Ronja Weber, Bettina Streckenbach, Lara Welti, Demet Inci, Malcolm Kohler, Nathan Perkins, Renato Zenobi, Srdjan Micic , and Alexander Moeller.

There is a need to improve the diagnosis and management of pediatric asthma. Breath analysis aims to address this by non-invasively assessing altered metabolism and disease-associated processes.

Patrik Španěl, Kseniya Dryahina, Maroua Omezzine Gnioua, David Smith

The detection sensitivity of secondary electrospray ionisation mass spectrometry (SESI-MS) is much lower for saturated aldehydes than for unsaturated aldehydes. This needs to be understood in terms of gas phase ion-molecule reaction kinetics and energetics to make SESI-MS analytically more quantitative.

Kim Arnold, Philippe Dehio, Jonas Lötscher, Kapil Dev Singh, Diego García-Gómez, Christoph Hess, Pablo Sinues, and Maria L. Balmer

Dendritic cells (DCs) actively sample and present antigen to cells of the adaptive immune system and are thus vital for successful immune control and memory formation. Immune cell metabolism and function are tightly interlinked, and a better understanding of this interaction offers potential to develop immunomodulatory strategies. However, current approaches for assessing the immune cell metabolome are often limited by endpoint measurements, may involve laborious sample preparation, and may lack unbiased, temporal resolution of the metabolome. In this study, we present a novel setup coupled to a secondary electrospray ionization-high resolution mass spectrometric (SESI-HRMS) platform allowing headspace analysis of immature andactivated DCs in real-time with minimal sample preparation and intervention, with high technical reproducibility and potential for automation.

Bettina Streckenbach, Justinas Sakas, Nathan Perkins, Malcolm Kohler, Alexander Moeller and Renato Zenobi.

Applications for direct breath analysis by mass spectrometry (MS) are rapidly expanding. One of the more recent mass spectrometry-based approaches is secondary electrospray ionization coupled to high-resolution mass spectrometry (SESI-HRMS). Despite increasing usage, the SESI methodology still lacks standardization procedures for quality control and absolute quantification.

Cedric Wüthrich, Zhiyuan Fan, Guy Vergères, Fabian Wahl, Renato Zenobi and Stamatios Giannoukos.s

Quantification of metabolites present within exhaled breath is a major challenge for on-line breath analysis. It is also important for gauging the analytical performance, accuracy, reproducibility, reliability, and stability of the measuring technology. Short-chain fatty acids (SCFAs) are of high interest for nutrition and health.

Amanda Gisler, Kapil Dev Singh, Jiafa Zeng, Martin Osswald, Mo Awchi, Fabienne Decrue, Felix Schmidt, Noriane A. Sievi, Xing Chen, Jakob Usemann, Urs Frey, Malcolm Kohler, Xue Li, Pablo Sinues

Exhaled breath contains valuable information at the molecular level and offers promising potential for precision medicine. However, few breath tests transition to routine clinical practice, partly because of the missing validation in multicenter trials. Therefore, we developed and applied an interoperability framework for standardized multicenter data acquisition and processing for breath analysis with secondary electrospray ionization-high resolution mass spectrometry.

Ronja Weber, Jérôme Kaeslin, Sophia Moeller, Nathan Perkins, Srdjan Micic, and Alexander Moeller.

Environmental volatile organic compounds (VOCs) from the ambient air potentially influence on-line breath analysis measurements by secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS). The aim of this study was to investigate how inhaling through a VOC filter affects the detected breath profiles and whether it is feasible to integrate such filters into routine measurements..

T. Zivkovic Semren*, S. Majeed, M. Fatarova, C. Laszlo, C. Pak, S. Steiner, G. Vidal, A. Kuczaj, A. Mazurov, M. C. Peitsch, N. V. Ivanov, J. Hoeng, P. A. Guy

Inhalation as a route for administering drugs and dietary supplements has garnered significant attention over the last decade. We performed real-time analysis of aerosols using secondary electrospray ionization (SESI) technology interfaced with high-resolution mass spectrometry (HRMS)

R Weber, B Streckenbach, J Kaeslin, L Welti, D Inci, N Perkins, R Zenobi, S Micic, A Möller.
We hypothesized that the breath of children with allergic asthma contains a unique signature of disease specific metabolites. Using secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS), we aimed to identify relevant VOCs to assess underlying interconnections between biomarkers belonging to common metabolic pathways in the pathophysiology of asthma.

Xin Xu, Hongwei Pang, Chao Liu, Kangyi Wang, Gwendal Loisel, Lei Li, Sasho Gligorovski, Xue Li

Human presence can affect indoor air quality because of secondary organic compounds formed upon reactions between gaseous oxidant species, e.g., ozone (O₃), hydroxyl radicals (OH), and chemical compounds from skin, exhaled breath, hair and clothes. We assess the gas-phase product compounds generated by reactions of gaseous O₃ with volatile organic compounds (VOCs) from exhaled human breath…

Felix Schmidt, Nora Nowak, Patrick Baumgartner, Thomas Gaisl, Stefan Malesevic, Bettina Streckenbach, Noriane A. Sievi, Esther I. Schwarz, Renato Zenobi, Steven A. Brown, and Malcolm Kohler.

The direct pathophysiological effects of obstructive sleep apnea (OSA) have been well described. However, the systemic and metabolic consequences of OSA are less well understood.

Huifan Deng, Xin Xu, Kangyi Wang, Jinli Xu, Gwendal Loisel, Yiqun Wang, Hongwei Pang, Pan Li, Zebin Mai, Shichao Yan, Xue Li,Sasho Gligorovski

The primarily emitted compounds by human presence, e.g., skin and volatile organic compounds (VOCs) in breath, can react with typical indoor air oxidants, ozone (O₃), and hydroxyl radicals (OH), leading to secondary organic compounds…

A. Gómez-Mejia, K. Arnold, J. Bär, K. Dev Singh, T. C. Scheier, S. D. Brugger, A. S. Zinkernagel, P. Sinues

Early detection of pathogenic bacteria is needed for rapid diagnostics allowing adequate and timely treatment of infections.

Ronja Weber, Nathan Perkins, Tobias Bruderer, Srdjan Micic and Alexander Moeller.

The early detection of inflammation and infection is important to prevent irreversible lung damage in cystic fibrosis. Novel and non-invasive monitoring tools would be of high benefit for the quality of life of patients.

F. Schmidt ; M. Osswald ; R. Zenobi ; M. Kohler

Monitoring of drug pharmacokinetics is used in personalized therapy, therapeutic drug monitoring (TDM), toxicology assessments, doping controls and clinical drug development. Drugs are predominantly measured in plasma, serum or urine. Monitoring of volatile organic compounds (VOCs) in breath has so far not received much attention, but nevertheless it has many advantages over conventional approaches

Huifan Deng, Pascale S. J. Lakey, Yiqun Wang, Pan Li, Jinli Xu, Hongwei Pang, Jiangping Liu, Xin Xu, Xue Li, Xinming Wang, Yuzhong Zhang, Manabu Shiraiwa, and Sasho Gligorovski

The reactions of sulfur dioxide (SO₂) with surface-bound compounds on atmospheric aerosols lead to the formation of organic sulfur (OS) compounds, thereby affecting the air quality and climate. Here, we show that the heterogeneous reaction of SO₂ with authentic urban grime under near-ultraviolet sunlight irradiation leads to a large suite of various organic compounds including OS released in the gas phase…

B. Streckenbach, M. Osswald, S. Malesevic, R. Zenobi, and M. Kohler

Chemical analysis of exhaled breath have suggested the existence of an OSA-specific metabolic signature. Here, we validated this diagnostic approach and the proposed marker compounds, as well as their potential to reliably diagnose OSA.

Jérôme Kaeslin, Cedric Wüthrich, Stamatios Giannoukos, and Renato Zenobi

Secondary electrospray ionization (SESI) is a soft ionization method, which is important to avoid interference from in-source fragments and to simplify compound annotation. In this work, it is shown that SESI is softer than electrospray ionization (ESI), and therefore, SESI indeed qualifies as a soft ionization technique. However…

Jérôme Kaeslin, Cedric Wüthrich, Stamatios Giannoukos, Renato Zenobi

It is a set of accompanying files for the publication "How soft is secondary electrospray ionization?".

A. Gómez-Mejia, K. Arnold, J. Bär, K. Dev Singh, T. C. Scheier, S. D. Brugger, A. S. Zinkernagel, P. Sinues

Early detection of pathogenic bacteria is needed for rapid diagnostics allowing adequate and timely treatment of infections.