title: Tunable temperature responsive liquid chromatography through thiolactone-based immobilization of poly(N-isopropylacrylamide).
abstract: A straightforward and efficient functionalization of aminopropylsilica with polymeric structures is described for the development of temperature responsive stationary phases applicable in purely aqueous liquid chromatography. The immobilization of the thermoresponsive polymers involves a thiolactone-based ring opening using the primary amines in aminopropylsilica, with a simultaneous one-pot, thiol-ene functionalization with an acrylate of choice. This mild, straightforward and modular grafting process results in high polymer coupling yields. By variation of the acrylate for the thiol-ene reaction, different stationary phases can be readily obtained. Two stationary phases as a result of the modular modification of aminopropylsilica were evaluated with test mixtures of hydrophobic analytes and a mixture of di- and tripeptides. Analyses using the 5μm material packed in 10cm×4.6mm columns revealed high hydrophobic retention, which proved adaptable as a function of the temperature in aqueous mobile phases. High versus low retention were obtained at temperatures above and below the lower critical solution temperature of the polymer, respectively. Moreover, the columns depict potential for diastereoisomeric peptide separation. Finally, the lower retention, observed when using PEGylated silica, illustrates the potential of the approach for modular stationary phase tuning.
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium. Electronic address: angel.satti@uns.edu.ar.
authors.forename: Angel J
authors.initials: AJ
authors.lastname: Satti
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Espeel
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Martens
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium.
authors.forename: Tim
authors.initials: T
authors.lastname: Van Hoeylandt
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium.
authors.forename: Filip E
authors.initials: FE
authors.lastname: Du Prez
authors.affiliation: Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research, Separation Science Groups, Ghent University, Krijgslaan 281 S4-bis, Ghent B-9000, Belgium. Electronic address: Frederic.Lynen@UGent.be.
authors.forename: Frederic
authors.initials: F
authors.lastname: Lynen
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D010455:Peptides / Q000737:chemistry; D012822:Silicon Dioxide; D012996:Solutions; D013237:Stereoisomerism; D013457:Sulfur Compounds / Q000737:chemistry*; D013696:Temperature; D014867:Water
chemical_list: D000180:Acrylic Resins; D010455:Peptides; D012996:Solutions; D013457:Sulfur Compounds; D014867:Water; C052970:poly-N-isopropylacrylamide; D012822:Silicon Dioxide
keywords: HPLC; Poly(N-isopropylacrylamide); Purely aqueous; Thiol-ene conjugation; Thiolactone