title: Studies on Behaviors of Interactions Between New Polymer-based ZIC-HILIC Stationary Phases and Carboxylic Acids.
abstract: Zwitterionic stationary phases with nearly identical capacities were prepared by graft polymerization of a series of sulfobetaine precursors onto the surface of porous PS/DVB particles. The different spacer lengths are used as an investigative tool for the retention behavior of carboxylic acids; namely malonic, succinic, glutaric and maleic acid. In zwitterionic ion chromatography-hydrophilic interaction liquid chromatography (ZIC-HILIC) separation mode, the retention characteristic of carboxylic acids was examined using sodium acetate/acetonitrile eluents and UV detection. The retention is based on partitioning in reversed as well as in HILIC mode and zwitterionic ion exchange resulting in a mixed separation mode for the carboxylic acids. This ion exchange behavior has never been observed before for sulfobetaine-based zwitterionic stationary phases.
authors.affiliation: Department of Chemistry, College of Science, University of Baghdad, Al-Jadriya campus, 10071 Baghdad, Iraq Ashraf_analytical@yahoo.com.
authors.forename: Ashraf Saad
authors.initials: AS
authors.lastname: Rasheed
authors.affiliation: Department of Chemistry, College of Science, University of Al-Nahrain, Al-Jadriya campus, 10072 Baghdad, Iraq.
authors.forename: Bashaer Abbas
authors.initials: BA
authors.lastname: Al-Phalahy
authors.affiliation: Faculty of Chemistry, University of Marburg, Hans-Meerwein-Str. 4, 35043 Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Seubert