Table 1. Percentage occurrences of volatiles found to show statistically significant differences in occurrence between disease and control groups.
Compounds / % presentAlcoholic cirrhosis (n = 34)
with HE (n = 11) / no HE (n = 23) / with & without HE / Non-alcoholic cirrhosis, no HE (n= 13) / Harmful drinking, no cirrhosis (n = 7) / Healthy (n = 15)
acetophenone / 81.8 / 52.2 / 61.8f3 / 84.6 / 71.4 / 93.3f3
allyl methyl sulfide / 45.5 / 34.8 / 38.2c3 / 23.1 / 0.0c3 / 33.3
benzaldehyde / 100.0 / 82.6 / 88.2f2 / 76.9 / 100.0d3 / 53.3d3, f2
benzene / 90.9 / 100.0 / 97.1f1 / 84.6 / 85.7 / 60.0f1
2,3-butanedione / 72.7 / 47.8 / 55.9f2 / 46.2 / 42.9 / 13.3f2
1-butanol / 54.5 / 82.6 / 73.5 / 100.0e2 / 100.0d3 / 53.3d3, e2
2-butanol / 54.5 / 21.7 / 32.4f3 / 7.7 / 28.6 / 0.0f3
2-butanone / 100.0 / 91.3 / 94.1f1 / 76.9 / 100.0d3 / 53.3d3, f1
2-(2-butoxyethoxy)-ethanol* / 9.1 / 8.7 / 8.8c3 / 7.7 / 42.9c3, d3 / 6.7d3
camphene / 63.6 / 56.5 / 58.8c3,f1 / 53.8e2 / 14.3c3 / 6.7e2, f1
camphor / 81.8 / 47.8 / 58.8c2,f3 / 23.1 / 0.0c2 / 20.0f3
cyclohexanol / 36.4a3 / 4.3a3 / 14.7 / 0.0 / 28.6 / 0.0
cyclohexanone / 45.5a2 / 4.3a2 / 17.6 / 0.0 / 14.3 / 0.0
2,4-dimethylfuran / 0.0 / 13.0 / 8.8c3 / 15.4 / 42.9c3, d3 / 6.7d3
2,5-dimethylfuran / 45.5 / 43.5 / 44.1 / 61.5e3 / 71.4d3 / 20.0d3, e3
3,7-dimethyl-1,6-octadien-3-ol* / 72.7 / 60.9b2 / 64.7c3,f3 / 15.4b2 / 14.3c3 / 26.7f3
2,6-dimethyl-7-octen-2-ol* / 36.4 / 60.9 / 52.9f2 / 30.8 / 71.4d1 / 6.7d1, f2
2-ethylfuran / 54.5 / 34.8 / 41.2f2 / 46.2e2 / 57.1d1 / 0.0d1, e2, f2
3-ethylhexane / 36.4a3 / 8.7a3 / 17.6 / 0.0 / 14.3 / 0.0
2-ethylhexanoic acid* / 9.1 / 34.8b3 / 26.5 / 0.0b3 / 28.6 / 0.0
2-ethyl-1-hexanol / 27.3 / 47.8 / 41.2c2 / 53.8 / 100.0c2,d2 / 40.0d2
2-ethyl-5-methylfuran / 18.2 / 39.1 / 32.4f3 / 38.5e2 / 71.4d1 / 0.0d1, e2, f3
eucalyptol / 90.9 / 73.9 / 79.4 / 92.3e3 / 71.4 / 60.0e3
2,4-heptadien-1-ol* / 0.0 / 17.4 / 11.8c2 / 38.5e3 / 57.1c2, d2 / 6.7d2, e3
heptanal / 9.1a3 / 43.5a3 / 32.4 / 23.1 / 57.1d2 / 6.7d2
heptane / 90.9 / 100.0 / 97.1f1 / 84.6 / 85.7 / 53.3f1
2-heptanone / 81.8 / 69.6 / 73.5f1 / 38.5e2 / 57.1d1 / 0.0d1,e2, f1
hexadecane / 54.5a2 / 13.0a2 / 26.5 / 7.7 / 0.0 / 20.0
hexanal / 63.6 / 65.2 / 64.7f2 / 53.8 / 85.7d2 / 20.0d2,f2
isothiocyanatocyclohexane* / 100.0a2 / 43.5a2 / 61.8f2 / 15.4 / 42.9 / 20.0f2
2-methyl-1-butanol / 18.2a3 / 0.0a3 / 5.9 / 7.7 / 0.0 / 0.0
2-methyl-3-buten-2-ol / 81.8 / 60.9b2 / 67.6c1,f1 / 15.4b2 / 0.0c1 / 6.7f1
1-methyl-1,4-cyclohexadiene / 0.0 / 13.0 / 8.8c3 / 15.4 / 42.9c3, d2 / 0.0d2
2-methylfuran / 81.8 / 82.6 / 82.4f1 / 76.9e2 / 71.4d3 / 26.7d3, e2, f1
3-methylfuran / 18.2 / 60.9b3 / 47.1c2 / 92.3b3 / 100.0c2 / 73.3
3-methylheptane / 72.7 / 47.8 / 55.9f1 / 23.1 / 28.6 / 6.7f1
6-methyl-5-hepten-2-one / 36.4 / 52.2b2 / 47.1f3 / 7.7b2 / 85.7d1 / 13.3d1, f3
2-methylhexane / 54.5 / 47.8 / 50.0f3 / 23.1 / 57.1d3 / 13.3d3, f3
1-methyl-4-(1-methylethenyl)-benzene / 63.6 / 69.6b3 / 67.6c2,f1 / 30.8b3, e3 / 14.3c2 / 0.0f1, e3
1-methyl-2-(1-methylethyl)-benzene / 100.0 / 95.7 / 97.1f1 / 100.0e1 / 85.7d2 / 26.7d2, e1, f1
1-methyl-4-(1-methylethyl)-1,4-cyclohexadiene / 72.7 / 56.5 / 61.8f2 / 69.2e2 / 28.6 / 13.3e2, f2
1-methyl-4-(1-methylethyl)-cyclohexene / 36.4 / 26.1b3 / 29.4c3 / 61.5b3, e2 / 71.4c3, d1 / 6.7d1, e2
1-methyl-4-(1-methylethylidene)-cyclohexene / 72.7 / 39.1 / 50.0c3,f1 / 23.1 / 0.0c3 / 0.0f1
3-methylpentane / 100.0 / 87.0 / 91.2f3 / 92.3 / 85.7 / 66.7f3
4-methyl-Z-2-pentene / 54.5 / 65.2 / 61.8f3 / 84.6e2 / 71.4d3 / 26.7d3, e2, f3
methyl vinyl ketone / 9.1a3 / 52.2a3 / 38.2f1 / 53.8e3 / 57.1d3 / 93.3d3, e3, f1
nonadecane / 27.3 / 39.1b2 / 35.3f3 / 84.6b2 / 71.4 / 73.3f3
1-nonene / 27.3 / 56.5 / 47.1 / 46.2 / 85.7d2 / 26.7d2
nonylbenzene / 27.3a2 / 0.0a2 / 8.8 / 0.0 / 0.0 / 0.0
octanal / 54.5 / 60.9 / 58.8c3,f3 / 53.8 / 100.0c3,d1 / 20.0d1, f3
pentanal / 0.0 / 17.4 / 11.8c3 / 15.4 / 42.9c3 / 13.3
pentane / 90.9 / 100.0 / 97.1f2 / 100.0e3 / 100.0 / 66.7e3, f2
2-pentylfuran / 72.7 / 43.5b2 / 52.9f2 / 0.0b2 / 42.9 / 13.3f2
phellandrenei 24.93 / 54.5 / 30.4 / 38.2c3,f2 / 7.7 / 0.0c3 / 0.0f2
phellandrenei 26.24 / 90.9 / 78.3 / 82.4f1 / 53.8e1 / 57.1d1 / 0.0d1, e1, f1
phenol / 81.8 / 78.3b3 / 79.4 / 46.2b3 / 85.7 / 73.3
2-phenoxyethanol / 18.2 / 34.8 / 29.4 / 23.1 / 42.9d3 / 6.7d3
1-R-a-pinene / 100.0 / 100.0 / 100.0f1 / 100.0e3 / 100.0 / 66.7e3, f1
propylbenzene / 72.7 / 82.6 / 79.4f1 / 61.5e3 / 85.7d2 / 20.0d2, e3, f1
undecane / 81.8 / 78.3b2 / 79.4f1 / 30.8b2 / 85.7d2 / 20.0d2, f1
unknown 6.16 / 27.3 / 13.0 / 17.6 / 38.5e3 / 42.9d3 / 6.7d3, e3
unknown 6.50 / 0.0 / 4.3b3 / 2.9 / 30.8b3, e3 / 14.3 / 0.0e3
unknown 8.59 / 27.3 / 52.2 / 44.1c3 / 69.2e2 / 85.7c3, d2 / 20.0d2, e2
unknown 9.39Θ / 0.0 / 8.7b3 / 5.9c1 / 38.5b3, e2 / 57.1c1, d1 / 0.0d1, e2
unknown 9.74 / 18.2 / 26.1 / 23.5 / 30.8 / 0.0d3 / 40.0d3
unknown 10.08 / 9.1 / 8.7 / 8.8c3 / 30.8 / 42.9c3 / 13.3
unknown 10.43Θ / 9.1 / 17.4 / 14.7c1 / 46.2e2 / 71.4c1, d1 / 0.0d1, e2
unknown 10.53 / 9.1 / 21.7b3 / 17.6 / 61.5b3, e1 / 42.9d2 / 0.0d2, e1
unknown 10.61Θ / 0.0 / 26.1b3 / 17.6c3 / 69.2b3, e1 / 57.1c3, d1 / 0.0d1, e1
unknown 10.67 / 0.0 / 17.4 / 11.8 / 38.5e2 / 28.6 / 0.0e2
unknown 10.75 / 9.1 / 30.4 / 23.5c3 / 53.8e3 / 71.4c3, d2 / 13.3d2, e3
unknown 10.88 / 0.0 / 21.7 / 14.7 / 30.8e3 / 14.3 / 0.0e3
unknown 11.10 / 9.1 / 21.7 / 17.6c3 / 38.5 / 57.1c3, d3 / 13.3d3
unknown 11.61 / 45.5 / 47.8 / 47.1 / 61.5 / 85.7d2 / 26.7d2
unknown 12.08 / 18.2 / 26.1 / 23.5 / 30.8 / 57.1d3 / 13.3d3
unknown 13.76 / 36.4a3 / 8.7a3 / 17.6 / 0.0 / 0.0 / 0.0
unknown 14.17 / 18.2 / 21.7 / 20.6 / 38.5e3 / 42.9d3 / 6.7d3, e3
unknown 14.98 / 9.1 / 34.8 / 26.5 / 61.5e2 / 57.1d3 / 13.3d3, e2
unknown 15.17 / 63.6 / 39.1b3 / 47.1f3 / 7.7b3 / 14.3 / 13.3f3
unknown 17.53 / 0.0 / 21.7 / 14.7 / 38.5e2 / 42.9d2 / 0.0d2, e2
unknown 17.66 / 0.0 / 21.7 / 14.7c3 / 38.5e2 / 57.1c3, d1 / 0.0d1, e2
unknown 17.87 / 18.2 / 30.4b3 / 26.5 / 0.0b3 / 28.6 / 0.0
unknown 17.95 / 0.0 / 21.7 / 14.7 / 38.5e3 / 42.9d3 / 6.7d3, e3
unknown 18.90 / 9.1 / 8.7 / 8.8 / 30.8e3 / 28.6 / 0.0e3
unknown 19.60 / 18.2 / 30.4 / 26.5c3 / 46.2e3 / 71.4c3, d1 / 6.7d1, e3
unknown 19.96 / 9.1 / 26.1 / 20.6c2 / 38.5e3 / 71.4c2, d1 / 6.7d1, e3
unknown 21.18 / 45.5 / 47.8 / 47.1f1 / 30.8e3 / 14.3 / 0.0f1, e3
unknown 21.33 / 18.2 / 21.7 / 20.6 / 38.5e2 / 28.6 / 0.0e2
unknown 22.67 / 27.3 / 39.1 / 35.3f3 / 61.5e2 / 42.9d3 / 6.7d3, e2, f3
unknown 23.15 / 9.1 / 26.1 / 20.6c2 / 46.2 / 71.4c2, d2 / 13.3d2
unknown 23.55 / 100.0 / 82.6 / 88.2f3 / 69.2 / 71.4 / 60.0f3
unknown 23.60 / 54.5 / 34.8 / 41.2f2 / 23.1 / 14.3 / 0.0f2
unknown 23.73 / 100.0 / 95.7 / 97.1f1 / 84.6e2 / 85.7d3 / 33.3d3, e2, f1
unknown 23.95 / 100.0 / 95.7 / 97.1f1 / 84.6e3 / 85.7 / 46.7e3, f1
unknown 24.75 / 18.2 / 17.4 / 17.6c3 / 38.5e3 / 57.1c3, d2 / 6.7d2, e3
unknown 24.91 / 72.7 / 56.5 / 61.8f1 / 23.1 / 28.6 / 0.0f1
unknown 25.02 / 72.7 / 60.9 / 64.7c2,f3 / 38.5 / 0.0c2 / 33.3f3
unknown 25.09 / 27.3 / 26.1 / 26.5c3 / 46.2e3 / 71.4c3, d1 / 6.7d1, e3
unknown 25.38 / 72.7 / 43.5 / 52.9c2,f1 / 46.2e2 / 0.0c2 / 0.0e2, f1
unknown 26.04 / 27.3 / 21.7 / 23.5c3 / 7.7 / 71.4c3, d3 / 20.0d3
unknown 27.98 / 18.2a3 / 0.0a3 / 5.9 / 0.0 / 0.0 / 0.0
unknown 29.01 / 0.0 / 4.3b3 / 2.9 / 30.8b3 / 14.3 / 13.3
unknown 29.84 / 45.5 / 26.1 / 32.4f3 / 7.7 / 0.0 / 0.0f3
unknown 30.42 / 36.4a3 / 4.3a3 / 14.7 / 0.0 / 0.0 / 20.0
unknown 30.47 / 0.0 / 17.4 / 11.8c3 / 0.0 / 42.9c3, d2 / 0.0d2
unknown 31.18 / 18.2a3 / 0.0a3 / 5.9 / 0.0 / 0.0 / 0.0
unknown 31.31 / 18.2a3 / 0.0a3 / 5.9 / 0.0 / 0.0 / 0.0
unknown 31.64 / 72.7a3 / 34.8a3,b3 / 47.1f3 / 0.0b3 / 28.6 / 13.3f3
unknown 34.69 / 9.1 / 4.3 / 5.9c1 / 0.0 / 57.1c1, d3 / 13.3d3
unknown 35.67 / 72.7 / 56.5 / 61.8c3,f3 / 46.2 / 100.0c3,d1 / 26.7d1, f3
vinylfuran* / 9.1 / 26.1 / 20.6c2 / 53.8e3 / 71.4c2, d2 / 13.3d2, e3
*= Tentative assignment, i=unknown isomer of phellandrene.
Superscript symbols represent compounds that showed significant differences in presence or absence between: a patients with and without HE in alcoholic cirrhotics, b alcoholic and non-alcoholic cirrhotic patients with no HE, c alcoholic cirrhotic patients and harmful drinkers with no cirrhosis, d harmful drinkers with no cirrhosis and healthy controls, e non-alcoholic cirrhotic patients and healthy controls, f alcoholic cirrhotic patients and healthy controls. Superscript numbers indicate p-value as follows: 1 = ≤ 0.001, 2 = ≤ 0.01, 3 = ≤ 0.05.All unknown compounds were tentatively identified as hydrocarbons and those enabling differentiation between groups labeled with Θ had a molecular mass of 82 and chemical formula C6H10.