A MICROELECTRODE FLOW AMPEROMETRIC DETECTOR FOR WATER-SOLUBLE POLYMERS

A single electrode assembly, consisting of a platinum wire (20- or 25- mu m diameter) microelectrode and a palladium coating (as auxiliary/ps eudo-reference electrode) on the glass tubing housing the microelectro de, has been utilized as a flow amperometric sensor for water-soluble polymers. An ordinary 3-V dry cell was used as voltage source. Amounts of injected polymer were in the range 0.01-260 mu g. The detector per formance was superior to that of a differential refractive index detec tor in terms of limits of detection (sub-mu g levels of polymer), base line stability, and reproducibility of analytical signal.