Gas Chromatography-Mass Spectrometry Analysis of Human Exhaled Volatile Organic Compounds via Wearable Facemask Microextraction Sampling

Human exhaled breath contains a large number of volatile metabolites relating to human behavior and health states. In this study, solid phase microextraction ( SPME) fibers were directly inserted into a facemask ( SPME-in-facemask) to form a new facemask microextraction device for extracting human exhaled volatile organic compounds ( VOCs). After sampling, SPME fibers were then coupled with different gas chromatography-mass spectrometers ( GC-MS) for further identification of extracted VOCs, including conventional GC-MS, portable GC-MS and comprehensive two-dimensional GC-MS. Different SPME fibers and sampling time were investigated and compared. By comparing the background signals of face mask human exhaled VOCs, the effects of food intake and oral care on the compositions and changes of human exhaled VOCs were explored. The detectability and persistence of exhaled exogenous VOCs were investigated. The results showed that the facemask microextraction sampling coupled with GC-MS could be an efficient analytical tool for detecting a large amount of exhaled endogenous and exogenous VOCs. With the unique features of the facemask microextraction device, including safety, simplicity, convenient sampling, and strong adaptability to couple with different GC-MS methods in which portable GC-MS could provide a fast screening within minutes, while GC x GC-MS could give a comprehensive analysis for biomarker discovery. This work presented a novel promising strategy for investigating human health and oral diseases.