Permanganate index

Detection of oxidization by potassium permanganate (permanganate index) in an acid medium under hot conditions.

The principle of the method specified is heating a sample in a boiling water-bath with a known amount of potassium permanganate and sulphuric acid for a fixed period time (10 min), reducing part of the permanganate by oxidizable material in the sample and determining the consumed permanganate by addition of an excess of oxalate solution, followed by titration with permanganate. Applies to waters having a cloride ion concentration of less than 300 mg/l. Samples having a permanganate index over 10 mg/l should be diluted before analysis. The lower limit of the optimum range of the test is 0.5 mg/l.

The Permanganate Index method is not recommended for waste water due to the fact that some organic compounds are not oxidized or incompletely.

See also

• Permanganate