A new type of tubular detector with platinum auxiliary electrode inside the silver amalgam tube (TD+AuxE) was proposed, fabricated, tested and compared with a typical silver amalgam tubular detector developed earlier. Non-stop-flow differential pulse voltammetric anodic stripping method (AS-DPV) and amperometric method in a glucose oxidase biosensor arrangement were tested.
Both detectors were applied for AS-DPV detection in flow systems for the first time. Solutions of zinc and cadmium cations were used as the testing species for voltammetry, and detection of oxygen concentration was used for amperometry.
All these experiments require application of highly negative potentials, which is possible to realize with detectors made of silver solid amalgam. The proposed combination of TD+AuxE provides a much greater current response than the arrangement with three individual electrodes.
All relevant parameters were optimized for the developed TD+AuxE. The simple and fast measuring protocol for the determination of the zinc content in commercial food supplement tablets has been developed.