title: Background levels and diurnal variations of hydrogen cyanide in breath and emitted from skin.
abstract: The hydrogen cyanide (HCN) concentration in exhaled human breath and skin gas samples collected with different sampling techniques was measured using near-infrared cavity ring-down spectroscopy. The median baseline HCN concentrations in samples provided by 19 healthy volunteers 2-4 h after the last meal depended on the employed sampling technique: 6.5 parts per billion by volume (ppbv) in mixed (dead space and end-tidal) mouth-exhaled breath collected to a gas sampling bag, 3.9 ppbv in end-tidal mouth-exhaled breath, 1.3 ppbv in end-tidal nose-exhaled breath, 1.0 ppbv in unwashed skin and 0.6 ppbv in washed skin samples. Diurnal measurements showed that elevated HCN levels are to be expected in mouth-exhaled breath samples after food and drink intake, which suggests HCN generation in the oral cavity. The HCN concentrations in end-tidal nose-exhaled breath and skin gas samples were correlated, and it is concluded that these concentrations best reflect systemic HCN levels.
authors.affiliation: Laboratory of Physical Chemistry, Department of Chemistry, PO Box 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki, Finland.
authors.forename: F M
authors.initials: FM
authors.lastname: Schmidt
authors.forename: M
authors.initials: M
authors.lastname: Metsälä
authors.forename: O
authors.initials: O
authors.lastname: Vaittinen
authors.forename: L
authors.initials: L
authors.lastname: Halonen
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002940:Circadian Rhythm; D045853:Exhalation; D005260:Female; D006801:Humans; D006856:Hydrogen Cyanide / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000737:chemistry*; D055815:Young Adult
chemical_list: D006856:Hydrogen Cyanide