Comparison of detector systems in oxidative stripping potentiometry

Abstract

For oxidative stripping potentiometry (OSP) measurement, the achievement of reliable results is highly dependent upon the transport of oxidant to the electrode surface and, as a consequence, careful hydrodynamic control is crucial for reproducibility. Two types of detector system, batch and flow, with three different electrode systems, a standard voltammetric magnetic stirrer cell assembly, an voltammetric cell with optically controlled stirrer and a thin layer flow cell with peristaltic pump were compared. In the sensitivity studies, the static stripping procedure enhanced the sensitivity of the measurement compared to forced convection stripping. The use of a flow cell and peristaltic pump provided all the flexibility needed for OSP measurement. The sensitivity can be improved using the combination of fast deposition and slow stripping flow rates. From the viewpoint of reproducibility of the signals, excellent results were obtained for the use of the flow cell with peristaltic pump.