Table 1.

Molecular weight, mass peak (m/z), retention time (RT), calculated Kovats indicies (CKI) and tabulated Kovats retention indices (TKI) of the volatile compounds identified from intact tomato plants after four nitrogen treatments (see Figure 6 for relative amounts of volatile organic compounds indicated by peak areas found from different levels of nitrogen-treated tomato plants).

Peak no	Compounds	Chemical class	Molecular weight	Mass peak (m/z)	RT (min)	CKI	TKI	Reference
1	Heptanal	Alkyl aldehyde	114	70, 44, 41, 55	6.95	903	901	Babushok and Zenkevich, 2008
2	α-Pinene	Monoterpene	136	93, 91, 92, 77	7.65	932	932	Adams, 2009
3	β-Pinene	Monoterpene	136	93, 41, 69, 91	8.58	970	973	Franco et al., 2011
4	Myrcene	Monoterpene	136	41, 93, 69, 53	9.14	993	990	Adams, 2009
5	(+)-4-carene	Monoterpene	136	93, 121, 136, 91	9.30	1000	1001	Le Quere and Latrasse, 1990
6	α-Terpinene	Monoterpene	136	93, 121, 91, 136	9.69	1018	1019	Franco et al., 2011
7	p-Cymene	Monoterpene	134	119, 134, 91, 120	9.86	1025	1023	Franco et al., 2011
8	β-Phellandrene	Monoterpene	136	93, 77, 91, 136	9.94	1029	1029	Franco et al., 2011
9	Nonanal	Alkyl aldehyde	142	57, 41, 43, 56	11.63	1108	1108	Engel et al., 2002
10	δ-Elemene	Sesquiterpene	204	121, 93, 41, 107	15.96	1343	1338	Adams, 2009
11	α-Copaene	Sesquiterpene	204	161, 119, 105, 93	16.61	1382	1376	Franco et al., 2011
12	Longifolene	Sesquiterpene	204	161, 94, 91, 93	17.12	1413	1416	Hognadottir and Rouseff, 2003
13	α-Cedrene	Sesquiterpene	204	119, 93, 105, 204	17.23	1420	1419	Da Cruz et al., 2014
14	β-Caryophyllene	Sesquiterpene	204	93, 133, 91, 41	17.34	1427	1425	Da Cruz et al., 2014
15	α-Humulene	Sesquiterpene	204	93, 80, 41, 121	17.88	1462	1460	Da Cruz et al., 2014
16	Farnesan	Alkane	212	57, 71, 43, 41	20.01	1604	–	–