title: An exploratory comparative study of volatile compounds in exhaled breath and emitted by skin using selected ion flow tube mass spectrometry.
abstract: Selected ion flow tube mass spectrometry (SIFT-MS) has been used to carry out a pilot parallel study on five volunteers to determine changes occurring in several trace compounds present in exhaled breath and emitted from skin into a collection bag surrounding part of the arm, before and after ingesting 75 g of glucose in the fasting state. SIFT-MS enabled real-time quantification of ammonia, methanol, ethanol, propanol, formaldehyde, acetaldehyde, isoprene and acetone. Following glucose ingestion, blood glucose and trace compound levels were measured every 30 min for 2 h. All the above compounds, except formaldehyde, were detected at the expected levels in exhaled breath of all volunteers; all the above compounds, except isoprene, were detected in the collection bag. Ammonia, methanol and ethanol were present at lower levels in the bag than in the breath. The aldehydes were present at higher levels in the bag than in breath. The blood glucose increased to a peak about 1 h post-ingestion, but this change was not obviously correlated with temporal changes in any of the compounds in breath or emitted by skin, except for acetone. The decrease in breath acetone was closely mirrored by skin-emitted acetone in three volunteers. Breath and skin acetone also clearly change with blood glucose and further work may ultimately enable inferences to be drawn of the blood glucose concentration from skin or breath measurements in type 1 diabetes.
authors.affiliation: Cranfield Health, Cranfield University, Silsoe, Bedford MK45 4DT, UK. c.turner@cranfield.ac.uk
authors.forename: Claire
authors.initials: C
authors.lastname: Turner
authors.forename: Bhavin
authors.initials: B
authors.lastname: Parekh
authors.forename: Christopher
authors.initials: C
authors.lastname: Walton
authors.forename: Patrik
authors.initials: P
authors.lastname: Spanel
authors.forename: David
authors.initials: D
authors.lastname: Smith
authors.forename: Mark
authors.initials: M
authors.lastname: Evans
mesh_terms: D016477:Artifacts; D001774:Blood Chemical Analysis / Q000379:methods*; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004176:Dipyridamole / Q000097:blood*; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D005740:Gases / Q000097:blood; D006801:Humans; D009930:Organic Chemicals / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D014835:Volatilization
chemical_list: D005740:Gases; D009930:Organic Chemicals; D004176:Dipyridamole