Multicomponent analysis in the wavelet domain of highly overlapped electrochemical signals: Resolution of quaternary mixtures of chlorophenols using a peg-modified Sonogel–Carbon electrode

Abstract

Chemometric methods have been applied to resolve mixture of phenols; phenolic compounds are amongst the most interesting chemical species from an environmental viewpoint. However, the number of papers that apply multivariate calibration methods to resolve electroanalytical signals of mixture of phenols is low. In this paper, we propose a new chemometric methodology to resolve, in the wavelet domain, quaternary mixtures of chlorophenols: 4-chloro-3-methylphenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol, in a concentration range from 0.05 to 0.25 mg·L − 1 , using differential pulse adsorptive stripping voltammetry (DPAdSV) as the electrochemical technique, and a new polyethylenglycol-modified Sonogel–Carbon electrode. The results obtained after applying a Fast Wavelet Transform (FWT)-based feature selection algorithm, coupled with different multivariate calibration methods (multilinear regression-MLR and partial least squares regression-PLS) are compared with those obtained from a direct PLS. Besides, an Orthogonal Signal Correction (OSC)-based Calibration Transfer procedure (OSC-CT) is also applied, as a pre-processing tool, in order to improve the results obtained with the previous techniques.