title: Demonstration of a mid-infrared cavity enhanced absorption spectrometer for breath acetone detection.
abstract: A high-resolution absorption spectrum of gaseous acetone near 8.2 μm has been taken using both Fourier transform and quantum cascade laser (QCL)-based infrared spectrometers. Absolute absorption cross sections within the 1215-1222 cm(-1) range have been determined, and the spectral window around 1216.5 cm(-1) (σ = 3.4 × 10(-19) cm(2) molecule(-1)) has been chosen for monitoring trace acetone in exhaled breath. Acetone at sub parts-per-million (ppm) levels has been measured in a breath sample with a precision of 0.17 ppm (1σ) by utilizing a cavity enhanced absorption spectrometer constructed from the QCL source and a linear, low-volume, optical cavity. The use of a water vapor trap ensured the accuracy of the results, which have been corroborated by mass spectrometric measurements.
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom.
authors.forename: Luca
authors.initials: L
authors.lastname: Ciaffoni
authors.forename: Gus
authors.initials: G
authors.lastname: Hancock
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Harrison
authors.forename: Jean-Pierre H
authors.initials: JP
authors.lastname: van Helden
authors.forename: Cathryn E
authors.initials: CE
authors.lastname: Langley
authors.forename: Robert
authors.initials: R
authors.lastname: Peverall
authors.forename: Grant A D
authors.initials: GA
authors.lastname: Ritchie
authors.forename: Simon
authors.initials: S
authors.lastname: Wood
mesh_terms: D000096:Acetone / Q000032:analysis*; D001944:Breath Tests; D006801:Humans; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation
chemical_list: D000096:Acetone