Graphite-polystyrene composite with enhanced electrochemical and electroanalytical performance

ABSTRACT A new composite electrode (G-PSE) was developed from graphite powder and expanded polystyrene (EPS, Styrofoam) by simply dissolving the foam in chloroform, incorporating the graphite particles under mixing and volatilizing the solvent at 80 oC. The resulting rigid black composite can be softened with acetone and so it can easily be molded to any shape, e.g., into a PTFE tube with an electric contact, to build the electrode. A 75% graphite content (w/w) was found appropriate for preparing the G-PSE with a working potential similar to that of carbon paste electrodes, superior mechanical stability and a much faster response to ferrocyanide, close to reversible and similar to that of the much more expensive glassy carbon electrode. Applications of the G-PSE to dipyrone and paracetamol quantification in pharmaceutical formulations were demonstrated. The results accomplished by flow injection analysis with amperometric detection at the G-PSE were successfully validated against standards methods.