title: Kinetic simulation of complex decomposition as a tool for the ion chromatographic determination of elemental speciation of less inert metal ions.
abstract: Species decomposition is an often occurring artefact during the chromatographic determination of elemental speciation. The decomposition follows a simple path to lower coordinated compounds. Therefore a simulation is developed for those decomposition reactions. The simulation separates the isochronal processes of the separation itself and the ongoing reaction and delivers thermodynamic and kinetic information about the species present in the original sample. This shifts the boundaries of separation based elemental speciation to less inert metal ions which are typically not analyzable by this approach. The less inert gallium monooxalato complex [GaOx](+) is used as example for testing the simulation software as this complex decomposes only to Ga(3+) and both species are retained on cation exchange columns. We extracted thermodynamic and kinetic information from flow rate experiments by the analysis of the peak areas in the chromatogram. The results show that some of our assumptions such as the irreversibility under the applied chromatographic conditions are not ultimately true, but good accordance of simulation and measured data was achieved.
authors.affiliation: Philipps-University Marburg, Faculty of Chemistry, Analytical Chemistry, D-35032 Marburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Winter
authors.affiliation: Philipps-University Marburg, Faculty of Chemistry, Analytical Chemistry, D-35032 Marburg, Germany. Electronic address: seubert@staff.uni-marburg.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Seubert
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002845:Chromatography; D003198:Computer Simulation; D007477:Ions / Q000032:analysis* / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*
chemical_list: D007477:Ions; D008670:Metals
keywords: Chelating agents; Dynamic liquid chromatography; ICP-MS; Ion exchange chromatography; Labile analytes; Less inert metal complexes; Online coupling; Simulation; Trivalent metal ions