Determination of Ammonia
Determination of Ammonia
Principle :
Procedure :
Digestion is not needed as the objective is to measure only the ammonia.
- Weigh the sample (S grammes or ml if a liquid) and then put in to the distillation flask
- add about 5 g magnesium oxide then add 300 ml distilled water after that attach to distillation system.
- add 50 ml boric acid solution to the receiving flask, boil the solution and collect the distillate until 200 - 250 ml is obtained. Then titrate with sulphuric acid 0.1 N until the colour goes from white pink.
V = volume of 0.1N H2SO4 used in the titration.
Calculation :
1000 ml N H2SO4 = (14+3 = 17) g of NH3
1000 ml 0.1 N H2SO4 = 1.7 g NH3
1 ml 0.1 N H2SO4 = 0.0017 g NH3
V * 0.0017 = g NH3 in the sample
Ammonia (mg/litre) = (V * 0.0017)/S *1000 * 1000