In proteomics and biomedicine fast techniques applicable for preliminary tests of the protein properties and structural changes are sought. Methods of electrochemical analysis have been little utilized in these fields. We show that using constant current chronopotentiometric stripping peak H, minute amounts of denatured and reduced bovine serum albumin (BSA) can be easily discriminated from native BSA. Peak H, which is due to catalytic hydrogen evolution, is greatly enhanced in the presence of non-denaturing concentrations of guanidinium chloride. The course of BSA reduction and denaturation can be followed and traces of the damaged protein can be detected in native BSA samples. (C) 2007 Elsevier Ltd. All rights reserved.