LCK Reagent Set measures chemical oxygen demand in water and wastewater.
13 mm LCK Cuvette test measures COD in the range of 0-1000 mg/L O₂ in water and wastewater. The product uses dichromate method (ISO 15705). Article LCI400 can be used for 24 tests (each package contains one blank test). LCK product can be evaluated on DR3900, DR6000, DR1900, DR2800, DR3800 and DR5000.
Before you start take into account the following:
- Water samples (including diluted samples) with concentrations of chloride up to 1000 mg/L may be used for this method.
- Water samples require digestion and must be heated in the preheated thermostat at 148 °C (298.4 °F) for 2 hours.
Summary of method
Oxidizable substances are reacting with sulfuric acid and potassium dichromate solution. Silver sulfate serves in the aforementioned reaction as catalyst. Mercury sulfate is masking chloride. The green color of Cr3+ must be evaluated with one of the aforementioned instruments.
Sample preparation
For short-term conservation of the water sample (up to 24 hours) the suggested temperature is between +2 °C and +5 °C. The longer-term conservation (up to 14 days) temperature should be around -18 °C. The sample must be carried in glass or polyethylene vessel. Article LCI400 storage conditions are between 15 °C and 25 °C protected from light.
Brand | Hach |
Parameter | COD |
Measuring range | 0-1000 mg/L O₂ |
Instrument | DR3900, DR6000, DR1900, DR2800, DR3800 and DR5000 |
Method | Dichromate method |
Standard method | ISO 15705 |
Digestion required | Yes |
Number of tests | 24 tests, one blank test |
Storage conditions | 15 °C - 25 °C (protected from light) |