EXPRESS: High-Sensitivity Detection of Acetone in Human Breath Using Near-Infrared Continuous Wave Cavity Ring-Down Spectroscopy

This study utilizes the capabilities of continuous wave cavity ring-down spectroscopy (CW-CRDS) at a wavelength around 1672 nm for detecting acetone and methane in exhaled human breath. We employed a commercial distributed feedback diode laser (DFB), which delivered approximately 4 mW of power across a tuning range of 3.5 nm to measure acetone and methane concentrations in exhaled human breath. The detection limit as low as approximately 10.5 parts per billion (ppb) was demonstrated. Samples were collected from two distinct population locations: 23 individuals sourced from Doha, Qatar, and 19 volunteers from College Station, Texas. The content of multiple gas mixture components was determined. The developed method for retroactive determination of the laser tuning eliminated the need for on-line wavelength determination. Simultaneous measurements of acetone and methane in exhaled breath can assist in diagnostics and monitoring of diabetes and metabolic profile of individuals using this noninvasive technique.