Xue Li, Lei Huang, Hui Zhu and Zhen Zhou.

RATIONALE: Direct mass spectrometry (MS)-based methods make it possible to monitor the molecular compositions of hundreds of volatile organic compounds (VOCs) in exhaled human breath in real time. Mass resolution and mass accuracy play important roles for direct MS analysis, especially for the low-concentration isobaric compounds in non-target research.

D. García-Gómez, T. Gaisl, L. Bregy, A. Cremonesi, P. M-L Sinues, M. Kohler, and R. Zenobi

Amino acids are frequently determined in clinical chemistry. However, current analysis methods are time-consuming, invasive, and require sample preparation. The authors hypothesized that plasma concentrations of amino acids can be estimated by measuring their concentrations in exhaled breath.

D. García-Gómez, T. Gaisl, L. Bregy, P. M-L Sinues, M. Kohler and R. Zenobi

Disorders in tryptophan metabolism result in diseases such as vitamin B6 responsive xanthurenic aciduria, hydroxy-kynureninuria, tryptophanuria and Hartnup disease. The authors hypotesized that breath analysis may reveal compounds that are metabolically linked to tryptophan. The mass range of detected metabolites reached up to 265 u, which is beyond the mass range limit (150–200 u) of competing breath research techniques such as PTR or SIFT-MS.

G. Trecate, P. M-L Sinues & R. Orlandi

Breast cancer screening and presurgical diagnosis are currently based on mammography, ultrasound and more sensitive imaging technologies; however, noninvasive biomarkers represent both a challenge and an opportunity for early detection of cancer …

M. T. Gaugg, D. Garcia Gomez, C. Barrios-Collado, G. Vidal-de-Miguel, M. Kohler, R. Zenobi and P. M-L Sinues

Coupling a SESI source and a HRMS (Orbitrap), the authors were able to identify exogenous compounds associated to smoking, as well as endogenous metabolites suggesting increased oxidative stress in smokers. According to the authors, most of these compounds correlated significantly with smoking frequency and allowed accurate discrimination of smokers and non-smokers.

D. Garcia-Gomez, T. Gaisl, C. Barrios-Collado, Guillermo Vidal-de-Miguel, M. Kohler and R. Zenobi

Chemical analysis of aerosols collected from electronic cigarettes (ECs) has shown that these devices produce vapors that contain harmful and potentially harmful compounds. Conventional analytical methods used for the analysis of electronic cigarettes do not reflect the actual composition of the aerosols generated because they usually neglect the changes in the chemical composition that occur during the aerosol generation process and after collection.

E. I Schwarz, P. M-L Sinues, L. Bregy, T. Gaisl, D. Garcia-Gomez, M. T. Gaugg, Y. Suter, N. Stebler, Y. Nussbaumer-Ochsner, K. E. Bloch, J. R. Stradling, R. Zenobi, M. Kohler

Patients with OSA effectively treated with CPAP were randomised to either withdraw treatment or continue CPAP for 2 weeks. Exhaled breath analysis and research by untargeted SESI-MS was performed at baseline and 2 weeks after randomisation. CPAP withdrawal led to a recurrence of OSA, which was accompanied by a significant change in 16 identified metabolites.

P. M-L Sinues, Elena Landoni, Rosalba Miceli, Vincenza F. Dibari, Matteo Dugo, Roberto Agresti, Elda Tagliabue, Simone Cristoni, Rosaria Orlandi.

SESI–MS produces high-dimensional data of quality comparable to gene expression analysis output. This prompted the authors to use methods originally developed for gene expression data in analyzing SESI–MS breathprints.

D. García-Gómez, L. Bregy, Y. Nussbaumer-Ochsner, T. Gaisl, M. Kohler, and R. Zenobi

2-Subtituted benzothiazoles are widely used industrial chemicals whose occurrence in environmental samples has been shown to be ubiquitous. However, knowledge about human exposure to these compounds and their excretion route is still scarce. Here, we demonstrate for the first time the detection of benzothiazole derivatives in exhaled breath.

D. García-Gómez, L. Bregy, C. Barrios-Collado, G. Vidal-de-Miguel and R. Zenobi

The identification of chemical compounds in exhaled human breath is promising in the search for new biomakers of diseases. However, the analytical techniques used nowadays are not capable of achieving a robust identification, especially in real-time analysis.

Xue Li, P. M-L Sinues, R. Dallmann, L. Bregy, M.Hollmén, S. Proulx, S. A. Brown, M. Detmar, M. Kohler, and R. Zenobi

Noninvasive, real-time pharmacokinetic (PK) monitoring of ketamine, propofol, and valproic acid, and their metabolites was achieved in mice, using secondary electrospray ionization and high-resolution mass spectrometry. The PK profile of a drug influences its efficacy and toxicity because it determines exposure time and levels …

D. García-Gómez, P. M.-L. Sinues, C. Barrios-Collado, G. Vidal-de Miguel, M. Gaugg, and R. Zenobi

In recent years, breath analysis in real time has become a noninvasive alternative for the diagnosis of diseases and for molecular fingerprinting of exhaled breath. However, the techniques used lack the capabilities for proper identification of the compounds found in the exhalome.

P. M-L Sinues, L. Tarokh, Xue Li, M. Kohler, S. A. Brown, R. Zenobi, R. Dallmann

Circadian clocks play a significant role in the correct timing of physiological metabolism, and clock disruption might lead to pathological changes of metabolism. One interesting method to assess the current state of metabolism is metabolomics. Metabolomics tries to capture the entirety of small molecules, i.e. the building blocks of metabolism, in a given matrix …

J-C Wolf, M. Schaer, P. Siegenthaler, R. Zenobi

A novel active capillary dielectric barrier discharge plasma ionization (DBDI) technique for mass spectrometry is applied to the direct detection of thirteen chemical warfare related compounds, including sarin, and compared to secondary electrospray ionization (SESI) in terms of selectivity and sensitivity. The investigated compounds include an intact chemical warfare agent and structurally related molecules, hydrolysis products and/or precursors of highly toxic nerve (G-series, V-series and "new" nerve agents), blistering and incapacitating warfare agents. …

P. M-L Sinues, L. Meier, C. Berchtold, M.Ivanov, N. Sievi, G. Camen, M. Kohler, R. Zenobi

Background: It has been suggested that exhaled breath contains relevant information on health status. Objectives: We hypothesized that a novel mass spectrometry (MS) technique to analyze breath in real time could be useful to differentiate breathprints from chronic obstructive pulmonary disease (COPD) patients and controls (smokers and nonsmokers) …

P. M-L Sinues, R. Zenobi, M. Kohler

Investigations on breath analysis have provided preliminary data on its potential in the noninvasive diagnosis of lung diseases. Although the conventional comparisons of exhaled breath in study populations (ie, diseased vs healthy) may help to identify patients with various lung diseases, we believe that the analysis of exhaled breath holds promise beyond this scenario …

C. Berchtold, L. Meier, R. Steinhoff, R. Zenobi

Breath is considered to be an easily accessible matrix, whose chemical composition relates to compounds present in blood. Therefore many metabolites are expected in exhaled breath, which may be used in the future for the development of diagnostic methods. In this article, a new strategy to discriminate between exhaled endogenous metabolites and exhaled exogenous contaminants by direct high-resolution mass spectrometry is introduced.

P. M.-L. Sinues, M. Kohler, R. Zenobi

The metabolic phenotype varies widely due to external factors such as diet and gut microbiome composition, among others. Urine metabolite profiling studies have suggested that there are highly individual phenotypes that persist over extended periods of time. This hypothesis was tested by analyzing the exhaled breath of a group of subjects during nine days by mass spectrometry.

J. Zhu, H. D. Bean, J. Jiménez-Díaz, and J. E. Hill

Bacterial pneumonia is one of the leading causes of disease-related morbidity and mortality in the world, in part because the diagnostic tools for pneumonia are slow and ineffective. To improve the diagnosis success rates and treatment outcomes for bacterial lung infections, we are exploring the use of SESI-MS breath analysis as a rapid, noninvasive method for determining …

P. M-L Sinues, M. Kohler and R. Zenobi

The development of noninvasive analytical techniques is of interest to the field of chronobiology, in order to reveal the human metabolome that seems to show temporal patterns and to predict internal body time. We report on the real-time mass spectrometric analysis of human breath as a potential method to be used in this field.