Table 2.

The characteristics of the 12 discriminatory biomarkers from the statistical analyses.

Retention time (min)	Compound name	Chemical formula	NIST match (%)	Retention index (RI) value		RSD (%)	VIP score	t-test		SAM
				Reference	Experiment			p-value	FDR	q-value
4.42	hexanala	C6H12O	91	806	799	21.449	1.743	<0.001	0.005	0.005
5.95	1-hexanola	C6H14O	92	860	859	28.631	1.926	<0.001	0.005	0.005
10.31	decane, 4-methyla	C11H24	95	1051	1031	25.630	1.665	<0.001	0.009	0.013
10.58	nonane, 2,2,3-trimethyl	C12H26	92	1065	1039	13.765	1.852	<0.001	0.007	0.021
11.24	decane, 3,4-dimethyl	C12H26	91	1086	1069	12.606	2.106	<0.001	0.005	0.005
12.01	1-decene, 2,4-dimethyl	C12H24	90	1117	1084	7.748	1.978	<0.001	0.005	0.005
12.32	decane, 2,3,4-trimethyl	C13H28	90	1121	1098	11.944	2.061	<0.001	0.005	0.005
12.58	1-undecene, 4-methyl	C12H24	90	1140	1121	29.447	1.771	<0.001	0.006	0.007
17.43	dodecane, 4-methyla	C13H28	90	1249	1240	17.141	2.226	<0.001	0.005	0.004
18.25	tridecane, 7-methyla	C14H30	93	1349	1320	21.504	1.018	<0.001	0.010	0.023
20.40	tridecane, 4,8-dimethyl	C15H32	90	1384	1373	20.486	1.799	<0.001	0.005	0.005
24.55	hexadecane, 7,9-dimethyl	C18H38	93	1683	1642	23.236	1.005	<0.001	0.010	0.077

^aConfirmed by standard.