The peppermint breath test benchmark for PTR-MS and SIFT-MS

Abstract

A major challenge for breath research is the lack of standardization in sampling and analysis. To address this, a test that utilizes a standardized intervention and a defined study protocol has been proposed to explore disparities in breath research across different analytical platforms and to provide benchmark values for comparison. Specifically, the Peppermint Experiment involves the targeted analysis in exhaled breath of volatile constituents of peppermint oil after ingestion of the encapsulated oil. Data from the Peppermint Experiment performed by proton transfer reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS) are presented and discussed herein, including the product ions associated with the key peppermint volatiles, namely limonene, α-and β-pinene, 1,8-cineole, menthol, menthone and menthofuran. The breath washout profiles of these compounds from 65 individuals were collected, comprising datasets from five PTR-MS and two SIFT-MS instruments. The washout profiles of these volatiles were evaluated by comparing the log-fold change over time of the product ion intensities associated with each volatile. Benchmark values were calculated from the lower 95% confidence interval of the linear time-to-washout regression analysis for all datasets combined. Benchmark washout values from PTR-MS analysis were 353 min for the sum of monoterpenes and 1,8-cineole (identical product ions), 173 min for menthol, 330 min for menthofuran, and 218 min for menthone; from SIFT-MS analysis values were 228 min for the sum of monoterpenes, 281 min for the sum of monoterpenes and 1,8-cineole, and 370 min for menthone plus 1,8-cineole. Large interand intra-dataset variations were observed, whereby the latter suggests that biological variability plays a key role in how the compounds are absorbed, metabolized and excreted from the body via breath. This variability seems large compared to the influence of sampling and analytical procedures, but further investigations are recommended to clarify the effects of these factors.

A novel VOC breath tracer method to evaluate indoor respiratory exposures in the near- and far-fields; implications for the spread of respiratory viruses

“…These compounds were shown to be substantially elevated in exhaled breath of the participant when consuming a breath mint. We putatively identify the signal m/z 155.150 as protonated menthone and m/z 139.137 as dehydrated menthol [ 29 , 30 ]. Monoterpenes are a class of compounds that share the chemical formula C 10 H 16 ; our PTR-ToF-MS is unable to distinguish isomers.…”

Research Progress of Graphene and Its Derivatives towards Exhaled Breath Analysis

“… Traditional methods for monitoring breath biomarkers include gas chromatogra mphy–mass spectrometry (GC-MS) [ 16 ], selective ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) [ 17 ], ion mobility spectroscopy (IMS) [ 17 ], enzyme immunoassay [ 18 ], polymerase chain reaction, and new antibody microarray technology, etc. [ 19 ].…”

Increasing the Robustness of SIFT-MS Volatilome Fingerprinting by Introducing Notional Analyte Concentrations

“…Typically, data from large-scale SIFT-MS-based experiments is normalized into relative count rates by dividing each m/z abundance by the sum of the signal intensities per specific reagent ion. 23,24 We did notice, however, that this approach is not sufficient to address the prevailing variations, often resulting in inconsistent product:reagent ion ratios.…”

“…In the case of internal standards the difficulty is because of the lack of chromatographic separation and in the case of quality control samples it is because of working with intact perishable biological samples. Typically, data from large-scale SIFT-MS-based experiments is normalized into relative count rates by dividing each m / z abundance by the sum of the signal intensities per specific reagent ion. , We did notice, however, that this approach is not sufficient to address the prevailing variations, often resulting in inconsistent product:reagent ion ratios.…”