Figure 3.

Use of PTR-TOF and PMF to discriminate odour of different individuals. (a) The total measured odour spectrum (X) from a group of three volunteers (black) and the mass spectral profiles identified by the PMF algorithm for a three-factor solution. (b) The time series of the measured odour (black) and the relative contributions of factor 1 (green), factor 2 (blue) and factor 3 (red) (G). (c) Which volunteers were connected to the instrument during the five-sampling period (electronic supplementary material).