title: Monolithic silica rods grafted with thermoresponsive anionic polymer brushes for high-speed separation of basic biomolecules and peptides.
abstract: Thermoresponsive anionic copolymer brushes, poly(N-isopropylacrylamide-co-acrylic acid-co-tert-butylacrylamide) [P(IPAAm-co-AAc-co-tBAAm)], were grafted onto a monolithic silica rod column through surface-initiated atom-transfer radical polymerization (ATRP) to prepare an effective thermoresponsive anionic chromatography matrix. An ATRP initiator was attached to the rod surface. N-Isopropylacrylamide (IPAAm), tert-butyl acrylate (tBA), tert-butylacrylamide (tBAAm), and the ATRP catalyst CuCl/CuCl2/tris[2-(N,N-dimethylamino)ethyl]amine were dissolved in 2-propanol, and the reaction mixture was pumped into the initiator-modified column. After grafting P(IPAAm-co-tBA-co-tBAAm) on the monolithic silica surfaces, deprotection of the tert-butyl group of tBA was performed. Chromatographic analysis showed that the prepared column was able to separate catecholamine derivatives and angiotensin subtypes within a shorter analysis time (5 min) than a silica-bead-packed column modified with the same copolymer brush could. These results indicated that the prepared copolymer-modified monolithic silica rod column may be a promising bioanalytical and bioseparation tool for rapid analysis of basic bioactive compounds and peptides.
authors.affiliation: Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University , TWIns, 8-1 Kawadacho, Shinjuku, Tokyo 162-8666, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nagase
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Hideko
authors.initials: H
authors.lastname: Kanazawa
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000327:Adsorption; D000809:Angiotensins / Q000302:isolation & purification; D002395:Catecholamines / Q000302:isolation & purification; D002845:Chromatography / Q000295:instrumentation* / Q000379:methods; D002850:Chromatography, Gel; D010455:Peptides / Q000302:isolation & purification*; D056951:Photoelectron Spectroscopy; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
chemical_list: D000178:Acrylamides; D000809:Angiotensins; D002395:Catecholamines; D010455:Peptides; D011108:Polymers; D012822:Silicon Dioxide; C067295:N-isopropylacrylamide; C115287:tert-butylacrylamide