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Sampling of volatile organic compounds (VOCs) has shown promise for detection of a range of diseases but results have proved hard to replicate due to a lack of standardization. In this work we introduce the 'Peppermint Initiative'. The initiative seeks to disseminate a standardized experiment that allows comparison of breath sampling and data analysis methods. Further, it seeks to share a set of benchmark values for the measurement of VOCs in breath. Pilot data are presented to illustrate the standardized approach to the interpretation of results obtained from the Peppermint experiment. This pilot study was conducted to determine the washout profile of peppermint compounds in breath, identify appropriate sampling time points, and formalise the data analysis. Five and ten participants were recruited to undertake a standardized intervention by ingesting a peppermint oil capsule that engenders a predictable and controlled change in the VOC profile in exhaled breath. After collecting a pre-ingestion breath sample, five further samples are taken at 2, 4, 6, 8, and 10 h after ingestion. Samples were analysed using ion mobility spectrometry coupled to multi-capillary column and thermal desorption gas chromatography mass spectrometry. A regression analysis of the washout data was used to determine sampling times for the final peppermint protocol, and the time for the compound measurement to return to baseline levels was selected as a benchmark value. A measure of the quality of the data generated from a given technique is proposed by comparing data fidelity. This study protocol has been used for all subsequent measurements by the Peppermint Consortium (16 partners from seven countries). So far 1200 breath samples from 200 participants using a range of sampling and analytical techniques have been collected. The data from the consortium will be disseminated in subsequent technical notes focussing on results from individual platforms., Journal of Breath Research, 14 (4), ISSN:1752-7155, ISSN:1752-7163

The present contribution is focused on the measurement of the analytical sensitivity attained in untargeted/targeted MS/MS experiments, performed using flow-modulator comprehensive 2D and 1D GC. The comprehensive 2D experiment was performed by diverting part of the high flow (circa 80%) to flush the accumulation loop (about 28 mL/min) to waste, to reduce the gas flow entering the ion source. 1D analyses were performed through: (i) unmodulated and (ii) single column applications. An equivalent temperature program was applied in the modulated and unmodulated analyses, while a faster one was employed in the single column one. In all application types, the (same) triple quadrupole instrument was operated in the full-scan and multiple reaction monitoring modes. A genuine sweet orange oil and the same sample spiked with 20 phytosanitary compounds were employed to reach the research objective. The results highlight the problems related to the flow modulation-MS combination. Specifically, it was found that sensitivity was on average three to four times higher in unmodulated and optimized single-column applications.

The present research description is focused on the evaluation of a high-speed triple quadrupole mass spectrometer, carried out under moderately fast gas chromatography conditions (analysis time: 17 min). The mass spectrometric system is capable of operation under high-speed GC conditions, in both full-scan (maximum scan speed: 20,000 amu/s) and multiple reaction monitoring modalities. Furthermore, the triple quadrupole system can generate full scan and multiple reaction monitoring data simultaneously, also in a very rapid manner. A fast method was developed for the: (i) qualitative analysis of untargeted Citrus essential oil compounds, and (ii) the quali/quantitative analysis of targeted ones, namely three preservatives (o-phenylphenol, butylated hydroxytoluene, butylated hydroxy-anisole). The mass spectrometric system generated a more-than-sufficient number of data points/peak for both identification and quantification purposes. The level of sensitivity, reached through the multiple-reaction-monitoring side of the analysis, widely exceeded the requirements of current legislation. Method validation, related to the targeted analysis, was performed considering precision of retention times, peak areas and ion ratios; limits of detection/quantification, and accuracy were also measured.