title: Stability studies of stationary phases from poly(methyltetradecylsiloxane) sorbed and immobilized onto metalized and unmodified silicas.
abstract: Stationary phases for RP-HPLC were prepared from metalized (titanized and zirconized) and unmodified silica particles using sorbed and immobilized poly(methyltetradecylsiloxane) (PMTDS). Different immobilization procedures, such as gamma irradiation and thermal treatments, were used for the preparation of the immobilized PMTDS phases. The stabilities of these stationary phases were evaluated by passing alkaline (pH 10) mobile phase through 60 mm x 3.9 mm columns of the different phases, with periodic tests to evaluate chromatographic performance. The results show that higher stabilities were obtained with stationary phases based on PMTDS immobilized on zirconized silica, these phases being 50% more stable than their titanized silica counterparts and 400% more stable than those based on unmodified silica. These supports provide higher chemical stability to the laboratory-made stationary phases, when compared with chemically bonded silica-based phases.
authors.affiliation: Instituto de Química, Universidade Estadual de Campinas, 13084-971 Campinas, SP, Brazil.
authors.forename: Anizio M
authors.initials: AM
authors.lastname: Faria
authors.forename: Edivan
authors.initials: E
authors.lastname: Tonhi
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Collins
authors.forename: Carol H
authors.initials: CH
authors.lastname: Collins
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002845:Chromatography / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D012822:Silicon Dioxide / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry* / Q000302:isolation & purification; D013997:Time Factors; D015040:Zirconium / Q000737:chemistry
chemical_list: D008670:Metals; D012833:Siloxanes; C513729:poly(methyltetradecylsiloxane); D002244:Carbon; D012822:Silicon Dioxide; D015040:Zirconium; C028541:zirconium oxide