The potentiodynamic polarization using PIGE - testing of a method that helps identify historical metallic materials

The potentiodynamic polarization using a paraffin impregnated graphite electrode (abbreviated as PIGE) is an analytical electrochemical method suggested as an alternative to commonly used procedures of identification of historical metallic materials. The principle of the method consists in potentiostatic reduction of a small amount of the sample's corrosion products deposited on a PIGE and subsequent potentiodynamic oxidation of the reduced metals. The obtained potential/current density potentiodynamic curve is the starting point for determination of a metal present in the alloy (based on peaks' positions on the curve). The aim of the study was to test the methodology for identification of historical metallic materials and to monitor parameters that might impact the results of the analysis (polarization rate, size of particles, electrolyte de-aeration). The study also aimed to test suitability of the method for a quantitative analysis. Having applied the procedure on selected samples of alloys (solder and copper alloys), traces of silver, copper, tin and lead were identified in the samples, however, the possibility of using the method for quantitative analysis was not proven.