The binding of metal Ions by mercaptoacids. II. Formation constants for the complexes of mercaptosuccinate with Cd(II) and computer simulation of its ability to mobilize the low molecular weight fraction of Cd(II) in blood plasma

Abstract

Formation constants for cadmium(II) complexes of mercaptosuccinate in aqueous solution have been determined at 37 °C and 150 mmol dm −3 chloride medium by potentiometric titrations using a glass electrode. The emf data obtained have been analyzed using the ESTA computer program library. The experimental data can be explained by the formation of the complexes Cd 3(MSA) 2, Cd 2(MSA) 2H −, Cd 2- (MSA) 2 2−, Cd 2(MSA) 2OH 3− and Cd(MSA) 2 4−. The formation constants obtained have been used in a simulation model of blood plasma to investigate the mobilization of cadmium(II) by mercaptosuccinate in normal plasma. It is shown that mobilization is unlikely at pharmacological levels of the drug.