HG/T 2784-2012 Ammonium Sulfite for Industrial Use
4.2.5.4.2 If the sample contains ammonium bicarbonate, the mass fraction of ammonium sulfate [(NH4)2SO4] (expressed as%) shall be calculated using Equation (5):
……………………（5）
In the formula:
V — the volume of the sodium hydroxide standard titration solution (4.2.5.2.3) consumed, measured in milliliters (ml);
c—The precise concentration of the standard sodium hydroxide titration solution, measured in molar per liter (mol/L).
M-the molar mass of ammonium sulfate, measured in grams per mole (g/mol) (M=132.13);
m-the numerical value of the sample mass, in grams (g);
—The mass fraction of ammonium bisulfite, as determined in Section 4.2.2, expressed as a percentage.
—The mass fraction of ammonium bicarbonate, as determined in Section 4.2.4, expressed as a percentage.
0.9850-the conversion factor of ammonium bisulfite [(NH4)2SO3·H2O] to ammonium sulfate [(NH4)2SO4];
0.8357-The conversion factor for ammonium bicarbonate (NH4HCO3) to ammonium sulfate [(NH4)2SO4].
The arithmetic mean of two parallel test results shall be taken as the test result. The absolute difference of parallel test results shall not exceed 0.40%.
