Express analysis of acetone in exhaled air for diagnosing diabetes melli-tus

Abstract

Exhaled air analysis is an actively developing area of medical non-invasive diagnostics, as it does not involve invasive interventions and can be performed repeatedly. It is known that acetone in exhaled air correlates with blood glucose and is a biomarker of diabetes. The use of analytical systems to analyse acetone in exhaled air in medical institutions will allow for the timely diagnosis of pathological changes in blood glucose levels, the early diagnosis of diabetes, and the monitoring of the effectiveness of treatments. In this study, we described the express analysis of acetone in exhaled air using a mobile diagnostic complex based on microfluidic systems including a PIA gas microchromatograph with a thermochemical detector, a planar chromatographic column, a thermostatically controlled system for the sampling and selective capture of interfering components, operated by electric microvalves, and an automatic dosing system with adjustable blowdown from 0.1 to 5 sec and specialised software. We proposed using a diagnostically significant range of concentrations: from 0.5 ppm to 20 ppm of acetone in exhaled air in the diagnosis of diabetes. The total analysis time is 3 min, retention time for acetone is 60 sec. Testing of the complex confirmed that it allows for the direct determination of acetone in exhaled air. The use of the capture and drying system prevents the loss of the target substance and ensures good convergence of the results. The deviation from the reference value does not exceed 10%. Field testing confirmed the data obtained on model mixtures. The developed mobile diagnostic complex with automatic programmed dosing and the technique for the quantitative determination of acetone in exhaled air (0.5-20 ppm) can be recommended for use in clinical studies in medical institutions.