Preparation and characterization of hexyl methacrylate monolithic columns for CEC

Abstract

The preparation of hexyl methacrylate (HMA) monolithic columns for CEC separations has been investigated with two initiation systems: (i) ammonium peroxodisulphate and TEMED to activate the polymerization reaction, and (ii) by thermal initiation with AIBN. For both initiators, the influence of composition of porogenic solvent on morphological and chromatographic properties of monoliths was investigated. Two porogenic solvent systems, aqueous and non-aqueous media, were also studied for monolithic beds polymerized with AIBN. Under optimal conditions, low minimum plate heights (9.6 mum for peroxodisulphate, 8.4 and 10.0 mum for AIBN in aqueous and non-aqueous porogenic solvents, respectively) were obtained. A comparison in terms of chromatographic performance of HMA monoliths with butyl methacrylate columns polymerized with both initiators was also performed. The resulting HMA-based stationary phases also exhibited a good repeatability and column-to-column reproducibility, with RSD values below 5.6% in the studied electrochromatographic parameters. The potential of HMA-based columns was demonstrated by the analysis of complex mixtures of polyaromatic hydrocarbons and anabolic steroids.

Adamantyl-functionalized polymer monolith for capillary electrochromatography

“…There are a few data on the reproducibility of preparation of acrylate monolithic columns in the literatures [20][21][22][23][24]. In accordance with previous work [21], the repeatability and reproducibility of preparation of ADM-functionalized monoliths were studied with five monolithic columns synthesized from a polymerization mixture Table 2).…”

CEC column behaviour of butyl and lauryl methacrylate monoliths prepared in non‐aqueous media

“…These polymeric monoliths are usually prepared by in situ polymerization of a mixture composed of functional monomer/s, cross-linker, porogens, and a free radical initiator. Polymerization is commonly initiated thermally [12,[14][15][16][19][20][21][22][23][24][25][26][27], by UV irradiation [10,11,13,15,17,19,22,24], or by a chemical system [18,28,29].Up to now, most of the publications dealing with the development of monolithic columns are focused on the optimization of the composition of the polymerization mixture, changing factors such as the type of the monomer, the degree of cross-linking, the composition and concentration of the porogenic solvent, and the type of initiation. These variables have shown to have influence on porous properties of monoliths and consequently their chromatographic features.…”

“…Organic polymer-based monolithic columns including acrylamide-, acrylate-or methacrylate-, and styrenebased monoliths have highly favourable features, such as their chemical stability over the entire pH range, flexible modification of the supports, and good reproducibility [6][7][8][9]. Among these polymeric stationary phases, acrylate-[10-18] and methacrylate-based [19][20][21][22][23][24][25][26][27][28][29] monoliths are the most popular materials used for CEC applications. These polymeric monoliths are usually prepared by in situ polymerization of a mixture composed of functional monomer/s, cross-linker, porogens, and a free radical initiator.…”

Comparison of thermal‐ and photo‐polymerization of lauryl methacrylate monolithic columns for CEC

“…These phases are usually prepared via a free-radical polymerization of a mixture consisting of one or more functional monomers, including a cross-linker, in the presence of a porogenic solvent and an initiator. Polymerization reaction is usually initiated thermally [4][5][6][7][8][9] or by UVirradiation [6,7,[9][10][11][12][13], although other less common approaches such as the use of g-radiation [14,15] or chemical agents [16][17][18][19] have been described.…”