Preparação de fases estacionarias para CLAE a partir de poli(metiloctilsiloxano) sobre a silica titanizada

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

This work investigated the process modification of a silica surface by titanium oxide followed by the sorption and immobilization of poly(methyloctylsiloxane) (PMOS) for use as stationary phase in high performance liquid chromatography, with special applications in alkaline mobile phases. The chromatographic support of titanized-silica was obtained by the chemical reaction of 10 mm porous silica with two different reagents: titanium tetrabutoxide or titanium tetrachloride. After the deposition of polymer by evaporation and immobilization using gamma radiation, the excess of liquid stationary phase was extracted with CH2Cl2. The support and the stationary phases were characterized by X-ray fluorescence, X-ray photoelectron spectroscopy, thermogravimetric analysis, elementaI analysis for carbon, infrared spectroscopy, density measurements, Si nuclear magnetic resonance and specific area. The chromatographic columns were optjmized with stationary phases having initial loading of 50 % PMOS followed by gamma radiation for immobilization and extraction with dichloromethane utilized at 0.3 mL min with MeOH:H2O as mobile phase. Tests of stationary phase stability up to 10000 the column volumes using MeOH:NaOH(aq) at the pH 7, 9, 12 and 13 showed that the gamma radiation stabilized the liquid stationary phase onto the chromatographic support. The extraction with dichloromethane after the irradiation led to better values of asymmetry and efficiency . The basic solutes present in the various samples were separated in either neutraI or basic mobile phases, indicating the perspective that a stationary phases based on titanium modified silica may be used for separations where alkaline mobile phases are required.

ASSUNTO(S)

cromatografia liquida silica quimica inorganica

ACESSO AO ARTIGO

Documentos Relacionados