MULTIVARIATE CURVE RESOLUTION APPLIED TO CONTINUOUS-FLOW SPECTROPHOTOMETRIC TITRATIONS - REACTION BETWEEN AMINO-ACIDS AND 1,2-NAPHTHOQUINONE-4-SULFONIC ACID

A continuous-now acid-base titration system has been developed for the study and analytical application of chemical reactions between amino acids and 1,2-naphthoquinone-4-sulfonate. For each titration, a set of spectra are obtained at pH values from 6.5 to 12.5. Multivariate curv e resolution is applied to provide an optimal estimation of concentrat ion and spectra profiles of the species formed during the chemical rea ction. Resolution of these chemical species is greatly improved when s everal runs of different spectrophotometric titrations of the same che mical reaction system (multiple correlated data matrices) are analyzed simultaneously, allowing the quantitative determination of the concen tration of amino acid that has reacted in each case.