Differential pulse voltammetry:

A higher detection limit in this technique is due to superior discrimination against charging current and impurity Faradaic current.

A peak current in differential pulse polarography is given by

where, i_p = Peak current, n = Number of exchanged electrons, F = Faraday constant, R = Gas constant, T = Temp. In Abs. Scale, A = Electrode surface area, C_a = Concentration of the analyte, ? E_A = Pulse amplitude, D = Diffusion coefficient of the analyte, and t_p = Pulse duration.

The detection limit for the determination by this technique is similar to square wave polarography at 10^-7 - 10^-8 mol/dm³. Other than for irreversible reaction it is lowered.

Figure: Pulse application measuring procedure and current potential curves for (a) Normal pulse voltammetry; and (b) Differential pulse voltammetry