Discrimination and identification of different amines by pattern recognition of kinetic spectral data

Abstract

This study represents detection and differentiation of primary, secondary, tertiary, aliphatic and aromatic as well as linear and branched amines using kinetic absorption spectra and multivariate analysis. The approach utilizes the electron donor-acceptor (EDA) complex formation between amines (as electron donors) and iodine (as electron acceptor) in chloroform solution. The criteria for discrimination were shape and intensity of the time dependent spectra of the amine–iodine systems as well as the kinetics of the process. It was found that the time-dependent absorption spectra of the complex formed between different amines and iodine are sufficiently diverse to provide a signature for each of the amines used. Pattern recognition methods including principal component analysis (PCA), linear discriminate analysis (LDA) and quadratic discriminate analysis (QDA) were used to analyze the response patterns. Multidimensional spectral identification of a collection of 27 amines was successfully performed. The method was successful even for the identification of amines having close structural similarity.