Use the pipette to absorb 1 ml ammonia liquid and inject in the conical flask, add proper amount of demineralized water to about 25mL and shake well, drop 2 ~ 3 drops of methyl orange indicator, then use 0.05 mol/L sulfuric acid standard solution for titration, until the solution turn into orange from yellow record the consumption volume of sulfuric acid standard solution, the calculation is as follows:
                       2×M·a×17
        NH3=                           ×1000 mg/L
                              V
Where
M - showing the molar concentration of H2SO4 for titration -  mol/L.
a - showing the volume of H2SO4 standard solution for titration, mL.
V - showing the volume of ammonia liquid , mL.
17- Showing the molar mass of ammonia  g/moL.