Preparation of a new C18 stationary phase containing embedded urea groups for use in high-performance liquid chromatography

A new C18 urea stationary phase was prepared by a single-step modification process through the reaction of ProntoSil spherical silica (3 μm, 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 150×3.9 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.