Capillary electrophoresis in speciation analysis. Investigations of metal-polyaminopolycarboxylate complexes and effects of metals on proteins

Model substances of metal species composed of organic ligands and heavy metals were separated and detected by capillary electrophoresis. The effect of metal addition to polyaminopolycarboxylic acids on their electrophoretic mobility was studied. Metal-ligand complexation reactions changed the mobilities of polyaminopolycarboxylic acids which decreased their migration times (with the exception of nitrilotriacetic acid) and increased detection sensitivities. The separation time is less than 10 min. The use of this type of reaction in metal-protein speciation is described and demonstrated with both model protein mixtures and cereal protein extracts, based on studies of 11 metal ions.