Route of decomposition of thiomersal (thimerosal)

The route of formation and identification of the principal degradation prod ucts of thimerosal (thiomersal) has been undertaken. The initial oxidation to dithiosalicylic acid is followed by cleavage of the disulphide bond of t he dithiosalicylic acid by the ethylmercuric ion to reform 1.5 mol of thime rosal with concurrent oxidation to form 0.5 mol of 2-sulfinobenzoic acid fo r each mole of dithiosalicylic acid. In the presence of copper ions 2-sulfo benzoic acid was also formed. A mechanism has been proposed which accounts for the stoichiometry of the cleavage reaction observed and the significanc e of the reaction is discussed. (C) 2000 Elsevier Science B.V. All rights r eserved.