Division 7.1: Calculation in the case of back titration - Third Commission Directive of 27 September 1983 on the approximation of the laws of the Member States relating to methods of analysis necessary for checking the composition of cosmetic products (83/514/EEC)

Let:

V₁

the volume (in inillilitres) of the sodium hydroxide solution (4.6) used,

M₁

its actual molarity (4.6),

M₂

the actual molarity factor of the sulphuric acid solution (4.4),

m

the mass (in milligrams) of the test portion (6.1) taken,

then:

ammonia % (m/m) = \frac{({20 M}_{2} {- V}_{1} M_{1}) × 17×100}{0,4 m} = \frac{({20 M}_{2} {- V}_{1} M_{1}) × 4250}{m}

Division 7.1 Calculation in the case of back titration