Trends in Direct Breath Analysis by Secondary Electrospray Ionization Mass Spectrometry for Clinical Applications

Abstract

Exhaled breath reveals insights about the metabolic state of the human body through the endo- and exogenous compounds it contains. The extent of detectable compounds, however, was revolutionized by the application of mass spectrometry. More specifically, secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS) enables the detection of a broad range of breath-derived compounds simultaneously and with high sensitivity. Together with its rapid and non-invasive nature, direct breath analysis by SESI-HRMS gained particular interest for clinical applications. Over the past years, various clinical trials successfully demonstrated the technology’s capability for biomarker discovery in exhaled breath in adults and more recently in children. Current challenges lie within the potential translation of SESI-HRMS into clinical settings and the associated requirements, such as unambiguous biomarker identification and validation, which were objectives of more recent studies.