Fig. 3

Direct and exemplary comparison of IMS chromatogram sections (two-dimensional view, different retention times are displayed in one plane) of inspired gas from respirator (directed downwards) and patient’s exhalome (directed upwards). Intensities of the selected exhaled compounds (peak heights) are considerably greater than inhaled concentrations. RIP = Reactant Ion Peak (Ionization of nitrogen and oxygen forms reactant ions and are always detectable, regardless of contamination)