A microelectrode flow amperometric detector for water-soluble polymers

A single electrode assembly, consisting of a platinum wire (20- or 25-μm diameter) microelectrode and a palladium coating (as auxiliary/pseudo-reference electrode) on the glass tubing housing the microelectrode, 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 μg. The detector performance was superior to that of a differential refractive index detector in terms of limits of detection (sub-μg levels of polymer), baseline stability, and reproducibility of analytical signal.