“…Recently, different methods have been used for analysis of exhaled breath or exhaled breath condensate to detect COVID-19, such as gas chromatography-mass spectrometry (GC-MS) 9,10 , proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) [11][12][13] , Fourier transform infrared spectroscopy (FTIR) 14 , gas chromatography-ion mobility spectrometry (GC-IMS) 15,16 , sensors and electronic nose 17,18 , and others 19,20 . In April 2022, the US Food and Drug Administration approved the first COVID-19 screening test by GC-MS analysis of breath samples under emergency use authorization (EUA) 21 .…”