A selected ion flow tube mass spectrometry study of ammonia in mouth- and nose-exhaled breath and in the oral cavity.
A study has been carried out, involving three healthy volunteers, of the ammonia levels in breath exhaled via the mouth and via the nose and in the static oral cavity using on-line, selected ion flow tube mass spectrometry (SIFT-MS), obviating the problems associated with sample collection of ammonia. The unequivocal conclusion drawn is that the ammonia appearing in the mouth-exhaled breath of the three volunteers is largely generated in the oral cavity and that the ammonia originating at the alveolar interface in the lungs is typically at levels less than about 100 parts-per-billion, which is a small fraction of the total breath ammonia. This leads to the recommendation that exhaled breath analyses should focus on nose-exhaled breath if the objective is to use breath analysis to investigate systemic, metabolic disease.
Smith
David
D
Institute for Science and Technology in Medicine, School of Medicine, Keele University, Thornburrow Drive, Hartshill, Stoke-on-Trent ST4 7QB, UK. d.smith@bemp.keele.ac.uk
Wang
Tianshu
T
Pysanenko
Andriy
A
Spanel
Patrik
P
D000641:Ammonia / Q000032:analysis*; D001944:Breath Tests / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D045853:Exhalation / Q000502:physiology*; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D009055:Mouth / Q000378:metabolism*; D009297:Nasal Mucosa / Q000378:metabolism*; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods
D000641:Ammonia