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Analytical and Bioanalytical Chemistry

, Volume 407, Issue 4, pp 1089–1095 | Cite as

Application of R-mode analysis to Raman maps: a different way of looking at vibrational hyperspectral data

  • Alois Bonifacio
  • Claudia Beleites
  • Valter Sergo
Research Paper

Abstract

Hierarchical cluster analysis (HCA) is extensively used for the analysis of hyperspectral data. In this work, hyperspectral data sets obtained from Raman maps were analyzed using an alternative mode of cluster analysis, clustering “images” instead of spectra, under the assumption that images showing similar spatial distributions are related to the same chemical species. Such an approach was tested with two Raman maps: one simple “test map” of micro-crystals of four different compounds for a proof of principle and a map of a biological tissue (i.e., cartilage) as an example of chemically complex sample. In both cases, the “image-clustering” approach gave similar results as the traditional HCA, but at lower computational effort. The alternative approach proved to be particularly helpful in cases, as for the cartilage tissue, where concentration gradients of chemical composition are present. Moreover, with this approach, yielded information about correlation between bands in the average spectrum makes band assignment and spectral interpretation easier.

Keywords

Raman mapping Vibrational spectroscopy Biospectroscopy Hierarchical cluster analysis Large data set R-mode 

Notes

Acknowledgements

AB and VS acknowledge partial support from IRCCS Burlo Garofolo, Trieste (Italy) and from FRA 2012 grant from University of Trieste. CB is funded by the German Ministry for Education and Research (BMBF) via the project RamanCTC (13N12685).

Supplementary material

216_2014_8321_MOESM1_ESM.pdf (1.4 mb)
ESM 1 (PDF 1.44 MB)

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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Alois Bonifacio
    • 1
  • Claudia Beleites
    • 2
  • Valter Sergo
    • 1
  1. 1.Centre of Excellence for Nanostructured Materials and Department of Engineering and ArchitectureUniversity of TriesteTriesteItaly
  2. 2.Spectroscopy/ImagingLeibniz Institute of Photonic TechnologyJenaGermany

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