6533b7d6fe1ef96bd126640b

RESEARCH PRODUCT

H-Point Standard Addition Method Applied to Voltammetry of Microparticles. Quantitation of Dyes in Pictorial Samples

subject

description

A solid-state electrochemical application of the H-point standard addition method (HPSAM) for quantifying two electroactive compounds, A, B, that produce strongly overlapped voltammetric peaks is described. It is based on peak current measurement in square-wave voltammograms recorded for solid samples containing a reference compound R, upon additions of a A- (or B-) containing standard compound. The method allows to the determination of the mass fraction of A and B by applying the H-point standard addition method to solid state voltammetry. The quotients between the currents measured at two selected potentials and the peak current of R vary linearly with the mass ratio of the added standard and the reference compound, thus providing an electrochemical method for determining the content of A and B in the sample avoiding matrix effects. The method is applied to the simultaneous determination of alizarin and purpurin in madder pigments and pictorial specimens using morin as a reference material.