title: Poly(alkylmethylsiloxanes) thermally immobilized on silica as stationary phases for high-performance liquid chromatography.
abstract: Poly(methyloctylsiloxane) (PMOS) and poly(methyloctadecylsiloxane) (PMODS) were sorbed onto porous HPLC silica and thermally immobilized, in the absence of radical initiators, at temperatures in the range of 80 to 180 degrees C. Following extraction of non-immobilized polymer the materials were packed into columns and their chromatographic properties evaluated. The shorter chain (PMOS) stationary phase showed good HPLC characteristics after thermal immobilizations up to 120 degrees C while the longer chain (PMODS) phase gave satisfactory HPLC phases following thermal immobilizations at 80 and 100 degrees C. Stability evaluation for the PMOS and PMODS columns immobilized at 100 degrees C required 250 ml of pH 8.5 mobile phase at 60 degrees C to significantly decrease efficiency, suggesting a long useful life time at neutral pH and ambient temperature.
authors.affiliation: LABCROM--Laboratório de Pesquisas em Cromatografia Líquida, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, CEP 13083-970 Campinas, SP, Brazil.
authors.forename: Carla B G
authors.initials: CB
authors.lastname: Bottoli
authors.forename: Zahra F
authors.initials: ZF
authors.lastname: Chaudhry
authors.forename: Dania A
authors.initials: DA
authors.lastname: Fonseca
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Collins
authors.forename: Carol H
authors.initials: CH
authors.lastname: Collins
mesh_terms: D000465:Algorithms; D000473:Alkanes / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide; D012833:Siloxanes / Q000737:chemistry*; D012997:Solvents; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D000473:Alkanes; D011108:Polymers; D012833:Siloxanes; D012997:Solvents; D012822:Silicon Dioxide