Volatile organic compounds in a headspace sampling system and asthmatics sputum samples

Visualization of exhaled breath metabolites reveals distinct diagnostic signatures for acute cardiorespiratory breathlessness

Acute cardiorespiratory breathlessness accounts for one in eight of all emergency hospitalizations. Early, noninvasive diagnostic testing is a clinical priority that allows rapid triage and treatment. Here, we sought to find and replicate diagnostic breath volatile organic compound (VOC) biomarkers of acute cardiorespiratory disease and understand breath metabolite network enrichment in acute disease, with a view to gaining mechanistic insight of breath biochemical derangements. We collected and analyzed exhaled breath samples from 277 participants presenting acute cardiorespiratory exacerbations and aged-matched healthy volunteers. Topological data analysis phenotypes differentiated acute disease from health and acute cardiorespiratory exacerbation subtypes (acute heart failure, acute asthma, acute chronic obstructive pulmonary disease, and community-acquired pneumonia). A multibiomarker score (101 breath biomarkers) demonstrated good diagnostic sensitivity and specificity (≥80%) in both discovery and replication sets and was associated with all-cause mortality at 2 years. In addition, VOC biomarker scores differentiated metabolic subgroups of cardiorespiratory exacerbation. Louvain clustering of VOCs coupled with metabolite enrichment and similarity assessment revealed highly specific enrichment patterns in all acute disease subgroups, for example, selective enrichment of correlated C5-7 hydrocarbons and C3-5 carbonyls in heart failure and selective depletion of correlated aldehydes in acute asthma. This study identified breath VOCs that differentiate acute cardiorespiratory exacerbations and associated subtypes and metabolic clusters of disease-associated VOCs.

Efficient identification of raw and ripe tung oil using headspace GC-MS

To differentiate between the raw type and ripe type of tung oil, it is important to distinguish between the types of tung oil before its application. In the present work, an efficient headspace gas chromatography-mass spectrometry (HS-GC-MS) method was developed for identifying eight samples T1-T8, including the raw tung oil and ripe tung oil. The HS-GC-MS experiments results showed that octanoic acid existed only in ripe tung oil of T2, T4, T6, T8, not in raw tung oil of T1, T3, T5, T7. Combined with structural characterization by tandem mass spectrometry, octanoic acid was screened as an effective marker for distinguishing between raw tung oil and ripe tung oil. Then, the HS-GC-MS method was applied into the putty samples of X1 (raw tung oil with lime) and X2 (ripe tung oil with lime) and successfully identified the samples X1 mixed with raw tung oil and X2 mixed with ripe tung oil. The further validations results suggested that the detection limit of our HS-GC-MS method could reach 1.05 mg/L for octanoic acid, whereas the detection limit of derivative gas chromatography-mass spectrometry (DR-GC-MS) method was 2.74 mg/L for methyl octanoate. The investigation results can also provide the useful information and technical support for the selection of restoration materials and technology in ancient buildings.

Pursuing breath research in unprecedented circumstances-report from the Breath Biopsy Conference 2020

The global outbreak of Sars-CoV-2 commencing early in 2020 had a dramatic impact on breath research, imposing abrupt restrictions but also presenting unforeseen opportunities. Taking place against the background of the COVID-19 pandemic, the 2020 Breath Biopsy Conference provided the breath research community with a platform to showcase and discuss the latest findings, including COVID-19 related research. As with most conferences under the present circumstance, it differed from its predecessor meetings by shifting to a virtual format, but retained its broad scope and interactive nature. The conference centred on four key themes, featuring applications of volatile organic compounds, breath biomarkers for liver disease, study design and data analytics, and, notably this year, breath-based endeavours to detect COVID-19 infection. This meeting report summarizes the events of the conference and spotlights selected contributions.