Multivariate Curve Resolution Methods Illustrated Using Infrared Spectra of an Alcohol Dissolved in Carbon Tetrachloride.

• Autores: Bjorn Grung, Egil Nodland, Geir Martin Forland
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 84, Nº 7, 2007, págs. 1193-1200
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Methods of curve resolution are new tools to meet the demands of effective data analysis in the modern analytical laboratory. Here, we present one way of resolving a data set typical for the chemical laboratory. To illustrate the necessary steps in a successful curve resolution, infrared spectra of an increasing concentration of 1-octanol in carbon tetrachloride are used. The IR spectra change dramatically as the alcohol self-associates and form various types of hydrogen-bonded aggregates. We present a model containing three different alcohol species. The species represent free alcohol monomers, open-chain oligomers, and cyclic oligomers. The number of non- and hydrogen-bonded species giving a unique contribution to the spectral variance is found using chemical rank analysis. The rank analysis is performed on the complete data matrix, as well as on the most interesting regions of the data. This enables the decomposition of the data matrix into spectral and concentration profiles for each species present. The resolution was performed using eigenstructure tracking analysis followed by alternating least squares.