Open thin-layer cell—A flow-through electrode for potentiometric stripping analysis

Abstract

An electrochemical flow-through cell is described that is substantially different from all conventional cells. It has an open structure and is made from a piece of Plexiglass that contains the working and auxiliary electrodes. The flow channel is replaced by a strip of filter paper, which adheres to the cell body and covers the inlet hole and both electrodes. The carrier solution is therefore precisely directed along the filter strip, which dips into the waste reservoir containing the SCE.

Potentiometric stripping analysis (PSA) was used to evaluate the performance characteristics of the cell in terms of flow-rate, injection volume and carrier composition. Linear calibration graphs were obtained in two concentration ranges (10–500 µg l^–1 and 1–10 mg l^–1) for Cd, Pb and Cu under slightly different experimental conditions. The practical advantages and the long-time response stability of the cell were demonstrated by the PSA determination of Zn in tap water. In the range 0.1–20 mg l^–1 a sample throughput of 120 h^–1 is obtainable with a reproducibility better than 5%.