title: Preparation of a new C18 stationary phase containing embedded urea groups for use in high-performance liquid chromatography.
abstract: A new C18 urea stationary phase was prepared by a single-step modification process through the reaction of ProntoSil spherical silica (3 microm, Bischoff) with the trifunctional alkoxysilane (CH3CH2O)3-Si-(CH2)3-NH-C(O)-NH-(CH2)17-CH3, prepared in our laboratory. The phase was characterized by elemental analysis and solid-state 29Si and 13C nuclear mangnetic resonance spectrometry. Chromatographic evaluations of the new phase in 150 x 3.9 mm HPLC columns involving the separation of different test mixtures, indicate good performance for both polar and basic mixtures and also show promising results for further applications.
authors.affiliation: Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13083-970 Campinas, São Paulo, Brazil.
authors.forename: César Ricardo
authors.initials: CR
authors.lastname: Silva
authors.forename: Stefan
authors.initials: S
authors.lastname: Bachmann
authors.forename: Renata Rabelo
authors.initials: RR
authors.lastname: Schefer
authors.forename: Klaus
authors.initials: K
authors.lastname: Albert
authors.forename: Isabel Cristina Sales Fontes
authors.initials: IC
authors.lastname: Jardim
authors.forename: Claudio
authors.initials: C
authors.lastname: Airoldi
mesh_terms: D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D004364:Pharmaceutical Preparations / Q000302:isolation & purification; D012822:Silicon Dioxide; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014508:Urea / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D008024:Ligands; D004364:Pharmaceutical Preparations; D012997:Solvents; D012822:Silicon Dioxide; D014508:Urea