DETERMINATION OF SMALL AMOUNTS OF ANALYTES IN THE PRESENCE OF A LARGEEXCESS OF ONE ANALYTE FROM MULTIANALYTE GLOBAL SIGNALS OF DIFFERENTIAL-PULSE VOLTAMMETRY AND RELATED TECHNIQUES WITH THE SIGNAL RATIO RESOLUTION METHOD

The signal ratio resolution method was applied to the determination by differential-pulse voltammetry and related techniques of two analytes in presence of a large excess of a third analyte in ternary mixtures of known qualitative composition. Using the signal ratio resolution me thod; a global signal is divided by the individual signal of the major component, multiplied by a factor, in order to obtain a height as clo se as possible to the estimated contribution of the major component to the global Signal, To establish possible influence of resolving the s ignal on the quantification, simulated differential-pulse polarograms (DPPs) were divided by the individual major component DPP having a dif ferent peak current height and different current translation values, U sing theoretically simulated DPPs, it was found that two minor compone nts can be determined with a relative error <1% for different resolvin g parameters (peak current height of resolving functions, current tran slation values and peak separations), The method was then verified on a system containing Cd at 0.3, Tl at 200 and Pb at 0.5 mu mol l(-1) us ing differential-pulse anodic stripping voltammograms. It was shown th at using this method and a system with favourable reversibility and am algam formation, cadmium can be determined in a 200-fold add lead in a 120-fold excess of thallium, with a relative error of deconvolution m ethods is the removal of the contribution of one component from the gl obal signal, revealing the contributions of the other components in a peak-shaped form that is linearly proportional to the analyte concentr ations.