The method describes how to determine the total chlorine content of water using an iodometric method.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
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Free chlorine: |
Chlorine present as hypochlorous acid, hypochlorite ions or as dissolved elemental chlorine. |
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Bound chlorine: |
Percentage of total chlorine present in the form of chloramines and organic chloramines. |
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Total chlorine: |
Chlorine present as “free chlorine” and “bound chlorine”. |
The total chlorine reacts with potassium iodide in an acidic solution, releasing free iodine. Immediate reduction of the iodine is performed using a thiosulfate standard solution, of which a known amount in excess of that required was added to the solution in advance. The thiosulfate left untransformed is titrated using a potassium iodate standard reference solution to complete the analysis.