A Comparison between THz Spectroscopy and GC-MS by Detection of Isopropanol in Human Breath

We present a comparison between THz spectroscopy and gas chromatography-mass spectroscopy (GC-MS), which is considered the gold-standard for sensitive breath detection. For this purpose, we analyzed human breath samples with both methods and discuss key figures as well as advantages and disadvantages for this application. As an example, the detection of isopropanol is presented which was exhaled after hand disinfection of a volunteer. THz spectroscopy provides results consistent with GC-MS and even distinguishes conformers of isopropanol. The sensitivity of the THz spectrometer for isopropanol is roughly 500 times smaller in this case, but can be improved depending on the species and measurement parameters.