421.5 mg/L = 421.5 ppm
| mg/L | ppm |
|---|---|
| 406.5 mg/L | 406.5 |
| 411.5 mg/L | 411.5 |
| 416.5 mg/L | 416.5 |
| 421.5 | 421.5 |
| 426.5 mg/L | 426.5 |
| 431.5 mg/L | 431.5 |
| 436.5 mg/L | 436.5 |
421.5 mg/L = 421.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm