Validation of a sensor system for the measurement of breath ammonia using selected-ion flow-tube mass spectrometry

Wagner, Michal; Saad, Saliha; Killard, Tony

Abstract

The measurement of trace breath gases is of growing interest for its potential to provide non-invasive physiological information in health and disease. While instrumental techniques such as selected-ion flow-tube mass spectrometry (SIFT-MS) can achieve this, these are less suitable for clinical application. Sensitive sensor-based systems for breath ammonia could be more widely deployed, but have proven challenging to develop. This work demonstrates the sequential analytical validation of an electrochemical impedance-based sensor system for the measurement of ammonia in breath using SIFT-MS. Qualitative and relative responses between the two methods were comparable, although there were consistent differences in absolute concentration. When tested in artificial breath ammonia, sensors had a relative impedance sensitivity of 3.43x10−5 ppbv−1 for each breath in the range of 249 to 1,653 ppbv (r2=0.87, p<0.05). When correlated with SIFT-MS using human breath (n=14), ammonia was detected in the range of 100 to 700 ppbv (r=0.78, p<0.001), demonstrating acceptable sensitivity, reproducibility and dynamic range for clinical application.

• Journal Article Type: Article
• Acceptance Date: Nov 4, 2024
• Online Publication Date: Nov 14, 2024
• Publication Date: Jan 31, 2025
• Deposit Date: Nov 5, 2024
• Publicly Available Date: Nov 15, 2025
• Journal: Journal of Breath Research
• Print ISSN: 1752-7155
• Electronic ISSN: 1752-7163
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 19
• Issue: 1
• Article Number: 016006
• DOI: https://doi.org/10.1088/1752-7163/ad8e7d
• Keywords: ammonia, Mass Spectrometry - instrumentation - methods, sensor, breath, Ammonia - analysis, Humans, Breath Tests - instrumentation - methods, Reproducibility of Results, selected-ion flow-tube mass spectrometry
• Public URL: https://uwe-repository.worktribe.com/output/13395165