Principal components analysis of complex n.m.r. spectra from heterogeneous material

Principal components (PC) analysis is applied to raw data profiles of solid state 13C CP/MAS n.m.r. spectra of heterogeneous organic material. Information about various peat classes is obtained from component scores plots, where similar types of samples (Carex or Sphagnum peat) group together. Substructures in these groups that correspond to directions of increased decomposition are found. Component loadings are used to estimate spectra from peat constituents e.g. bitumen/humic substances and carbohydrates are uncovered in the first two loadings. This may be a good method to use in combination with other techniques, such as deconvolution and synthesis of spectra.