Table 1.

Sesquiterpenes and terpenoids observed in the gas phase during GoAmazon2014/5 with proposed identification and their alkane-based retention index, Chemical Abstracts Service (CAS) number, mean concentration during wet and dry seasons, reaction rate constant with O₃ (ko₃), and estimated chemical lifetime in the presence of 20ppb_v O₃. ko₃ is estimated using EPA EPI Suite 4.1 AOPWIN where literature data are unavailable. Concentrations of each species are estimated by using an average instrument response factor for several sesquiterpene standards unless otherwise noted that an authentic standard was used. Other commonly studied sesquiterpenes typically below detection or unobserved are also included for comparison of reactive timescales.

No.	Compound	Retention index	CAS no.	Wet season mean concentration		Dry season mean concentration		kO3 × 1017 (cm3 molec−1	τ for [O3] = 20 ppbv (min)
				(ngm −3)	(ppqv)	(ng m −3)	(ppqv)
Sesquiterpenes
1	α-cubebene	1355	17699–14-8	2.25	250	1.90	211	43.0	78.9
2	unidentified	1380		2.86	318	1.12	125
3	cyclosativene	1383	22469–52-9	2.86	317	1.16	129	7.4	458.7
4	α-copaene	1387	3856–25-5	3.75a	417	3.92a	435	16b	212.0
5	β-elemene	1397	515–13-9	2.08	231	1.46	163	2.6	1317.2
6	cyperene	1420	2387–78-2	1.61	179	0.81	90	NEc
7	α-cedrene	1435	469–61-4	0.25a	28	0.45a	49		78.9
8	unidentified	1443		4.76	529	6.04	670		2.8b
9	β-gurjunene	1447	17334–55-3	0.88	97	0.88	98	7.4	458.7
10	unidentified	1453	26620–71-3	0.32	35	0.01	2
11	unidentified	1462		1.61	179	1.38	153
12	α-patchoulene	1471	560–32-7	0.27	30	1.01	113	7.4	458.7
13	unidentified; SQT202	1474		0.29	33	0.43	49
14	(−) alloaromadendrenea	1476	025246–27-9	1.93a	214	1.72a	191	1.2	2826.4
15	γ-muurolene	1486	30021–74-0	0.18	20	0.11	12	44.2	76.7
16	unidentified; SQT202	1486		2.36	265	4.89	548
17	α-amorphene	1490	20085–19-2	1.23	136	1.03	114	86.0	39.4
18	β-selinene	1505	17066–67-0	0.45	50	2.38	264	2.4	1413.2
19	α-muurolene	1509	31983–22-9	1.50	166	1.45	161	86.0	39.4
20	unidentified	1512		2.14	237	1.50	167
21	β-bisabolene	1513	495–61-4	1.24	138	0.32	36	87.20	38.9
22	cuparene	1524	16982–00-6	1.13	127	0.62	69
23	γ -cadinene	1526	39029–41-9	1.75	194	1.18	131	44.2	76.7
24	δ-cadinene	1529	483–76-1	0.95	105	0.81	90	163.0	20.8
25	cis-calamenene SQT202	1534	72937–55-4	0.81	91	0.32	35	NEc
26	selinene < 7-epi-α >	1537	6813–21-4	0.14	15	0.22	25	163.0	20.8
27	γ -cuprenene	1545	4895–23-2	0.32	35	0.14	15	50.4	67.3
28	α-cadinene	1549	24406–05-1	0.17	18	0.06	7	86.0	39.4
29	unidentified	1553		0.01	1	0.13	14
30	selina-3,7(11)-diene	1558	6813–21-4	0.07	8	0.10	11	163.0	20.8
Below detection or unobserved
	β-caryophyllene	1427	87–44-5	n/a	n/a	n/a	n/a	1160.0	2.9
	trans-α-bergamotene	1442	13474–59-4	n/a	n/a	n/a	n/a	86.0	39.4
	aromadendrene	1450	489–39-4	n/a	n/a	n/a	n/a	1.2	2826.4
	α-humulene	1471	6753–98-6	n/a	n/a	n/a	n/a	1170.0	2.9
	β-farnesene		18794–84-8	n/a	n/a	n/a	n/a	40.1d	84.6
	α-farnesene	1509	502–61-4	n/a	n/a	n/a	n/a	104.0	32.6
	valencene	1523	4630–07-3	n/a	n/a	n/a	n/a	8.6	394.7
Diterpenes
31	rimuene	1958	1686–67-5	0.21	18	0.22	19	7.6	448.1
32	pimaradiene	1977	1686–61-9	0.11	10	0.14	12	7.6	448.1
33	Sandaracopimaradiene	1995	1686–56-2	0.38	33	0.15	13	7.6	448.1
34	kaurene	2085	34424–57-2	0.97	86	0.69	60	1.1	2981.7
	Total sesquiterpenes + diterpenes:			41.8	4611	38.8	4285	n/a	n/a

^aAuthentic standard used for quantification.

^bShu and Atkinson (1994).

^cNE: no estimate in EPI Suite.

^dKourtchev et al. (2009).