221.5 mg/L = 221.5 ppm
| mg/L | ppm |
|---|---|
| 206.5 mg/L | 206.5 |
| 211.5 mg/L | 211.5 |
| 216.5 mg/L | 216.5 |
| 221.5 | 221.5 |
| 226.5 mg/L | 226.5 |
| 231.5 mg/L | 231.5 |
| 236.5 mg/L | 236.5 |
221.5 mg/L = 221.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm