This application note provides a complete solution to determine Permanganate Index (PI) in water using METTLER TOLEDO's titrator automated with an InMotion™ Autosampler.
What Is Permanganate Index?
Permanganate index in water is a parameter to characterize the quality of potable and raw water in water utilities and water control laboratories. PI is expressed as mg oxygen/L i.e mg O/L. This method is limited to water samples containing less than 500 mg/L chloride. Higher chloride concentrations lead to erroneous results due to the oxidation of chloride ions. Hence, this method is suitable for drinkable waters only.
Method of Analysis
The permanganate index of water is determined by the back titration method using a standard oxalate solution. The blank and titer values are determined in deionized water using two equivalence point (EQP) titration method functions.
Procedure
- The water sample is heated along with the potassium permanganate solution for a defined time. During this step, the water molecule reduces potassium permanganate.
- Then the unreduced permanganate solution is allowed to react with the sodium oxalate solution which is added in excess concentration.
- The unreacted sodium oxalate concentration is determined by titrating it against the permanganate solution.
This Application Note Includes
- Sample preparation and procedures
- Solutions and chemicals
- Chemistry
- Instruments and accessories
- Method in detail
- Results and remarks
And method files (.lmt and .xml) for direct import and implementation on the instrument.
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