Standardization of the collection of exhaled breath condensate and exhaled breath aerosol using a feedback regulated sampling device

摘要

Exhaled breath condensate (EBC) and associated exhaledbreathaerosols (EBA) are valuable non-invasive biological media used for the quantification of biomarkers. EBC contains exhaled water vapor, soluble gas-phase (polar) organic compounds, ionic species, plus other species including semi- and non-volatile organic compounds, proteins, cell fragments,DNA, dissolved inorganic compounds, ions, andmicrobiota (bacteria and viruses) dissolved in the co-collected EBA. EBC is collected from subjects who breathe ‘normally’ through a chilled tube assembly for approximately 10min and is then harvested into small vials for analysis. Aerosol filterswithout the chilled tube assembly are also used to separately collect EBA. Unlike typical gas-phase breath samples used for environmental and clinical applications, the constituents of EBC and EBA are not easily characterized by total volume or carbon dioxide (CO_2) concentration, because the gas-phase is vented. Furthermore, EBC and associated EBA are greatly affected by breathing protocol, more specifically, depth of inhalation and expelled breath velocity.We have tested a new instrument developed by LoccioniGruppaHumancare (Ancona, Italy) for implementation of EBC collection from human subjects to assess EBC collection parameters. The instrument is the first EBC collection device that provides instantaneous visual feedback tothe subjects tocontrol breathing patterns. In this report we describe the operation of the instrument, and present an overviewof performance and analytical applications.