Complex numbers in chemometrics - Examples from multivariate impedance measurements on lipid monolayers

Abstract

Electrical impedance gives multivariate complex number data as results. Two examples of multivariate electrical impedance data measured on lipid monolayers in different solutions give rise to matrices (16 x 50 and 38 x 50) of complex numbers. Multivariate data analysis by principal component analysis (PCA) or singular value decomposition (SVD) can be used for complex data and the necessary equations are given. The scores and loadings obtained are vectors of complex numbers. It is shown that the complex number PCA and SVD are better at concentrating information in a few components than the naive juxtaposition method and that Argand diagrams can replace score and loading plots. Different concentrations of Magainin and Gramicidin A give different responses and also the role of the electrolyte medium can be studied. An interaction of Gramicidin A in the solution with the monolayer over time can be observed. (c) 2007 Published by Elsevier B.V

Published in

Analytica Chimica Acta
2007, Volume: 595, number: 1-2, pages: 152-159
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Geladi, Paul

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    

Publication identifier

DOI: https://doi.org/10.1016/j.aca.2007.01.037

Permanent link to this page (URI)

https://res.slu.se/id/publ/17284