Document Type

Article

Publication Date

2013

Publication Title

Spectrochimica Acta Part B: Atomic Spectroscopy

Volume

87

First Page

161

Last Page

167

DOI

10.1016/j.sab.2013.05.014

Keywords

Laser-induced breakdown spectroscopy, LIBS; Bacteria, Discriminant function analysis, Partial least squares discriminant analysis, Multivariate analysis

Abstract

Laser-induced breakdown spectroscopy has been used to obtain spectral fingerprints from live bacterial specimens from thirteen distinct taxonomic bacterial classes representative of five bacterial genera. By taking sums, ratios, and complex ratios of measured atomic emission line intensities three unique sets of independent variables (models) were constructed to determine which choice of independent variables provided optimal genuslevel classification of unknown specimens utilizing a discriminant function analysis. A model composed of 80 independent variables constructed from simple and complex ratios of the measured emission line intensities was found to provide the greatest sensitivity and specificity. This model was then used in a partial least squares discriminant analysis to compare the performance of this multivariate technique with a discriminant function analysis. The partial least squares discriminant analysis possessed a higher true positive rate, possessed a higher false positive rate, and was more effective at distinguishing *Revised Manuscript Click here to view linked References 2 between highly similar spectra from closely related bacterial genera. This suggests it may be the preferred multivariate technique in future species-level or strain-level classifications.

Funding Reference Number

RGPIN/418254-2012

Comments

Funding for this project was provided in part by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (RGPIN/418254-2012)

First published at http://dx.doi.org/10.1016/j.sab.2013.05.014

© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

http://creativecommons.org/licenses/by-nc-nd/4.0/

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Physics Commons

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