DETERMINATION OF AMALGAM-FORMING METALS BY ANODIC-STRIPPING VOLTAMMETRY IN SOLUTIONS CONTAINING DISSOLVED-OXYGEN

Amalgam-forming metals can be determined by anodic stripping voltammetry in solutions containing dissolved oxygen. The procedure uses a modified mercury film electrode prepared by deposition of mercury on the surface of a silica-gel/carbon composite electrode. Between determinations the film is removed from the electrode surface either mechanically or by a potential pulse. Lead was determined over the concentration range from 0.01 to 250-mu-M, with relative standard deviation values not exceeding +/- 5%. The method was applied for the determination of metals in used motor oil.