Table 2. Experimental Conditionsa.
expt # | date | BVOC | [BVOC]I (ppb) | [N2O5]I (ppb) | kNO3+BVOC @298 K (cm3 molec-1 s–-1) | [N2O5]i/[BVOC]i |
---|---|---|---|---|---|---|
1 | 9/15/11 | α-pinene (seeded) | 48 | 54 | 6.16 × 10–12 | 1.1 |
2 | 9/28/11 | β-pinene “high” | 41 | 60 | 2.51 × 10–12 | 1.5 |
3 | 10/18/11 | β-pinene “low” | 10 | 10 | 2.51 × 10–12 | 1.0 |
4 | 9/19/11 | Δ-3-carene “high” | 16 | 42 | 9.1 × 10–12 | 2.6 |
5 | 10/21/11 | Δ-3-carene “low” | 10 | 9 | 9.1 × 10–12 | 0.9 |
6 | 10/3/11 | limonene “high” | 40 | 60 | 1.22 × 10–11 | 1.5 |
7 | 10/11/11 | limonene “low” | 10 | 10 | 1.22 × 10–11 | 1.0 |
8 | 10/15/11 | limonene (+ O3 + NO2) | 10 | [O3]i = 12 ppb; [NO2]i= 6.3 ppb | 1.22 × 10–11 | 1.2 |
9 | 9/22/11 | β-caryophyllene “high” | 109 | 40 | 1.9 × 10–11 | 0.4 |
10 | 10/26/11 | β-caryophyllene “low” | 3 | 10 | 1.9 × 10–11 | 3.0 |
11 | 11/11/11 | sabinene | 9 | 10 | 1 × 10–11 | 1.1 |
Except α-pinene, all experiments were conducted without seed aerosol. Rate constants at 298 K are taken from Calvert et al. (2000).21 For the “low” experiments, the ratio of N2O5 to BVOC in the inlet line was approximately 1:1; for the “high” experiments, the oxidant was generally in slight excess (with the exception of Expt # 9). The highest purity sabinene source available was 80%, and contained 20% β-pinene. No correction was applied for this, so sabinene SOA reflects this mixture.