Self-modelling curve resolution analysis of synchronous fluorescence spectroscopy data for characterization of acid mixtures and study of acid–base equilibria

Abstract

Aqueous solutions of carboxylic acids and phenols at micromolar concentration levels were analysed by synchronous fluorescence (SyF) spectroscopy. A strategy, based on provoking controlled variations in SyF spectra by changing the pH and treating spectral data by evolving factor analysis with specific concentration constraints, was developed and evaluated to extract information from the SyF data to determine acid–base parameters for simple acids and mixtures. The procedure was tested on an aqueous mixture of salicylic acid, caffeic acid and catechol as well as on pure solutions of these and other acids.