Table 4.

Compounds (N = 30) associated with at least one traffic related air pollutant in the TAPAS II study (sorted on mass to charge ratio).

Identity	m/z (Da)	Retention time (min)	m/z difference (ppm)	Identification levela	Direction	Associated pollutant
Unknown	175.1114	6.17		4	Up	PM2.5, PM10
l-Tyrosine	182.0812	1.34	0.1	1	Up	PMcoarse, PM10
Unknown	229.1171	2.48		4	Up	PM2.5, PM10
Unknown	233.1158	5.07		4	Up	NOx
Unknown	239.162	5.72		4	Up	PM2.5, NOx
Unknown	263.1392	3.13		4	Up	PMcoarse, PM2.5, PM10
Unknown	267.1329	1.87		4	Up	PMcoarse
Unknown	271.0866	5.72		4	Up	NOx
Unknown	283.2419	6.8		4	Up	PMcoarse
Unknown	302.1961	2.13		4	Up	PMcoarse
Unknown	302.1963	1.86		4	Up	PMcoarse, PM10
Unknown	309.2281	4.98		4	Up	PM10
Unknown	319.224	6.67		4	Up	PM2.5, NOx
Unknown	346.1044	1.36		4	Up	PM10
Unknown	351.1547	4.65		4	Up	PM2.5, PM10
Unknown	362.0995	1.35		4	Up	PMcoarse, PM10
Unknown	367.1935	4.81		4	Up	PM2.5
Unknown	367.3287	7.7		4	Up	PMcoarse, PM10
Unknown	387.1958	6.17		4	Up	PMcoarse, PM10
Unknown	397.1992	6.72		4	Up	PMcoarse
Unknown	421.251	6.79		4	Up	PMcoarse, PM2.5, PM10
Unknown	453.2453	2.69		4	Up	PMcoarse, PM10
Unknown	471.7381	3.8		4	Up	NOx
PC (16:0)	502.3284	7.14	−3.1	3	Up	PM2.5, PM10
PC (20:2)	570.3553	7.16	0.2	3	Up	PM2.5
Unknown	575.4643	7.69		4	Up	PM10
Unknown	581.4497	8.13		4	Up	PMcoarse, PM10
Unknown	612.5152	7.54		4	Up	PMcoarse, PM2.5, PM10
Unknown	617.4728	7.5		4	Up	PMcoarse, PM2.5, PM10
Unknown	784.527	7.79		4	Up	PMcoarse, PM10

Level 1 (identity confirmed): retention time and MS/MS matched with an authentic chemical standard; Level 3 (putatively characterized compound classes): no standard available or analyzed but mass within 5 ppm mass error and MS/MS spectra matches with those in a database.

^aIdentification level as defined by Sumner et al. (2007).