Preparation and characterization of sorbed and microwave immobilized HPLC stationary phases of poly (metilfenilsiloxane) on silica

Author(s)

Livia Maria Andrekowisk Fioravanti

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2007-11-28

Examining board members

Isabel Cristina Sales Fontes Jardim; Tania Akiko Anazawa; Susanne Rath

• Advisor: Isabel Cristina Sales Fontes Jardim

Abstract

In high performance liquid chromatography (HPLC), the column is one of the most important components of the chromatographic system, because it is in the column that the separation occurs. In this way, the search for stationary phases (SP) able to achieve separations with high efficiency has been a constant in many research laboratories. Phenyl substituted polysiloxanes have been used extensively in gas chromatography, but their application in HPLC has received little attention. This work presents the development of stationary phases for use in HPLC by immobilization of poly(methylphenylsiloxane) by microwave radiation on a silica support. The SP were characterized by physiochemical and chromatographic tests. Microwave radiation was chosen because it appears to be promising and has been little studied for SP immobilization. The best conditions of radiation were chosen using an experimental design, with the microwave power and the radiation time that provided phases with the best chromatographic performance, these being 720 W and 70 minutes. In these conditions, the SP showed high efficiency (78000 plates m), symmetrical peaks (asymmetry factor between 0.9 and 1.2) for nonpolar and basic compounds and good separation for the compounds analyzed. The chromatographic parameters show that microwave radiation improved the performance of the SP and provided an increase in stability in alkaline mobile phases. Besides, it provided a good polymer cover on silica surface, being a promising SP for the separation of neutral and basic aromatic compounds, such as pharmaceuticals with nitrogen groups and agrochemicals (AU)