Fast Sweep Differential Pulse Voltammetry at a Dropping Mercury Electrode

By decreasing the pulse duration to well below that usually used In pulse voltammetry, the technique of fast sweep differential pulse voltammetry synchronized to a dropping mercury electrode has been developed. Digital electronic circuitry Is employed to control the pulse duration time. For cadmium In 1 M KNO₃ under optimum conditions, a limit of detection of 10^-8 M was obtained and, at the 4 × 10^-7 M level, a reproducibility of better than 1 % was found. Scan rates up to 200 mV/sec were used in the present work and comparison of results with existing theory is given. Analytically the method should be applicable to a wide range of systems and combines the advantages of high sensitivity, reproducibility, and excellent resolution and is considered superior to equivalent dc linear sweep methods.