Ambient measurements of 2,2,4-trimethyl, 1,3-pentanediol monoisobutyrate in Southern California

Figures & data

Figure 1. Isomers of TPM.

Figure 2. Map of Southern California with sampling locations circled, as well as the location of downtown Los Angeles.

Figure 3. Typical ambient air chromatogram with reference TPM chromatogram superimposed.

Figure 4. Calibration curve for TPM analyzed by GC-FID.

Table 1. Mean concentrations of TPM for each season in each city

			Isomer 1 (ppt)		Isomer 2 (ppt)
City	Season	Time of Day	Mean	Range	Mean	Range
Azusa	Summer	Morning	15.9	5.0–22.2	24.1	10.0–33.9
	Fall	Morning	6.0	2.3–8.9	11.5	4.5–19.0
	Winter	Morning	4.9	1.3–10.5	8.9	2.1–16.7
	Spring	Morning	6.1	1.8–11.1	11.6	4.9–19.3
	Summer	Afternoon	9.2	3.7–15.7	13.0	8.1–21.8
	Fall	Afternoon	6.4	2.1–11.8	11.7	4.1–19.4
	Winter	Afternoon	6.8	1.3–17.9	16.6	2.9–49.6
	Spring	Afternoon	5.3	1.9–8.5	10.7	6.3–14.7
Pico Rivera	Summer	Morning	13.7	4.4–26.9	19.9	7.8–40.9
	Fall	Morning	8.1	4.7–11.6	15.3	9.6–19.6
	Winter	Morning	7.3	2.9–10.6	14.5	5.6–23.4
	Spring	Morning	9.3	7.3–11.7	15.8	11.8–19.3
	Summer	Afternoon	5.3	3.9–6.8	7.3	6.1–8.4
	Fall	Afternoon	8.1	6.2–10.0	14.1	9.5–19.2
	Winter	Afternoon	8.5	2.6–13.8	17.8	6.9–32.9
	Spring	Afternoon	8.2	6.6–9.7	14.0	10.6–17.9
Riverside	Summer	Morning	11.7	7.0–15.7	17.8	8.9–22.6
	Fall	Morning	11.4	1.0–27.3	20.9	1.4–49.5
	Winter	Morning	5.1	1.7–10.8	10.7	4.0–19.8
	Spring	Morning	7.5	2.7–12.9	16.1	8.4–27.4
	Summer	Afternoon	5.0	3.5–7.6	7.8	6.5–12.6
	Fall	Afternoon	9.1	0.7–17.7	18.2	1.7–41.8
	Winter	Afternoon	6.5	0.8–13.7	10.4	1.6–24.0
	Spring	Afternoon	5.7	2.2–10.7	11.9	6.1–23.0

Figure 5. Time-series data for each city for isomer 1. Morning hours in dark gray, afternoon hours in light gray. (a) Azusa, CA; (b) Pico Rivera, CA; (c) Riverside, CA.

Figure 6. Plots of isomer 2 versus isomer 1 for each city. (a) Azusa, CA; (b) Pico Rivera, CA; (c) Riverside, CA.