Fourier transform methods allow custom-designed complex waveforms to be used in ac voltammetry. Commonly a single wave or sum of sine waves of variable angular frequency (omega) but constant amplitude (Delta E) superimposed onto a dc ramp are employed. In the present case, a custom-designed waveform consisting of a combination of eight sine waves is introduced, with the property that each sine wave within the composite waveform has the property Delta E-i proportional to 1/root omega(i) where i represents the ith sine wave. Frequencies (and amplitudes) employed in a single experiment cover the range from 34.94 Hz (20 mV) to 1970.01 Hz (2.66 mV). Reversibility, is readily detected via use of this designer waveform by noting a constant peak height (I-p(omega t)) for all eight frequencies, whereas I-p(omega t) values decrease in a characteristic manner with increasing frequency for a quasi-reversible process or when uncompensated resistance is present, as demonstrated experimentally and theoretically. Importantly, background charging current contributions do not increase to a level that makes measurement of faradaic current difficult at high frequencies and hence charging current is readily corrected for over the entire frequency range of interest. (C) 2009 Elsevier B.V. All rights reserved.