Articles
William J. Foley
Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra 0200, Australia
A.N. Davies,a H.M. Heiseb and D.F. Ihrigc
aProfessor, SERC, University of Glamorgan, UK, Director, ALIS Ltd, and ALIS GmbH—Analytical Laboratory Informatics Solutions
bISAS—Institute for Analytical Sciences at Dortmund University of Technology, Bunsen-Kirchhoff-Str. 11, D-44139 Dortmund, Germany
cUniversity of Applied Sciences of South-Westphalia, Frauenstuhlweg 31, D-58644 Iserlohn, Germany
Following on from our previous foray into the UV-visible area of the spectrum, in this article we discuss its nearest neighbour in the spectral scale, namely near infrared (NIR) spectrometry. The NIR spectral region lies between 780 nm and 2500 nm (4000 cm–1 to 12,800 cm–1) bridging the more well-known and analytically used regions of the UV-visible (190–780 nm) and the infrared (4000–600 cm–1).
Tom Scherzer, Gabriele Mirschel and Katja Heymann
Leibniz Institute of Surface Modification (IOM), Permoserstr. 15, D-04318 Leipzig, Germany. E-mail: [email protected]
A.M.C. Daviesa and Tom Fearnb
aNorwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK. E-mail: [email protected]
bDepartment of Statistical Science, University College London, Gower Street, London WC1E 6BT, UK. E-mail: [email protected]
A.M.C. Davies and Tom Fearn
Norwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK. E-mail: [email protected]
Department of Statistical Science, University College London, Gower Street, London WC1E 6BT, UK. E-mail: [email protected]
The starting point for this column is the last one from last year! In that column TD began what was intended to be a two-part story but has, with this column, become a story in four parts. There were required topics we had not covered and we need to begin this column by completing the discussion of removing multiplicative effects by describing what the two most popular methods do to NIR spectra.
The last TD column showed the effect of calculating second derivatives on a set of 100 spectra, which will be the starting point for this column.
This column is about the most basic of pre-treatments, which has been used in spectroscopy well before the word "Chemometrics" was invented.
This article focusses on the application of near infrared (NIR) spectroscopy as a potential substitute to the sensory evaluation of tea quality.
Erik Skibsted
Novo Nordisk, CMC Supply, Analytical Development, Denmark. E-mail: [email protected]
Gerard Downey,a* J. Daniel Kellya and Cristina Petisco Rodriguezb
aTeagasc, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland. E-mail: [email protected]
b Instituto de Recursos Naturales y Agrobiología, CSIC, Apdo 257, 37071 Salamanca, Spain
S. Benali,a D. Bertrand,b J. Dupuyc and G. Lachenald
aUniversité de Mons Hainaut, Matériaux Polymères et Composites, Place du Parc, 20 ,7000 Mons, Belgium
bENITIAA-INRA, Unité de Sensométrie et Chimiométrie, BP 82225, 44322 Nantes Cedex 03, France. E-mail: [email protected]
A.M.C. Davies
Norwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK
Introduction
In my last column I began a revision of basic chemometrics.1 In this column I will discuss some interpretation of the results produced by principal component analysis (PCA) as part two of this revision programme.
Gerhard Litscher
Biomedical Engineering and Research in Anesthesia and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 36, A-8036 Graz, Austria. E-mail: [email protected]; http://litscher.at; http://litscher.info
PCA is a mathematical method of reorganising information in a data set of samples. It can be used when the set contains information from only a few variables but it becomes more useful when there are large numbers of variables, as in spectroscopic data.
A.M.C. Davies
Norwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK
Richard A. Crocombe
Axsun Technologies, Inc., 1 Fortune Drive, Billerica, MA 01821, USA
A.M.C. Davies
Norwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK
A.M.C.Davies,a and Tom Fearn,b
aNorwich Near Infrared Consultancy, 75 Intwood Road, Cringleford, Norwich NR4 6AA,UK
bDepartment of Statistical Science, University College London, Gower Street, London
