Potassium Iodide-Iodate Titrant
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.
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|
|More than 500||05||0.0125 N||
Dissolve 445.8 mg anhydrous potassium iodate, KIO3 (primary standard grade dried for several hours at 120°C), 4.25 g KI and 310 mg NaHCO3 in distilled water and dilute to 1 liter.