| Title: | Effects of modular ion-funnel technology onto analysis of breath VOCs by means of real-time mass spectrometry |
| Author(s): | Pugliese G; Piel F; Trefz P; Sulzer P; Schubert JK; Miekisch W; |
| Address: | "Department of Anaesthesia and Intensive Care, Rostock University Medical Center, Schillingallee 35, 18057, Rostock, Germany. IONICON Analytik GmbH, Eduard-Bodem-Gasse 3, 6020, Innsbruck, Austria. Institute for Ion Physics and Applied Physics, University of Innsbruck, Technikerstr. 25, 6020, Innsbruck, Austria. Department of Chemistry, University of Oslo, Sem Saelands vei 26, 0371, Oslo, Norway. Department of Anaesthesia and Intensive Care, Rostock University Medical Center, Schillingallee 35, 18057, Rostock, Germany. wolfram.miekisch@uni-rostock.de" |
| DOI: | 10.1007/s00216-020-02846-8 |
| ISSN/ISBN: | 1618-2650 (Electronic) 1618-2642 (Print) 1618-2642 (Linking) |
| Abstract: | "Proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) is a powerful tool for real-time monitoring of trace concentrations of volatile organic compounds (VOCs). The sensitivity of PTR-ToF-MS also depends on the ability to effectively focus and transmit ions from the relatively high-pressure drift tube (DT) to the low-pressure mass analyzer. In the present study, a modular ion-funnel (IF) is placed adjacent to the DT of a PTR-ToF-MS instrument to improve the ion-focusing. IF consists of a series of electrodes with gradually decreasing orifice diameters. Radio frequency (RF) voltage and direct current (DC) electric field are then applied to the electrodes to get the ions focused. We investigated the effect of the RF voltage and DC field on the sensitivity of a pattern of VOCs including hydrocarbons, alcohols, aldehydes, ketones, and aromatic compounds. In a proof-of-concept study, the instrument operating both as normal DT (DC-mode) and at optimal IF conditions (RF-mode) was applied for the breath analysis of 21 healthy human subjects. For the range of investigated VOCs, an improvement of one order of magnitude in sensitivity was observed in RF-mode compared with DC-mode. Limits of detection could be improved by a factor of 2-4 in RF-mode compared with DC-mode. Operating the instrument in RF-mode allowed the detection of more compounds in the exhaled air compared with DC-mode. Incorporation of the IF considerably improved the performance of PTR-ToF-MS allowing the real-time monitoring of a larger number of potential breath biomarkers. Graphical abstract" |
| Keywords: | Adult *Breath Tests Female Humans Ions Limit of Detection Male Mass Spectrometry/*methods Middle Aged Proof of Concept Study Volatile Organic Compounds/*analysis Young Adult Breath analysis Ion-funnel PTR-ToF-MS Real-time mass spectrometry VOCs; |
| Notes: | "MedlinePugliese, Giovanni Piel, Felix Trefz, Phillip Sulzer, Philipp Schubert, Jochen K Miekisch, Wolfram eng IMPACT/674911/H2020 Marie Sklodowska-Curie Actions/ Germany 2020/08/15 Anal Bioanal Chem. 2020 Oct; 412(26):7131-7140. doi: 10.1007/s00216-020-02846-8. Epub 2020 Aug 13" |
