Oscillating flow injection stripping potentiometry

A fully computerized flow injection (FI) manifold with a peristaltic pump allowing periodic alternation of the flow direction and incorporating a detector system capable of performing potentiometric stripping analysis (PSA) is outlined. The measuring technique has been named oscillating flow injection stripping potentiometry (OFISP). It combines the attractive features of both traditional flow injection analysis (FIA) and batch PSA and at the same time overcomes some of the most serious drawbacks of the latter resulting from the fact that potentiostatic deposition and chemical stripping occur in the same solution. An experimental study of the influence of the main parameters of the flow system on its behaviour was performed using Cu(II) solutions in the μg l−1 concentration range as samples. The potentiostatic deposition was carried out on an Hg precoated glassy carbon electrode and Hg(II) ions were utilized as oxidant in the chemical stripping step.