2672245 Nitrogen Cuvette Test, 0.5-25 mg/L N

16 mm Test 'N Tube Cuvette test measures 0.5-25 mg/L N in water and wastewater. The product uses persulphate digestion method (10071). Article 2672245 can be used for 25-50 tests. TNT product can be evaluated on DR900 only.

Before you start take into account the following:

• It is required to digest the water or wastewater sample for total nitrogen evaluation.
• It is recommended to collect the sample using clean glass or plastic bottles.

Procedure for N determination

Start the DRB200 Reactor and prepare the sample vial and blank vial (see manual for detailed information regarding preparation of each vial). Shake and insert vials in the reactor for 30 minutes. After that start program 350 N (Total LR TNT). Pour the content of Total Nitrogen (TN) Reagent A Powder Pillow to each vial, shake the vial content and add TN Reagent B Powder Pillow to each vial. Prepare the sample vial and blank vial and thoroughly clean the outside of each vial. Put the blank vial in the instrument and push ZERO. Insert the sample vial and evaluate water and wastewater sample.

Summary of method

Alkaline persulfate digestion converts nitrogen to nitrate. Sodium metabisulfite is added after the digestion to eliminate halogen oxide interferences. Nitrate enters intro reaction with chromotropic acid under strongly acidic conditions forming yellow complex that is required to be analyzed photometrically.

Sample preparation

It is recommended to evaluate the sample as soon as possible to receive precise testing results. Article 2672245 storage conditions are between 10 °C and 25 °C.