Electrochemical identification of bronze corrosion products in archaeological artefacts.: A case study

The electrochemical response of the products of bronze corrosion is studied upon sample attachment to paraffin-impregnated graphite electrodes immersed into phosphate buffer. Characteristic square wave voltammetic profiles were obtained for CuCO(3), CuCl, Cu(2)O, CuCl(2) center dot 2H(2)O, azurite, malachite, atacamite and clinoatacamite. Application to real microsamples from a montefortino bronze helmet from Requena ( Valencia, Spain) dated back to the Second Iron Age reveals the presence of different corrosion products, namely, cuprite, nantokite, and atacamite-type materials. Data obtained from voltammetric and energy dispersive X-ray microanalysis in the samples extracted from different corroded zones of the helmet were in good agreement.