Ammonia in Water - NH3(aq)

The content of ammonia in water (ammonium hydroxide) can be determined quickly and easily by refractive index measurement.

Aqueous ammonia - a weak base with high impact

The annual worldwide production of ammonia (NH3) is 125 million tonnes, which consumes 3 % of the energy produced worldwide. Over 90 % of the ammonia is synthesized by the Haber-Bosch process. This paves the way for the production of synthetic nitrogen fertilizers, which consume over 80 % of the processed ammonia. Ammonia is also commercially and commonly available as an aqueous solution; the most common commercial formulation is 28 % to 32 % NH3. Other application areas are:

  • Basic chemicals to produce nitrogen compounds (fertilizer, explosives)
  • Refrigerant in vapor absorption refrigeration systems
  • Medical purposes (to produce pharmaceuticals, e.g. steroids)
  • Medical purposes (to produce pharmaceuticals, e.g. steroids)
  • Leakage test solution in chlorination installations
  • Reducing agent in catalyst systems (selective catalytic reduction - SCR)

The Abbemat refractometer family from Anton Paar

Conventional determination of the ammonia content in water is done by titration, which is a time-consuming process. Furthermore, ammonia gas escapes from the solution and, depending on the time of the measurement, this may lead to incorrect measurement results. 

An Abbemat refractometer from Anton Paar directly shows the NH3 content in water (g /100 g) within seconds. From the concentration a corresponding density value can also be calculated. As two to three drops of sample are enough, the costs of waste disposal are lower and the process is more environmentally-friendly than conventional titration. Evaporation of ammonia can be diminished by using a micro flow cell for sample filling. All Abbemat refractometers have a built-in Peltier temperature control with an accuracy of up to ± 0.03 °C. The ammonia content can be determined with an accuracy of up to ± 0.043 in the range of 0 g to 30 g/100 g.

Learn more about the Abbemat refractometer

Other relevant instruments

For precise density measurement a density meter from Anton Paar can be used. The correlation between density and concentration can also be calculated.

Good to know

The Abbemat refractometers from Anton Paar are ideal for determining the content of ammonia solutions.