Quantitative structure-retention relationships in capillary electrophoresis of inorganic cations and beta-adrenolytic and sulfonamides compounds

Quantitative structure-(electrophoretic) retention relationships (QSRR) were determined for metal cations using ionic radius, atomic mass and ionization energy as structural parameters. The QSRR show that atomic mass, A(m), can be treated as a descriptor of differences of electrophoretic retardation of inorganic cations. A(m) is a measure of the effective surface area of the solutes. The ionic radius of metals, I-r, accounts for the effective charge of a solute. The ionization energy, E(i), provides a correction to I-r with regard to solute charge. High predictive potency of QSRR and direct access to the required descriptors allow for the application of the approach in identification of individual components of mixtures of metals. In case of the capillary electrophoretic parameters of organic solutes molecular mass is a most significant retention descriptor identified. It can be considered a first approximation of the electrophoretic retardation factor. Further progress in QSRR in capillary electrophoresis of drugs requires reliable descriptors of effective charge of organic solutes.