Theoretical and experimental aspects of the response of stripping voltammetry in flow injection systems

The coupling of stripping voltammetry with flow injection systems offers significant advantages over conventional stripping methods. Equations solved for conventional stripping voltammetry, with steady-state deposition current, are not applicable to flow injection systems. Theoretical equations for the peak current under flow injection conditions are derived. As the total charge passed during the deposition step, ∫i dt, is independent of the shape of the sample plug, the stripping peak current is independent of the degree of dispersion. As a result, precise control of the dispersion or deposition period may not be required. The peak current is predicted to be directly proportional to the sample volume. Experimental results are incorporated to support the theoretical conclusions. The effects of experimental variables such as flow rate, length of tubing, deposition period, or sample volume are presented using cadmium ion as test species.