Application of a new multivariate curve resolution procedure to the simultaneous analysis of several spectroscopic titrations of the copper(II)—polyinosinic acid system

The acid-base properties and the copper(II)-complexing behaviour of the polynucleotide polyinosinic acid have been studied by means of potentiometric and spectrophotometric titrations. Spectrophotometric data have been treated with a new multivariate curve resolution procedure that allows to analyze simultaneously different sets of spectroscopic titrations of the same multi-equilibria system. The results obtained give a real proof of the advantages of the proposed procedure over the single titration analysis: intensity ambiguities are eliminated, as well as rotational ambiguities if the information yielded by at least one of the titrations is selective.