Analyses of volatile metabolites in breath by a combination of thermal desorption, TD, with selected ion flow tube mass spectrometry, SIFT-MS

摘要

Development of sample collection method for off-line GC-MS and SIFT-MS analyses will be presented that has been carried out in order to study breath biomarkers of bacterial infections in patients with cystic fibrosis by quantitative analyses of volatiles in exhaled breath and headspace of sputum and bacterial cultures. Research of non-invasive methods for diagnosis and monitoring of bacterial infection in cystic fibrosis is currently a topic of great interest. Hydrogen cyanide has been identified as a breath biomarker of Pseudomonas aeruginosa (PA) infection. However, some strains of PA do not produce HCN. Thus other volatile breath biomarkers are needed order to improve the sensitivity and specificity. We propose to study trace amounts of volatile compounds in breath of CF patients using selected ion flow tube mass spectrometry (SIFT-MS) and gas chromatography mass spectrometry (GC-MS). SIFT-MS quantification of trace gases at low concentrations (<10 parts-per-billion by volume, ppbv) is achieved by reactions of ions H3O+, NO+ and O2+ with the molecules of analyte. Sample collection using thermal desorption tubes is used for off-line analyses and for discovery of breath biomarkers of bacterial infections in patients with cystic fibrosis by quantitative analyses of volatiles in exhaled breath and headspace of sputum and bacterial cultures.