Scientists from the University of Oxford and Oxford Medical Diagnostics, an Oxfordshire, UK firm, are reporting in journal Analytical Chemistry on a new technique for measuring acetone in exhaled breath. Having a way of accurately measuring exhaled acetone can help diagnose diabetes, and even screen for it, without taking a blood sample.
Breath has a lot of biomarkers, including acetone, that can point to the presence of disease. Detecting these is difficult because different compounds, including water, CO2, and CH4, muddy up the results. The new technology overcomes this by using an adsorbent polymer that grabs onto acetone and releases it into a special cavity. Within the cavity is a laser sensor that can accurately measure acetone’s concentration, quickly producing results.
The researchers compared the new sensor against values measured by a mass spectrometer, a gold standard for breath compound measurement, with great results. These even were accurate under different conditions, including following physical exercise.
From the study abstract:
The device features a 7 cm long high finesse optical cavity as an optical sensor that is coupled to a miniature adsorption preconcentrator containing 0.5 g of polymer material. Acetone is trapped out of breath and released into the optical cavity where it is probed by a near-infrared diode laser operating at ∼1670 nm. With an optical cavity mirror reflectivity of 99.994%, a limit of detection of 159 ppbv (1σ) is demonstrated on samples from breath bags.
Study in journal Analytical Chemistry: Portable Device for Measuring Breath Acetone Based on Sample Preconcentration and Cavity Enhanced Spectroscopy…