Application of wavelet transform in pulsed ultrasonic modulation voltammetry

In this study, wavelet transform was employed to achieve the different current components in pulsed ultrasonic modulation voltammetry. It was found that the pulsed sonovoltammograms could be decomposed into wavelet approximations and wavelet details by projecting wavelet transform on the signals in question. Since wavelet approximations with a certain scale parameter may retain the waveform of the original signal, the current components resulted from ultrasound “on” and “off” in pulsed sonovoltammograms could be separated at a certain scale parameter in multiplying wavelet approximation. With this method, the current components corresponding to pulse-on and pulse-off can be recorded separately without the external data acquisition system used in general modulation voltammetric measurements. The current difference between the two states was found to be proportional to the concentration of the electroactive species. The analytical usefulness of this approach was exploited for determination of ferrocyanide ion at sub-micromolar concentrations.