Principle of AC voltammetry:

A basic expression for peak current

i_p = K.n² .E_~ f² . ca

where, i_p = peak current, K = constant, E_~ = amplitude of superimposed AC, ca = concentration of the analyte, n = number of electrons, and F = frequency

Therefore, the height of AC polarographic peak can be used to determine the concentration in a way same to DC polarographic method. AC polarographic peak currents are hugely dependent on the kinetics of charge transfer reaction and the signals of strongly irreversible processes are suppressed. To reversible processes the half width of the peak b½ = 90/ n (mv) depends on the electron exchange as a result of that, for huge value of n, b will be narrower and along with slow processes, b will be broader.

AC polarographic denotations are limited to a sensitivity of about 10^-5 mol/dm³ because of high capacitance current contribution which is the main source for periodic charging and discharging of double layer.