Electrochromatography on acrylate‐based monolith in cyclic olefin copolymer microchip: A cost‐effective and easy‐to‐use technology

Abstract

This article shows that there is great interest in using an electrochromatographic microchip made of hexyl acrylate (HA) based porous monolith cast within the channel of a cyclic olefin copolymer (COC) device. The monolith is simultaneously in situ synthesized and anchored to the inner walls of the channel in less than 10 min. By appropriate choice of light intensity used during the synthesis, the separation efficiency obtained for nonpolar solutes such as polycyclic aromatic hydrocarbons (PAH) is increased up to 250 000 plates/m. The performance of this HA-filled COC microchip was investigated for a wide range of analytes of varying nature. The reversed-phase separation of four aflatoxins is obtained in less than 2 min. The baseline separation of a mixture of neurotransmitters including six amino acids and two catecholamines is possible thanks to the superimposition of the differences in electrophoretic mobility on the chromatographic process. The durability of the system at pH 13 allows the separation of five biogenic amines and the quantitative determination of two of them in numerous wine samples. The feasibility of on-line preconcentration is also demonstrated. Hydrophilic surface modification of COC channel via UV-photografting with poly(ethylene glycol) methacrylate (PEGMA) before in situ synthesis of HA, is necessary to reduce the adsorption of very hydrophobic solutes such as PAH during enrichment. The detection limit of fluoranthene is decreased down to less than 1 ppb with a preconcentration of 4.5 h on the HA-filled PEGMA functionalized COC microchip.

Post‐polymerization modification of a new reactive monolith for reversed phase and hydrophilic interaction capillary electrochromatography of neutral, polar, and biologically active compounds

“…The surface charge density of the monolithic stationary phase can be controlled by changing the percentage of charge bearing monomer in the synthesis of polymer‐based media for CEC. AMPS is mostly used as a charge‐bearing monomer to generate strongly stable sulfonic acid moieties that remain completely ionized over a broad range of pH within the monolithic structure . In this study, poly(HPMA‐Cl‐co‐EDMA) capillary monoliths prepared with the HPMA‐Cl concentrations ranging between 30% and 60% v /v were used as a new reactive starting material to control the morphology and porous properties.…”

“…AMPS is mostly used as a charge-bearing monomer to generate strongly stable sulfonic acid moieties that remain completely ionized over a broad range of pH within the monolithic structure. [40][41][42] In this study, poly(HPMA-Cl-co-EDMA) capillary monoliths prepared with the HPMA-Cl concentrations ranging between 30% and 60% v/v were used as a new reactive starting material to control the morphology and porous properties.…”

Surface functionalization of cyclic olefin copolymer by plasma‐enhanced chemical vapor deposition using atmospheric pressure plasma jet for microfluidic applications

“…Moreover, surface functionalization of COC microchannels minimizes the adsorption of analytes in particular biological molecules . Nowadays, three main COC surface functionalization strategies are commonly used: ultraviolet (UV)/ozone oxidation, photografting, and plasma processes …”

“…Moreover, surface functionalization of COC microchannels minimizes the adsorption of analytes in particular biological molecules. [11,14,18,23] Nowadays, three main COC surface functionalization strategies are commonly used: ultraviolet (UV)/ozone oxidation, [24,25] photografting, [11,13,15,20,21,23,[26][27][28][29] and plasma processes. [16,19,[30][31][32][33][34][35][36] The UV/ozone oxidation procedure relies on the exposition of the COC surface under a mercury lamp and in an air-filled chamber at atmospheric pressure resulting in the generation of ozone.…”

Surface functionalization of cyclic olefin copolymer with aryldiazonium salts: A covalent grafting method

“…As a large amount of methacrylate monomers is available, COC surfaces progressively gained new functionalities including low protein adsorption, adjustable electroosmotic flow or immobilization of reactive groups ready to use with biomolecules. Some polymeric monoliths were photo-grafted in COC microfluidic channels to develop original analytical tools [23,29]. Different ways (phenanthroline, amine, reactive silane or alkyne azide chemistry) are suitable for grafting process [30][31][32].…”