LCK238 Laton Total Nitrogen Cuvette Test, 5-40 mg/L TNb

LCK Cuvette test measures 5-40 mg/L TNb in water and wastewater. The product uses Koroleff digestion and photometric detection method (EN ISO 11905-1). Article LCK238 can be used for 25 tests. LCK product can be evaluated on DR3900, DR6000, DR1900, DR2800, DR3800 and DR5000.

Procedure for TNb measurement

Pour 0.5 mL sample, 2.0 mL solution A and 1 tablet B into the reaction tube and heat at the recommended temperature either using the classic thermostat or high temperature thermoreactor (required temperatures may be found in the manual). Cool down and invert the reaction tube a few times. Afterwards pipet 0.5 mL of digested sample and 0.2 mL of solution D into the cuvette. Close and invert the cuvette a few times before testing it using one of the aforementioned instruments.

Summary of method

Inorganically and organically bonded nitrogen is oxidized to nitrate by digestion with peroxo-disulphate. The nitrate ions react with 2.6-dimethylphenol in a solution of sulphuric and phosphoric acid to form a nitrophenol. Pink color that may occur during the reaction will not interfere with the analysis.

Sample preparation

For short-term conservation of up to 1 week the water pH is required to be 3-7 pH. For long-term water and wastewater conservation of up to 14 days the recommended temperature is -18 °C. The sample should be stored in glass, polyethylene or borosilicate glass container. The product storage temperature must be between 15 °C and 25 °C.