Determination of salicylic and gentisic acids in the presence of each other by matrix isopotential synchronous fluorescence spectrometry

Abstract

The determination of salicylic and gentisic acids in the presence of each other was performed by means of a novel spectrofluorimetric technique. The technique is useful for the determination of compounds in samples with unknown background fluorescence, and consists in performing synchronous scans through a trajectory joining points of equal intensity in a three-dimensional spectrum of the fluorescent matrix. The technique, referred to as matrix isopotential synchronous fluorescence spectrometry, can be improved by the application of derivative methods. Good results, both in terms of sensitivity and reproducibility, were obtained in the determination of salicylic and gentisic acids in the presence of each other by using this technique.