Table 1. Statistical parameters of stable isotopes (δ34Ssulfate and δ18Osulfate) and water-soluble ions in Beijing aerosols (SD represents standard deviation).
| Species | Spring | Summer | Autumn | Winter | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Range | Average | SD | Range | Average | SD | Range | Average | SD | Range | Average | SD | |
| Na+(μg/m3) | 0.4–1.8 | 1.1 | 0.5 | 0.1–1.0 | 0.5 | 0.2 | 0.2–2.1 | 1.1 | 0.6 | 0.7–4.4 | 2.0 | 1.1 |
| NH4+(μg/m3) | 0.6–38.5 | 9.9 | 12.6 | 0.3–25.3 | 7.4 | 7.0 | 1.8–14.0 | 7.5 | 3.7 | 1.4–23.8 | 8.8 | 5.9 |
| K+(μg/m3) | 0.4–3.6 | 1.6 | 1.1 | 0.2–2.8 | 1.0 | 0.6 | 0.7–3.8 | 1.8 | 0.8 | 0.4–3.9 | 1.6 | 1.0 |
| Mg2+(μg/m3) | 0.2–1.9 | 0.8 | 0.5 | 0.1–1.6 | 0.8 | 0.4 | 0.3–1.5 | 0.9 | 0.4 | 0.1–1.2 | 0.5 | 0.3 |
| Ca2+(μg/m3) | 4.7–24.9 | 11.3 | 6.9 | 3.1–10.7 | 6.8 | 2.3 | 3.4–14.8 | 9.8 | 3.7 | 1.5–13.8 | 6.2 | 3.1 |
| F−(μg/m3) | 0.1–2.1 | 0.7 | 0.6 | 0.0–0.5 | 0.3 | 0.2 | 0.3–1.3 | 0.6 | 0.3 | 0.1–1.0 | 0.5 | 0.3 |
| Cl−(μg/m3) | 0.6–6.6 | 2.8 | 1.7 | 0.2–3.8 | 1.0 | 0.8 | 0.3–11.1 | 4.3 | 3.1 | 1.7–12.4 | 6.5 | 3.5 |
| NO3−(μg/m3) | 2.3–89.8 | 30.7 | 32.7 | 2.5–54.6 | 19.6 | 13.9 | 9.3–43.4 | 25.7 | 12.2 | 2.7–46.3 | 16.3 | 12.6 |
| SO42−(μg/m3) | 3.7–87.7 | 25.2 | 31.3 | 2.4–85.7 | 22.1 | 18.5 | 4.3–34.7 | 16.6 | 8.2 | 4.0–60.7 | 17.4 | 13.5 |
| δ34Ssulfate | 4.5–9.2 | 6.4 | 1.5 | 3.4–7.0 | 5.0 | 0.9 | 5.0–9.4 | 6.8 | 1.3 | 7.1–11.3 | 8.6 | 0.9 |
| δ18Osulfate | 7.2–12.5 | 10.6 | 1.7 | 3.8–12.3 | 9.3 | 2.1 | 8.2–12.6 | 11.1 | 1.3 | 11.3–16.1 | 13.4 | 1.4 |