microtest® Test Kit Specifications

microtest Dissolved Oxygen

Titrimetric Test for

Dissolved Oxygen

1 drop = 0.5 mg/L O2

Product Code608000
ContentsReagent A, 8 mL
Reagent B, 8 mL
Reagent C, 15 mL
Indicator, 10 mL
Titration Solution, 15 mL
Test Tube, 10 mL
Water Sampling Flask with Stopper, all glass, 25 mL
Instructions for Use
Analytical MethodModified Winkler Method: In strongly alkaline conditions, dissolved oxygen oxidises manganese ions Mn2+ to insoluble Mn(IV) oxide hydrates. On dissolution of these oxide hydrates with sulphuric acid, they in turn oxidise iodide ions to form free iodine. By that process every atom of dissolved oxygen produces two atoms of iodine. Finally the iodine is titrated with thiosulphate against a starch indicator.
Number of Tests30 – 50
InterferencesOxidising and reducing agents. Ferrous iron >1 mg/L. Nitrite will not interfere.
Measuring RangeThe recommended measuring range is 1 to 10 mg/L (1 - 20 drops @ 0.5 mg/L) for 5 mL of sample volume. This range can be extended by taking a smaller sample for the titration. For a 2.5 mL sample the measuring range is 2 to 20 mg/L.
Shelf Life2 years
ApplicationsDetermination of dissolved oxygen (DO) levels in dams, creeks and rivers (environmental monitoring), in industrial water treatment (boiler feed water) and in aquaculture.