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The use of GC×GC/TOF MS with multivariate analysis for the characterization of foodborne pathogen bacteria profiles
Author(s) -
Gardner J. Yvette,
Brillhart Darcy E.,
Benjamin Melissa M.,
Dixon Lurlene G.,
Mitchell LaTonya M.,
Dimandja JeanMarie D.
Publication year - 2011
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201000612
Subject(s) - chromatography , chemistry , gas chromatography , kovats retention index , gas chromatography–mass spectrometry , mass spectrometry , gram , bacteria , biology , genetics
The cellular fatty acid profiles of eight strains of Bacillus , Staphylococcus , and Enterobacteriacae ( Escherichia coli and Salmonella ) were analyzed by comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry. A novel template method was developed to standardize the raw two‐dimensional gas chromatography retention data through the use of a chemical indexing mixture. Analyte retention coordinates were normalized in the primary dimension with respect to a series of n ‐alkanes (Kovats index) and in the secondary dimension with respect to a series of aromatic hydrocarbons (Lee index). Fatty acid profiles extracted from the templates were compared by multidimensional scaling and principal component analysis. Differences in the profiles of Gram‐positive and Gram‐negative bacteria were observed, and a series of heterogeneous mixtures comprising different fractions (containing one Gram‐positive and one Gram‐negative bacteria strain) were also distinguished from their homogeneous constituents.