LCK914 COD Cuvette Test, 5-60 g/L O₂

LCK Cuvette test measures COD in the range of 5-60 g/L O₂ in wastewater. The product uses dichromate method (ISO 6060-1989, DIN 38409-H41-H44). 13 mm LCK Reagent Set can be used for 25 tests. Article LCK914 can be evaluated using following spectrophotometers: DR3900, DR6000, DR1900, DR2800, DR3800 and DR5000.

Before you start take into account the following:

• Wastewater samples (including diluted samples) with maximum chloride concentrations of 1000 mg/L may be used for this method.
• Analysis results must additionally be examined for plausibility.

Procedure for O₂ evaluation

Samples of wastewater must be added in the stirred cuvette and should be heated in the classic heating block at 148 °C (298.4 °F) for 2 hours or in the high temperature thermoreactor for 15 minutes.

Summary of method

Oxidizable substances enter into a reaction with sulphuric acid and potassium dichromate solution in the presence of silver sulphate as reaction catalyst. Chloride is masked by mercury sulphate. Cr3+ green coloration should be evaluated with one of the abovementioned spectrophotometers.

Sample preparation

The wastewater sample may be stored for up to 24 hours at the temperature between +2 °C and +5 °C and for up to 14 days at the temperature of -18 °C. The water sample should be carried in glass or polyethylene vessel. Cuvette test LCK914 must be stored at the temperature between 15 °C and 25 °C protected from the light.