title: Selectivity comparisons of monolithic silica capillary columns modified with poly(octadecyl methacrylate) and octadecyl moieties for halogenated compounds in reversed-phase liquid chromatography.
abstract: Stationary phase selectivities for halogenated compounds in reversed-phase HPLC were compared using C18 monolithic silica capillary columns modified with poly(octadecyl methacrylate) (ODM) and octadecyl moieties (ODS). The preferential retention of halogenated benzenes on ODM was observed in methanol/water and acetonitrile/water mobile phases. In selectivity comparison of selected analytes on ODM and ODS, greater selectivities for halogenated compounds were obtained with respect to alkylbenzenes on an ODM column, while similar selectivities were observed with a homologous series of alkylbenzenes on ODM and ODS columns. These data can be explained by greater dispersive interactions by more densely packed octadecyl groups on the ODM polymer coated column together with the contribution of carbonyl groups in ODM side chains. For the positional isomeric separation of dihalogenated benzenes (ortho-, meta-, para-), the ODM column also provided better separation of these isomers for the adjacently eluted isomers that cannot be completely separated on an ODS column in the same mobile phase. These results imply that the ODM column can be used as a better alternative to the ODS column for the separation of other halogenated compounds.
authors: Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
authors: Wasura
authors: W
authors: Soonthorntantikul
authors: Natchanun
authors: N
authors: Leepipatpiboon
authors: Tohru
authors: T
authors: Ikegami
authors: Nobuo
authors: N
authors: Tanaka
authors: Thumnoon
authors: T
authors: Nhujak
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D001555:Benzene Derivatives / Q000032:analysis; D002733:Chlorophenols / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006846:Hydrocarbons, Halogenated / Q000032:analysis*; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014050:Toluene / Q000032:analysis
chemical_list: D000097:Acetonitriles; D001555:Benzene Derivatives; D002733:Chlorophenols; D006846:Hydrocarbons, Halogenated; D011109:Polymethacrylic Acids; C527028:poly(octadecyl methacrylate); D014050:Toluene; D012822:Silicon Dioxide; D000432:Methanol; C032159:acetonitrile