Quantitative structure-mobility relationship modelling of electrokinetic chromatography of metal complexes: approaches and limitations.
A charged surfactant or an ionic polymer added to the capillary electrolyte introduces micellar solubilization and ion-exchange interactions, respectively, as a supplementary separation principle for metal complexes among a great many other analytes. Acting as a pseudostationary phase, such electrolyte additives make the separation mechanism fairly different from that based only on differences in electrophoretic mobility. A range of quantitative structure-mobility relationships were developed to explain the migration behavior of metal complexes in micellar and ion-exchange electrokinetic chromatographic systems as a function of their primary structural parameters. The validity of migration models tested using a comprehensive selection of experimental data available in the literature was shown to depend significantly on the judicious choosing of the analyte structural descriptors and on the dominance of either of the electrophoretic mobility of the analyte, partitioning into the micelle, and the ion-exchange interaction with the polymer. In the systems where the separation mechanism is dominated by neither chromatography nor electrophoresis, their relative contributions were accounted for by the degree of correlation between experimental and calculated mobilities and by variations in the absolute value and sign of regression coefficients at the most influencing parameters.
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow, Russia. rtimer@online.ru
Andrei R
AR
Timerbaev
Olga P
OP
Semenova
Oleg M
OM
Petrukhin
D002852:Chromatography, Ion Exchange / Q000379:methods; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D008670:Metals; D008958:Models, Molecular; D013501:Surface-Active Agents
D008670:Metals; D013501:Surface-Active Agents