Title: | A workflow for the metabolomic/metabonomic investigation of exhaled breath using thermal desorption GC-MS |
Author(s): | Guallar-Hoyas C; Turner MA; Blackburn GJ; Wilson ID; Thomas CL; |
Address: | "Centre for Analytical Sciences, Department of Chemistry, Loughborough University, Leicestershire, LE11 3TU, UK" |
ISSN/ISBN: | 1757-6199 (Electronic) 1757-6180 (Linking) |
Abstract: | "BACKGROUND: Confounding factors in the analysis of human breath by thermal desorption GC-MS are reviewed, with special emphasis on the high water levels encountered in human breath samples. RESULTS: Multilinear regression optimization of breath sampling factors, along with the selection of ubiquitous sample components used as retention-time standards, enabled data registration based on retention indexing and mass spectral alignment. This was done on a component-by-component basis. The methodology developed reconciled participant safety, artefacts from accelerated hydrolysis of the stationary phase and the destructive nature of thermal desorption. Furthermore, using ubiquitous methylated cyclic-siloxanes in the thermal desorption-GC-MS chromatograms enabled secondary retention indexing for each chromatogram. This methodology enables the creation of a 'breath matrix' that is based on a combination of retention indexing and the mass spectral registration of isolated peaks. CONCLUSION: This approach facilitated more efficient data modeling and a case study from a 22-participant (10 male, 12 female) stress-intervention experiment. Principal component analysis of data registered by retention indexing did not classify successfully stressed from unstressed states. By contrast, adoption of a breath matrix approach enabled 95% separation" |
Keywords: | Case-Control Studies *Exhalation Female Gas Chromatography-Mass Spectrometry/methods Humans Male Metabolomics/*methods Principal Component Analysis Regression Analysis Research Design *Respiration Volatile Organic Compounds/*analysis/chemistry Young Adult; |
Notes: | "MedlineGuallar-Hoyas, Cristina Turner, Matthew A Blackburn, Gavin J Wilson, Ian D Thomas, C L Paul eng Biotechnology and Biological Sciences Research Council/United Kingdom Research Support, Non-U.S. Gov't England 2012/10/11 Bioanalysis. 2012 Sep; 4(18):2227-37. doi: 10.4155/bio.12.193" |