. 2015 Apr 27;10(4):e0123980. doi: 10.1371/journal.pone.0123980

Table 2. Retention times, regression coefficients, detection limits and concentration ranges of selected VOC marker substances from breath (a) and feces (b).

substance					VOC-concentration [ppbV]
	retention time	R²	LOD	LOQ	inoculated animals			non-inoculated animals
					43 measurements			45 measurements
a) breath	[min]	[/]	[ppbV]		25%	median	75%	25%	median	75%
1-Propanol	9.96	0.976	1.41	3.48	184	258	445	69	214	528
2-Butanone	10.95	0.993	0.19	0.36	0.39	0.54	0.68	0.48	0.67	0.95
Acetone	7.53	0.854	0.25	0.45	22.2	30	38.7	26.7	32.7	38.3
Benzene	12.44	0.994	0.50	1.06	^†	0.52	0.64	^†	0.58	0.75
Butanal, 2-methyl-	12.99	0.977	0.08	0.11	^†	^†	0.24	^†	0.33	0.57
Ethylbenzene	19.04	0.984	0.11	0.24	^†	^†	0.13	^†	^†	0.17
Hexanal	17.5	0.995	0.11	0.28	0.45	0.62	0.91	0.49	0.62	0.81
Nonanal	25.32	0.954	0.40	0.91	1.44	2.02	3.09	1.51	2.27	3.12
Styrene	20.18	0.982	0.02	0.03	0.05	0.09	0.24	0.03	0.06	0.21
b) feces					57 measurements			50 measurements
Pentane^*	13.22	0.999	2.41	11.1	13.5	18.1	23.1	11.8	16.6	21.1
Hexane^*	20.58	0.999	4.41	16.3	1.9	10	12.4	^†	^†	9.4
Heptane^*	23.83	0.998	2.64	8.81	7.4	8.9	12.1	6	8.2	10
Acetone^*	10.11	0.999	7.06	24.8	613	857	1180	273	379	476
2-Butanone	16.06	1.000	0.43	1.26	53	100	169	46	78	107
2-Pentanone	22.13	0.998	1.69	5.64	278	416	586	192	276	339
2-Hexanone	24.97	0.997	5.39	18.0	117	174	224	59	95	120
2-Heptanone^*	26.46	0.999	2.98	9.94	27.4	36.9	46.3	21.5	26	34.2
3-Octanone^*	28.36	0.999	22.6	75.5	41.1	58.3	90.6	25.3	51	86.1
2-Butanone, 3-methyl-	21.53	0.997	0.53	1.77	23.8	28.5	36.4	29.1	39.4	72.7
2-Pentatone, 3-methyl-	24.22	0.997	1.79	5.95	24.1	34.1	63.9	13.4	17.9	27.5
Methyl Isobutyl Ketone^*	24.00	0.998	1.26	4.19	9.7	13.2	16.9	6	7.8	10.9
Isoprene^*	12.63	1.000	1.22	4.65	20	27.2	35.1	4.2	12.5	22.1
Acetic acid, methyl ester^*	11.57	0.999	0.29	0.97	42.5	49.6	61.4	45.6	57.1	72.3
Sulfide, dimethyl	10.91	0.997	0.99	3.29	473	869	1316	99	183	360
Disulfide, dimethyl^*	22.61	0.993	0.08	0.26	0.5	2	6.5	^†	0.4	1.1
Furan^*	9.81	0.999	0.10	0.35	1.5	1.8	2.3	1.6	1.9	2.8
Furan, 2-ethyl-^*	21.95	0.998	0.19	0.65	8.3	10.1	12.4	4.6	6.1	7.7
Furan, 2-methyl-^*	15.82	0.993	9.6	31.8	16.4	20.3	27.6	11.9	14.9	17.2
Furan, 3-methyl-^*	16.62	0.996	0.13	0.42	24.1	31.8	40.1	17.3	21	25.6
Furan, 2-pentyl-^*	28.40	0.995	4.64	15.5	23.6	28.2	34.5	19.3	24.6	33.2

R²—coefficient of determination;LOD—limit of detection;LOQ—limit of quantification

* potential marker substances from a former in vitro study [9]

^† values lower than LOD