Generating pooled quality control samples of volatile organic compounds.

Untargeted analysis of volatile organic compounds (VOCs) from exhaled breath and culture headspace can be influenced by several confounding factors that are not reflected in reference standards. In this study, we propose a method to generating pooled quality control (QC) samples for untargeted VOC studies using a split-recollection workflow for thermal desorption tubes. Sample tubes were desorbed with a 10% split from each sample and recollected onto a single tube, generating a pooled QC sample. This QC sample was then repeatedly desorbed and recollected with a sequentially lower split ratio allowing injection of up to ten QC samples. We found pooled QC samples to be representative of complex mixtures using principal component analysis (PCA) and may be useful in future longitudinal, multi-centre, and validation studies to assess data quality and adjust for batch effects.