Asymmetric logistic peak as a suitable function for the resolution of highly asymmetric voltammograms in non-bilinear systems

Abstract

The asymmetric logistic peak is tested as a new function for the parametric signal fitting (PSF) of highly asymmetric electrochemical signals in non-bilinear datasets, such as those obtained in linear sweep voltammetry (LSV) or in the presence of irreversible electrochemical processes. This new multivariate curve resolution strategy (PSF-ALPA) is successfully applied to LS voltammograms measured for the Cd(II)-glutathione system with a hanging mercury drop electrode, where Cd(II) is reversibly reduced, and to differential pulse voltammograms (DPV) measured at a glassy carbon electrode, where Cd(II) reduction becomes irreversible. Matrix augmentation by using LS voltammograms measured at different scan rates provides good results and encourages the development of ALPA methodology for third order data.

Approximate calculation of voltammetric peak of diffusionless system

“…Such a numeric approach helps to perform peaks separation, background correction, and may be regarded as an effective signal filtering. Peaks affected by diffusion limitations have asymmetric shape and requires elaborated numerical models . Voltammetric peaks of adsorbed systems are symmetrical, but simulation of these peaks is complicated by lateral interactions.…”

MATLAB in electrochemistry: A review

“…The asymmetric logistic peak adjustment (ALPA) was developed as a new function for the PSF of highly asymmetric electrochemical signals in non-bilinear datasets or in the presence of irreversible electrochemical processes [63]. Fig.…”

“…Some of the main differences among them are as follows: (1) whether alignment is performed using the continuous signal or individually detected peaks, (2) whether or not signal intensity is used, and (3) whether or not scale changes are corrected. The most important alignment methods that have been employed for aligning the voltammograms are COW, icoshift, GPA, GPA2D, ALPA, shiftfit and pHfit [58][59][60][61][62][63]65,83,116,117,119,120].…”

A perspective on the growth of chemometrics in Iran: a glance into activities between 2005 and 2012

“…After holding 11 AICWs, significant progress has been achieved towards the two main goals of its foundation. Today, many Iranian chemists (especially analytical chemists) are familiar with chemometrics methods, and Iranian chemometricians have scientific collaborations with different chemometrics research groups around the world [3,4,6,[8][9][10][11][12][13][14][15][16][17][18][19][20]. Some of expert chemometricians have visited Iran.…”