Description
Standard potassium iodide-iodate titrant standardized to 0.0125N
Titrate with potassium iodide-iodate titrant until end point and faint permanent blue color develops.
Calculation of Results
FORMULA: ppm sulfite as SO3 = ml of potassium iodide-iodate (RXSOL-62-5503-006) x 500 / ml SAMPLE
Using a 50 ml sample, sulfite, in parts per million as SO3 is equal to the ml of RXSOL-62-5503-006 required multiplied by 10.
Example:
A 50-mL sample was titrated with 0.0125 N titrant and 6 mL of titrant was used at the endpoint. The concentration is 6 mL × 10 = 60 mg/L sulfite SO3 2–
Sample volumes and multipliers
| Range (mg/L) | Sample volume (mL) | Titrant—potassium iodide-iodate | Multiplier |
| 0–100 | 50 | 0.0125 N | 10 |
| 40–200 | 25 | 0.0125 N | 20 |
| 100–500 | 10 | 0.0125 N | 50 |
| More than 500 | 05 | 0.0125 N | 100 |