Oxygen determination according to Winkler: in alkaline solution dissolved oxygen oxidises manganese(II) ions to higher-valent manganese hydroxides. In a strongly acidic medium these form manganese(III) ions which can be determined either titrimetrically or colorimetrically after addition of a colour reagent.

The solubility of oxygen in water depends on the temperature, the pressure and the other components of the water. The oxygen content of a water at the time of sampling is often quoted as the percentage of the possible saturation.

Please note:
When ordering this test kit for the first time, you also need an oxygen bottle, REF 915 498.