Acetone is a good marker of metabolic stress as it is the most volatile and rapidly equilibrated of the ketone bodies
produced by human metabolism. If the body utilizes predominately fat to meet its energy requirements, blood and
breath acetone concentrations will increase. Elevated concentrations of breath acetone can indicate a normal response to
caloric imbalances in the diet, or a diseased state such as untreated diabetes. This paper describes a novel method of
acetone detection that uses a gas-solid chemical reaction of acetone with a hydroxylamine hydrochloride (HA) to
produce an easily detectable chemical species, HCl. Breath samples are passed through a reactor filled with solid HA
and the amount of HCl gas released is measured by sensitive near infrared diode laser spectroscopy. The breath acetone
instrument described is compact, low power and portable.