Parametric signal fitting of highly asymmetric voltammograms by using the exponentially modified Gaussian (EMG) function

• Exponentially modified gaussian fitting is applied to overlapping and asymmetric voltammograms.
• One of the adjustable parameters is the peak area, more reliable than the height in some situations.
• EMG function has been extensively applied to chromatograms but not to voltammograms.
• EMG method was validated with experimental data from the Cd(II)–cysteine system.

A new multivariate curve resolution method is proposed according to the parametric signal fitting (PSF) strategy for the analysis of overlapping and highly asymmetric voltammetric signals. The method is based on the fitting of the well-known exponentially modified Gaussian (EMG) function, which had been previously used for the resolution of coeluted chromatographic peaks. The main advantage of this function is that one of the adjustable parameters is just the area under the peak, which is a magnitude more reliable than the peak height in the case of electrochemical systems providing highly asymmetric voltammograms. After a preliminary test with simulated data, the proposed method has been successfully applied to the experimental system Cd(II)–cysteine in both mercury and carbon screen-printed electrodes.