Determination of overlapping peaks heights by tangent method

Abstract

In this work the tangent approach is valid on example of overlapping voltammetric peaks of Cd (II) and Tl (I) at their different concentration in a mixture. Height of the frame plotted by inflectional tangents to the inflection points on peak branches is used as a peak maximum for calibration curve plotting. It is founded that systematic errors are not significant for the measurement of Tl (I) peak. In case of the Cd (II) peak the significant systematic error arising from tailing of the ascending part of Tl (I) peak is observed. We propose a method of systematic errors compensation. Systematic errors are estimated by peak series modeling. We use six parametric peak model with help of a priory information about signal shape and real values of resolution criteria and ratios of peaks heights. Peak shape is determined by difference method and ratios of peak heights by calibration curve.