Applications of Machine Olfaction - The Electronic Nose Artificial Olfaction Technology - page 217

Fig. 8.1 Breath sampling
system [ 52 ]

Table 8.6 Physiological origin of some breath molecules
Breath molecules Physiological origins

Acetaldehyde Ethanol metabolism

Acetone Decarboxylation of acetoacetate

Ammonia Protein metabolism

Carbon disulfide Gut bacteria

Carbon monoxide Production catalyzed by heme oxygenase

Carbon sulfide Gut bacteria

Ethane Lipid peroxidation

Ethanol Gut bacteria

Ethylene Lipid peroxidation

Hydrocarbons Lipid peroxidation/metabolism

Hydrogen Gut bacteria

Isoprene Cholesterol biosynthesis

Methane Gut bacteria

Methanethiol Methionine metabolism

Methanol Metabolism of fruit

methylamine Protein metabolism

Nitric oxide Production catalyzed by nitric oxide synthase

Pentane Lipid peroxidation

8.1.10 Case Study 1: Practical Approach to Detect Asthma
in Human Breath

8.1.10.1 The Problem

Measurement of volatile compounds and odors in breath using E-noses is the
low-cost, real-time, qualitative, and portable technique to carry out reliable,
reproducible, and objective measurement. To achieve a reliable, subjective, and
analytically acceptable system it is required the awareness of the difference between