Via the New York Times, this news:
Coronavirus infections might soon be flagged with a puff of exhaled breath, after the Food and Drug Administration authorized the first breath-based Covid-19 test in the United States on Thursday.
The emergency use authorization of the InspectIR Covid-19 Breathalyzer is a meaningful milestone in the yearslong quest to develop more breath-based diagnostics, as well as innovative new tests for Covid, experts said. And it is likely to be the first of many similar breath-based Covid tests, experts said.
....To use the device, patients blow into a cardboard straw attached to a chemical analyzer. “It’s a chemistry lab in a box,” Mr. Redmond said. The machine then analyzes the levels of five volatile organic compounds, or V.O.C.s, that together make up a “breath print” of Covid, Mr. Redmond said. (InspectIR said it could not disclose what the five compounds are.) Results are delivered within three minutes, the company said...
The FDA press release says it's a GC/MS. Sure would be nice to know what the compounds are (here's another paper where one of the compounds that is detected in COVID infections was iodobenzene, of all things...).