2429800 Nitrate Reagent Set, 0.01-0.50 mg/L NO₃-N

Nitrate Reagent Set measures nitrate in the range of 0.01-0.50 mg/L NO₃-N in water, wastewater and seawater. The product uses Cadmium Reduction method (8192). Article 2429800 can be used to conduct 100 tests. The product is compatible with all Hach spectrophotometers or colorimeters except DR2000, DR2010, DR3000 and PC II.

Nitrate Reagent Set includes:

• NitriVer 3 Nitrite Reagent Powder Pillows (p/n 2107169)
• NitraVer 6 Nitrate Reagent Powder Pillows (p/n 2107249)

Before you start take into account the following:

• Collect the water, wastewater or seawater sample with clean glass or plastic bottles.
• It is required to analyze the sample instantly after collection for accurate testing results.
• Adjust the pH to 7 with 5 N sodium hydroxide solution and increase the sample temperature to room temperature before analysis.

Procedure for NO₃-N evaluation

Start program 351 N, Nitrate LR. After that mix 15 mL sample and NitraVer 6 Reagent Powder Pillow in the mixing cylinder. Add 10 mL of collected sample and NitriVer 3 Reagent Powder Pillow content in the sample cell. Then install the stopper on the sample cell and shake the sample cell content. Fill another sample cell with 10 mL of the sample to prepare the blank. Clean the blank cell and insert in the instrument. Remove the blank, clean the pretreated sample cell and install in the cell holder. The required measurement wavelength is 507 nm (for spectrophotometers) or 520 nm (for colorimeters).

Summary of method

Cadmium metal reduces nitrate to nitrite. The nitrite ion enters into reaction in acidic medium with sulfanilic acid  forming intermediate diazonium salt. The salt couples with chromotropic acid forming pink product.

Sample preparation

Instantly filter and store the collected sample at the temperature below 6 °C (43 °F) for up to 48 hours. Adjust the sample pH to 2 or less with concentrated sulfuric acid and store at or below 6 °C (43 °F) to conserve the sample for a maximum of 28 days.