Table 3.

Oxidation products from isoprene (ISOPOX) and monoterpenes (MTOXs) in central Amazonia in gas and/or particle phases. Only particle-phase measurement is presented in this study. Products marked not applicable (n/a) are not detected in the UHRMS analysis method.

No.	Tracer name	Source category	Analysis methods	Chemical formula	Molecular weight (g mol−1)	UHRMS measured m/z m/z [M-1]−	UHRMS average % of total signal intensity
1	2-MT 1 or 2-methylerythritol	ISOPOX	SV-TAG; filter GC × GC	C5H12O4	136.15	n/a	n/a
2	2-MT 2 or 2-methylthreitol	ISOPOX	SV-TAG; filter GC × GC	C5H12O4	136.15	n/a	n/a
3	C5-alktriol 1 or 3-methyl-2,3,4-trihydroxy-1-butene	ISOPOX	SV-TAG; filter GC × GC	C5H10O3	118.13	n/a	n/a
4	C5-alktriol 2 or cis-2-methyl- 1,3,4-trihydroxy-1-butene	ISOPOX	SV-TAG; filter GC × GC	C5H10O3	118.13	n/a	n/a
5	2-MGA or 2-methylglyceric acid	ISOPOX	SV-TAG; filter GC × GC	C4H8O4	120.10	n/a	n/a
6	DTAA or diaterpenylic acid acetate	MTOX	Filter UHPLC-MS; filter ESI-UHRMS	C10H16O6	232.23	231.08728	0.57
7	MBTCA or 3-methyl-1,2,3-butanetricarboxylic acid	MTOX	Filter GC × GC HR-ToF-	C8H12O6	204.18	203.05606	0.87
8	pinic acid	MTOX	filter ESI-UHRMS Filter GC × GC HR-ToF-	C9H14O4	186.21	185.08186	0.96
9	pinonic acid	MTOX	filter ESI-UHRMS Filter UHPLC-MS; filter ESI-UHRMS	C10H16O3	184.23	183.10259	2.73
10	terpenylic acid	MTOX	Filter UHPLC-MS; filter	C8H12O4	172.18	171.06618	0.78
11	cis-norpinic acid	MTOX	ESI-UHRMS Filter GC × GC HR-ToF-	C9H16O3	172.22	171.10252	2.97