On-line Breath Metabolomics in Respiratory Diseases using Secondary Electrospray Ionization-Mass Spectrometry.

Every second we are exhaling hundreds of endogenous and exogenous compounds that originate from blood and lung tissue. Obtaining metabolic information via exhaled breath analysis has been an emerging topic since the 1970s. Secondary electrospray ionization-mass spectrometry is a relatively new technique to detect these metabolites on-line in a highly sensitive and specific fashion. Using this technique, several respiratory diseases, including chronic obstructive pulmonary disease, obstructive sleep apnea, idiopathic pulmonary fibrosis, asthma, and lung cancer have been investigated over the past years. Several new potential biomarkers for these diseases were identified and new metabolic insights into their pathophysiology could be obtained.