Background levels of hydrogen cyanide in human breath measured by infrared cavity ring down spectroscopy

Abstract

Hydrogen cyanide (HCN) in breath has been suggested as a diagnostic tool for cyanide poisoning and for cyanide-producing bacterial infections. To distinguish elevated levels of breath HCN, baseline data are needed. Background levels of HCN were measured in mixed exhaled air from 40 healthy subjects (26 men, 14 women, age 21-61 years; detection limit: 1.5 ppb; median: 4.4 ppb; range <1.5-14 ppb) by near-infrared cavity ring down spectroscopy (CRDS). No correlation was observed with smoking habits, recent meals or age. However, female subjects had slightly higher breath levels of HCN than male subjects. CRDS has not previously been used for this purpose.

Cyanide in bronchoalveolar lavage is not diagnostic forPseudomonas aeruginosain children with cystic fibrosis

“…The generation of OSCN -, which has antimicrobial properties, is believed to constitute a host defence mechanism [23]. Neutrophil-mediated cyanide generation may therefore explain the results of our study, as well as those of STAMYR et al [24], who detected low cyanide levels in the breath from healthy adults with no lung infections.…”

Background levels and diurnal variations of hydrogen cyanide in breath and emitted from skin

“…In an earlier HCN background study conducted by our group employing CRDS, using the same absorption line as in the current work, we reported a median value of 4.4 ppbv for mixed mouth-exhaled breath samples collected to a 10 liter polyesterlaminated aluminum bag [10]. The line strength available for this transition in the GEISA database at that time (2003 version) was 3.79 ×10 −21 cm molecule −1 at room temperature, a factor of 1.51 smaller than the value in the 2009 version of the same database, given in section 2.3.…”

“…Most prominently, static CRDS measurements were performed in the earlier studies, which led to adsorption losses in the sample cell. In addition, different size and material of the bag, and a different sampling technique (several exhalations were needed to fill the 10 liter bag) played a role in [10], whereas a longer storage time of the breath sample in aluminum-coated bags, as well as unheated RD cell and gas tubings made a difference in [14].…”

“…The concentration of hydrogen cyanide in human breath typically ranges from several parts per billion by volume (ppbv) to tens of ppbv [4,[7][8][9][10][11][12][13][14]. Systemic breath HCN may originate from metabolism, microorganisms, neutrophil-mediated cyanide generation [15] and enzymatic activity [7], or from exogenous sources such as food containing cyanogenic glycosides [16] and exposure to tobacco smoke or combustion gases.…”

“…Apart from an early study using a colorimeter [7], recent state-of-the-art breath HCN measurements have been performed with selected ion flow tube mass spectrometry (SIFT-MS) [4,5,8,9,[11][12][13] and cavity-ring-down spectroscopy (CRDS) [10,14], a laser-based cavity-enhanced absorption technique. Detection of volatile compounds emitted from skin is even more demanding since their concentrations tend to be still lower than in breath, and the collection of skin gas is challenging.…”