Fig. 2.

(A) Flow diagram of the detailed sample history, processing and data being recorded at every stage of breath collection and analysis to ensure high quality breath analysis. 1) Tube weights and number of heat cycles recorded to monitor sorbent integrity; 2) tube conditioning and batch blanks; 3) kit preparation; 4) ReCIVA breath collection using SOPs following comprehensive training, producing ReCIVA metadata; 5) dry purging and IS spiking; 6) daily instrument checks and analysis of samples and reference mixtures. (B) ReCIVA quality control data showing gated breath collection, controlling the breath fraction, flow rate and total volume. (C) Three chromatograms collected per sample including breath, room air and air supply by TD-GC×GC-FID/qMS.