Partial least squares method in the analysis by square wave voltammetry. Simultaneous determination of sulphamethoxypyridazine and trimethoprim

A comparison between the applicability of two multicomponent analysis methods, square wave voltammetry by PLS and adsorptive stripping voltammetry square wave by PLS, to the resolution of overlapping reduction peaks corresponding to the irreversible reduction processes of Sulphamethoxypyridazine (SMP) and its synergetic potentiator, Trimethoprim (TMP), has been performed. The results show that PLS has the capacity of modelling the total evolution of the Square Wave Voltammograms (SWV) and Adsorptive Stripping Voltammograms (SWAdSV) in the case of overlapping reduction peaks. The PLS multivariate calibration method has been successfully applied to the simultaneous analysis of both compounds in two veterinary formulations. These results were compared with those obtained by liquid chromatography (LC) with spectrophotometric detection.