding capacity, easily controllable pore structure for targeted molecules loading, and low cytotoxicity for biological compatibility in vivo [15][16][17]. polymers because of their high resistance toward nonspecific adsorption [18], good matrix chemical protection [19], and extremely high functional group density [20].…”

Polar silica‐based stationary phases. Part I ‐ Singly and doubly layered sorbents consisting of TRIS‐silica and chondroitin sulfate A‐TRIS‐silica for hydrophilic interaction liquid chromatography

“…This polymer coated stationary phase exhibited hydrophilic interactions and weak anion exchange mixed mode retention properties in the separation of polar neutral, acidic and basic solutes under HILIC conditions. An analog TRIS acrylamide grafted silica stationary phase containing amide linkages between TRIS functionalities and graftchains of polymer coating has been reported instead of secondary amine linkages employed previously . This TRIS acrylamide grafted silica gel showed different selectivity, substantially higher retention capacity and reduced weak anion exchange properties compared to those of the TRIS amine silica stationary phase.…”