Rosa A Sola-Martínez, Jiafa Zeng, Mo Awchi, Amanda Gisler, Kim Arnold, Kapil Dev Singh, Urs Frey, Manuel Cánovas Díaz, Teresa de Diego Puente, Pablo Sinues

Secondary electrospray ionization-high resolution mass spectrometry (SESI-HRMS) is an established technique in the field of breath analysis characterized by its short analysis time, as well as high levels of sensitivity and selectivity. Traditionally, SESI-HRMS has been used for real-time breath analysis, which requires subjects to be at the location of the analytical platform. Therefore, it limits the possibilities for an introduction of this methodology in day-to-day clinical practice. However, recent methodological developments have shown feasibility on the remote sampling of exhaled breath in Nalophan® bags prior to measurement using SESI-HRMS…

Fouad Choueiry, Rui Xu, Kelly Meyrath, Jiangjiang Zhu.

Secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS) is an innovative analytical technique for the rapid and non-invasive analysis of volatile organic compounds (VOCs). However, compound annotation and ion suppression in the SESI source has hindered feature detection, stability and reproducibility of SESI-HRMS in untargeted volatilomics.

Fouad Choueiry, Andrew Gold, Rui Xu, Shiqi Zhang and Jiangjiang Zhu.

The symbiotic relationship between the gut microbial population is capable of regulating numerous aspects of host physiology, including metabolism. Bacteria can modulate the metabolic processes of the host by feeding on nutritional components within the lumen and releasing bioactive components into circulation. Endogenous volatile organic compound (VOC) synthesis is dependent on the availability of precursors found in mammalian metabolism

Cedric Wüthrich, Stamatios Giannoukos, Renato Zenobi

Ion suppression is a known matrix effect in electrospray ionization (ESI), ambient pressure chemical ionization (APCI), and desorption electrospray ionization (DESI), but its characterization in secondary electrospray ionization (SESI) is lacking. A thorough understanding of this effect is crucial for quantitative applications of SESI, such as breath analysis. In this study, gas standards were generated by using an evaporation-based system to assess the susceptibility and suppression potential of acetone, deuterated acetone, deuterated acetic acid, and pyridine. Gas-phase effects were found to dominate ion suppression, with pyridine exhibiting the most significant suppressive effect, which is potentially linked to its gas-phase basicity. The impact of increased acetone levels on the volatiles from exhaled breath condensate was also examined…

Mo Awchi, Kapil Dev Singh, Patricia E Dill, Urs Frey, Alexandre N Datta, and Pablo Sinues.

Therapeutic drug monitoring (TDM) of medications with a narrow therapeutic window is a common clinical practice to minimize toxic effects and maximize clinical outcomes. Routine analyses rely on the quantification of systemic blood concentrations of drugs. Alternative matrices such as exhaled breath are appealing because of their inherent non-invasive nature. This is especially the case for pediatric patients. We have recently

Bettina Streckenbach

Metabolomics, or the comprehensive study of metabolites and involved processes, provides insights into the current physiological state of humans. In the clinical setting, the detection and quantification of specific metabolites has proven to be invaluable in diagnostic testing. Herein, body samples that are non-invasively accessible are of particular interest…

M.Z. Islam, S. Giannoukos, Räisänen, K. Wang, X. Ma, F. Wahl, R. Zenobi, M. Niu.

To date, the commonly used methods to assess rumen fermentation are invasive. Exhaled breath contains hundreds of volatile organic compounds (VOC) that can reflect animal physiological processes. In the present study, for the first time, we aimed to use a non-invasive metabolomics approach based on high-resolution mass spectrometry to identify rumen fermentation parameters in dairy cows

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.