D. Compagnone, D. O’Sullivan and G. G. Guilbault
An amperometric enzyme electrode for the determination of aspartame was developed by covalent immobilization of alcohol oxidase and α-chymotrypsin. A platinum based hydrogen peroxide electrode was used as the detector. Excellent sensitivity was obtained using batch, flow-through and flow injection methods with detection limits of 2 × 10-7, 4 × 10-7 and 10-6 mol l-1, respectively. Different strategies for eliminating interfering compounds, including the introduction of an additional alcohol oxidase–catalase membrane and signal subtraction using an alcohol electrode, were employed. A recovery study on seven food samples was carried out and the results were satisfactory.