Electrochemical evaluation of ultrasonic cleaning: the Galvani potential

We show that measurements of the Galvani potential between two titanium electrodes can give a quantitative on-line measure of ultrasonic cleaning efficiency. One titanium electrode is the reference (clean) electrode, and the other has adsorbed contaminant to be evaluated. The potential between them is read by using a high impedance millivoltmeter. The method is capable of detecting small fractions of protein or lipid monolayers, and is about as sensitive as the radioactive tracer technique to which it is compared. The Galvani potential method can only be used on a restricted number of electrode materials, including titanium, gold, platinum and vitalium, but not including stainless steel, nickel alloys or aluminium.