Table 1. Summary of major N-SOA components measured by TD-GC/MS.

No.	Name	Structure	Molecular Weight (g/mol)	Retention Time (min)	Retention Indexa (measured)	Retention Indexb (literature)	MS Matchc	MS Reverse Matchc
1	Benzoic acid		122.12	7.37	1167	1170	894	913
2	Phthalic acid		166.14	9.19	1299	n.a.d	977	976
3	1-Isobenzofuranone		134.13	9.64	1333	n.a.	903	935
4	1,3-Indandione		146.14	9.79	1344	1358	890	931
5	1,4-Naphthoquinone		158.15	10.54	1402	1404	839	883
6	1,5-Naphthalenediol		160.17	11.38	1469	n.a.	832	833
7	2-Acetylbenzoic acid		164.16	11.55	1483	n.a.	921	937
8	1-Naphthalenol		144.17	11.82	1505	1525	877	883
9	2-Naphthalenol		144.17	11.98	1518	1536	914	915
10	2-Hydroxy-1,4-naphthoquinone		174.15	12.20	1537	n.a.	887	903
11	2-Formyl-cinnamaldehyde		160.17	13.70	1666	n.a.	n.a	n.a
12	2,3-Naphthalenediol		160.17	15.13	1799	n.a.	913	920
13	(3-Oxo-1,3-dihydro-2-benzofuran-1-yl)acetic acid		192.17	15.51	1836	n.a.	883	889

Compounds were identified by comparing measured retention indices to literature values, and/or by mass spectral matching. N-SOA composition revealed in this study is consistent with that measured previously²⁷.

^aRetention index was calibrated using n-alkane standard. Calculation of retention indices is illustrated in detail in Supporting Information.

^bReference literature for the retention indices of listed components can be found in Supporting Information.

^cThe fragmentation mass spectral patterns for SOA components were compared to the NIST EI-MS Library. Only peaks with Match and Reverse Match factors greater than 800 are listed.

^dn.a. indicates that retention index is not available in the literature.