Nitrate Testing - UV Vis Spectroscopy

Spectrophotometric determination of nitrate in water and soil

This method describes a simple and convenient procedure for the determination of nitrate (NO3-) in water and soil. To learn more, please proceed to download the application note below.

Nitrates in water, food and soil

In the food and beverage industry, manufacturers often add nitrates for preservative and aesthetic purposes. Since it is harmful to health above a certain limit, there are regulations regarding the concentration of nitrates in food and nitrate testing is therefore necessary to ensure compliance. Nitrate content in soil is also an important property and the correct level must be tested to ensure optimal growth conditions. This method is applicable to many different samples other than water and soil, depending on the desired application.

How is nitrate content determined spectrophotometrically?

The reaction of nitrite (NO2-) with sulfanilamide and the Griess reagent leads to a pink color azo dye. Since nitrate in aqueous samples predominantly exists as NO3-, it needs to be reduced to nitrite first. The concentration of nitrite/nitrate is determined by measuring the absorbance at a fixed wavelength with a UV Vis spectrophotometer. For more details, see the application note below.