Short-chain fatty acids (SCFAs) are key volatile biomarkers in breath for non-invasive disease detection, but methanol-driven esterification during thermal desorption workflows can convert SCFAs into methyl esters, leading to substantial loss of parent acids and distorted biomarker measurements. Here, the authors show that this reaction occurs in the liquid phase and accelerates with higher temperatures and prolonged storage, highlighting the need for improved protocols to ensure accurate VOC-based diagnostics.
- Philip Kwan Hung Leung
- Alson Hubert Kwongyiu Wong
- Ilaria Belluomo
