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Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment consists of classifying breath samples from 15 subjects before and after eating a specific meal using three instruments. We investigate the possibility to transfer calibration models across instruments using transfer samples from the experiment under study, since representative samples of human breath at some conditions are difficult to simulate in a laboratory. For example, exhaled breath from subjects suffering from a disease for which the biomarkers are mostly unknown. Results show that many transfer samples of all the classes under study (in our case meal/no meal) are needed, although some CT methods present reasonably good results with only one class., publishedVersion

Currently, standard samples of hydrogen-metal systems meeting the requirements of glow discharge optical emission spectrometers (GD-OES) are not available on the market. This article describes the preparation of Zr-Nb-H standard samples and the calibration of GD-OES with the usage of these samples. Samples of Zr-2.5Nb were chosen as the material for sample production. The creation procedure includes five main steps: sample preparation (polishing to an average roughness, Ra, of 0.04 m using sandpaper), annealing, hydrogenation, maintenance in an inert gas atmosphere, and characterization of the samples. The absolute hydrogen concentration in the samples was determined volumetrically and calculated from the weight change. The distribution of hydrogen was studied using GD-OES Profiler 2 by Jobin Yvon Emission Horiba Group. As a result of this work, calibration curves of Zr, H, Nb, O, and other elements were obtained. The calibration errors were in the range of 1–5%.