Resolution of overlapped electrochemical peaks with the use of the Kalman filter

Abstract

A major limitation in the use of electrochemical techniques for the quantitative analysis of mixtures is the difficulty of resolving overlapped peaks. This problem is further complicated by the low signal-to-noise ratios often encountered in trace analysis and by the use of electrochemical techniques that produce broad, asymmetric waveforms. This paper demonstrates the use of the Kalman Filter for multi-component analysis of linear sweep voltammograms. Even with the broad, asymmetric LSV waveform, synthetic data runs show that a peak separation of as little as 2.5 mV is sufficient for peak deconvolution in the presence of random noise. Besides separating overlapped peaks, the methods also filters the noise from the signal and can be used to separate the capacitive current component from the faradaic current component. The method is validated further using the Cd(II)/In(III) and Cd(II)/In(III)/Pb(II) systems which show peak separations of 40 to 200 mV. The use of the techniques with two other voltammetric waveforms is also demonstrated.