LCK514 COD Cuvette Test, 100-2000 mg/L O₂

13 mm LCK Cuvette test measures COD in the range of 100-2000 mg/L O₂ in wastewater. The product uses dichromate method (ISO 6060-1989, DIN 38409-H41-H44). Article LCK514 may be used to test 25 samples. LCK product can be analyzed with spectrophotometers DR3900, DR6000, DR1900, DR2800, DR3800 and DR5000.

Before starting analysis:

• Wastewater samples (including diluted samples) with concentrations of chloride up to 1500 mg/L may be used for this method.
• Testing results of the conducted measurement should be checked for plausibility.

Procedure for O₂ measurement

Cuvette should be inverted a several times to bring the sediment into suspension, pipet approximately 2.0 mL of the wastewater sample into cuvette and heat the cuvette for 2 hours at 148 °C in the classic thermostat or 15 minutes in the high temperature thermostat.

Summary of method

Oxidizable substances react with sulphuric acid and potassium dichromate solution in the presence of silver sulphate that is the catalyst in the aforementioned reaction. Mercury sulphate masks chloride. The green color of Cr3+ is estimated.

Sample preparation

For short-term conservation (up to 24 hours) the wastewater sample should be kept at the temperature between +2 °C and +5 °C and for long-term conservation (up to 14 days) at around -18 °C. The sample must be carried in glass or polyethylene vessel. LCK514 storage conditions are between 15 °C and 25 °C protected from light.