Resolving nuclear magnetic resonance data of complex mixtures by three-waymethods: Examples of chemical solutions and the human brain

Despite the use of hyphenated and/or high-resolution instruments in analyti cal spectroscopy, the resulting spectral data often represent mixtures of s everal components. When no reference data in the form of reference spectra or concentration profiles are available, self-modeling mixture analysis tec hniques can be utilized to obtain the spectra of the pure components and th eir concentration profiles, There are many different algorithms to resolve mixture spectra, and the mathematical procedures involved are not always si mple. This paper will discuss some of the aspects and problems of self-mode ling mixture analysis, with the focus on the three-way method and without g oing into the mathematical details. Practical examples will be shown of met hods applied to nuclear magnetic resonance data. The techniques discussed c an also be applied to magnetic resonance images and an example will be show n of the human brain. (C) 1999 Elsevier Science B.V. All rights reserved.