Common Strategies and Factors Affecting Off-Line Breath Sampling and Volatile Organic Compounds Analysis Using Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS)

Abstract

An analysis of exhaled breath enables specialists to noninvasively monitor biochemical processes and to determine any pathological state in the human body. Breath analysis holds the greatest potential to remold and personalize diagnostics; however, it requires a multidisciplinary approach and collaboration of many specialists. Despite the fact that breath is considered to be a less complex matrix than blood, it is not commonly used as a diagnostic and prognostic tool for early detection of disordered conditions due to its problematic sampling, analysis, and storage. This review is intended to determine, standardize, and marshal experimental strategies for successful, reliable, and especially, reproducible breath analysis

GC-MS-based metabolomics of volatile organic compounds in exhaled breath: applications in health and disease. A review

“…TD were the most utilized pre-concentration technique, followed by SPME ( Figure 6C ), consistent with previous reviews ( Lawal et al, 2017 ; Westphal et al, 2023 ). The widespread use of TD can be attributed to their suitability for long-term sample storage, ease of transport, and the stability of the entrapped compounds.…”

“…The most common collection device was Tedlar ® bags ( Figure 6B ), consistent with previous reviews ( Lawal et al, 2017 ; Westphal et al, 2023 ). While these bags are subject to contamination and have limited sample storage time, they are affordable and reusable, with several cleaning protocols available ( Westphal et al, 2023 ). Additionally, devices such as Bio-VOC ® , breath-gas sampler, and ReCIVA are gaining popularity, although they are not as widely used.…”

“…Additionally, carbon-based materials like Carboxen were employed. These alternatives offer a narrower range (C3–C20 and C2–C5), although they facilitate the capture of low-molecular-weight and more volatile compounds ( Lawal et al, 2017 ; Westphal et al, 2023 ). Many studies have employed multi-bed sorbents, with the most prevalent being Carbograph 1TD/Carbopack X.…”

“…The analysis of blanks allows for the identification of contaminants (e.g., Tedlar ® bag contaminants) and artifacts (e.g., polydimethylsiloxanes), and its elimination from the data matrix, avoiding false discoveries. The main blanks include collecting device blank, air blank, and vial/tube blank ( Westphal et al, 2023 ). In this regard, several studies have reviewed and conducted analyses of ambient air, yet a considerable number of studies do not include this step, such as that of Gao et al (2016) , Aoki et al (2017) , Van Vliet et al (2017) , and Saidi et al (2020) .…”

Influence of ventilatory parameters on the concentration of exhaled volatile organic compounds in mechanically ventilated patients

“…[22][23][24] When using gas chromatography-mass spectrometry (GC-MS), a step of pre-concentration is normally carried out by means of thermal desorption (TD), solid-phase microextraction (SPME) or needle trap devices (NTD). [25][26][27] With direct injection methods, pre-concentration is instead not required.…”