Fig. 2.

Region comparison image of MCC-IMS analyses of bacterial volatiles. Only monomeric MCC-IMS signals are shown. Red boxes indicate the presence of a VOC, which can be used for bacterial discrimination. Signals from 1 to 14 have been determined in positive ion mode, whereas signals from 17 to 29 have been determined in negative ion mode. An example of headspace VOCs of sheep blood agar and one example of headspace of every bacterial strain is displayed. All strains have been cultivated for 24 h. Signal intensities are illustrated by different colours (white = zero, blue = low, red = medium, yellow = high). The following signals have been used for further analyses: 1 ethanol, 2 indole, 3 phenethyl alcohol, 4 p_649_194, 5 p_675_194, 6 p_679_429, 7 p_700_423, 8 p_711_3, 9 p_749_26, 10 p_749_37, 11 p_771_54, 13 p_793_19, 14 p_794_12, 17 phenethyl alcohol, 18 p_493_17, 19 p_543_12, 20 p_563_24, 21 p_572_8, 22 2-(methylthio)-ethanol, 25 indole, 26 p_629_10, 27 p_654_20, 28 p_681_36 and 29 p_688_22