A Workflow For The Metabolomic/Metabonomic Investigation of Exhaled Breath Using Thermal Desorption Gc–Ms

Abstract

This approach facilitated more efficient data modeling and a case study from a 22-participant (10 male, 12 female) stress-intervention experiment. Principal component analysis of data registered by retention indexing did not classify successfully stressed from unstressed states. By contrast, adoption of a breath matrix approach enabled 95% separation.

Metabolomics Pilot Study to Identify Volatile Organic Compound Markers of Childhood Asthma in Exhaled Breath

“…Written informed consent was obtained from participants and parents. The apparatus and workflow used in this study have been reported previously [4,15,16].…”

“…Furthermore, the experimental challenge of obtaining reproducible samples from children at different stages of lung-development has not been clearly addressed. The technical challenges of reproducible and safe breath sampling have been discussed recently [4] where the use of adaptive sampling based on the continuous monitoring of the breathing patterns of a participant with the same portion of each breath sampled was emphasized. Achieving this necessitated the use of a full face mask to provide a consistent and reproducible air supply, and a consistent and reproducible sampling operation.…”

“…One useful text book is an excellent introduction to the range of approaches currently under consideration and encompasses: selected ion flow tube MS; IMR-MS; protontransfer TOF-MS; ion mobility spectrometry; laser-based methods, and sensors and sensor array approaches [2]. This study with asthmatic children is based on GC-MS approaches [3,4].…”

How long may a breath sample be stored for at −80 °C? A study of the stability of volatile organic compounds trapped onto a mixed Tenax:Carbograph trap adsorbent bed from exhaled breath

“…The sampling method and analysis workflow has been described previously [12,13] Figure 1. It is important to note that the participant was supported and encouraged to remain in a quiet and relaxed state throughout the whole sampling procedure.…”

“…The data processing workflow adopted has been described previously [15]. Briefly, the TD-GC-MS data were deconvoluted (AnalyzerPro Spectral Works, UK), and a typical breath sample was found to contain approximately 500 resolvable compounds.…”