A NEW ANALYTICAL CELL FOR CARBOHYDRATE ANALYSIS WITH A MAINTENANCE-FREE REFERENCE ELECTRODE

An electrochemical cell for carbohydrates that uses a completely maintenance-free reference electrode has been introduced. The cell consists of three electrodes: a gold working electrode, a stainless steel counter electrode, and a palladium reference electrode. Other fluid-path cell components are fabricated of PEEK, Kel-F, and Teflon. The solid state palladium reference electrode requires no filling solutions and hence has no additional junction potentials. This versatile, pH-sensitive reference electrode allows the cell to compensate for pH shifts in the gold working electrode. resulting in better reproducibility. The cell functioned well for more than 2700 injections of a glucose standard over 6 weeks without maintenance of any kind. The control module uses a three pulse waveform that allows for selectable potentials and pulse durations as well as an adjustable delay period prior to the acquisition of the analytical signal.