Abstract: An electroanalytical system useful for measuring analytes, such as sugar, sulfites, and ethanol in wine, includes a printed copper electrode in an alkaline medium, a flow injection system to contact very small samples with the copper electrode, current measurement to measure current flowing in a cell containing the copper electrode and a data processor connected to the copper electrode. The copper electrode has a copper oxide surface. Results are obtained by comparing known current flows for particular analytes with the flows obtained for the sample.