Secondary electrospray ionization coupled to high-resolution mass spectrometry reveals tryptophan pathway metabolites in exhaled human breath.

ABSTRACT

Many studies and personalized medicine in general require frequent measurements and/or rapid results of biomarker levels. Here we show that 20 low volatility metabolites of the tryptophan pathway can be detected in exhaled human breath. This real-time and non-invasive method offers an attractive alternative to blood analysis.