2608345 Nitrite Cuvette Test, 0.002-0.500 mg/L NO₂-N

16 mm Test 'N Tube Cuvette test measures 0.002-0.500 mg/L NO₂-N in water, wastewater and seawater. The product uses diazotization method (10019). Article 2608345 can be used for 50 tests. The product is compatible with DR900 only.

Procedure for NO₂-N determination

Start program 345 N (Nitrite LR TNT) and prepare the sample by pouring 5 mL of sample to the Test 'N Tube vial. Mix the content of the vial to dissolve the powder and start the instrument timer for 20 minutes. Fill and empty Test 'N Tube vial with 5 mL of sample to prepare the blank-value vial. After that thoroughly clean the blank vial and sample vial. Install the instrument cap on the DR900 cell holder, put the blank vial in the instrument and push ZERO. Remove the blank-value vial, insert the sample vial and perform evaluation. The required measurement wavelength is 507nm (for spectrophotometers) or 520nm (for colorimeters).

Summary of method

Nitrite enters into reaction with sulfanilic acid forming intermediate diazonium salt. It couples with chromotropic acid to produce pink complex that must be measured using the abovementioned colorimeter.

Sample preparation

It is required to store the samples at or below 6 °C (43 °F) for up to 48 hours. The longer-term conservation of the sample is not recommended.