The phase-inversion (PI) method was used to cast permselective cellulose acetate membranes on glassy carbon electrodes with the aim of suppressing protein interferences in anodic stripping voltammetry (ASV). By using cadmium and lead as test analytes and differential pulse ASV as detection method, it was found that the modification of the electrode greatly reduces the interference from albumin. Cellulose acetate membranes prepared by the PI method give better protection against protein interference and have more reproducible permeability characteristics than membranes of comparable thickness prepared by the base hydrolysis method. An optimization study of the PI coating procedure was undertaken.