HG/T 2784-2012 Ammonium Sulfite for Industrial Use

The mass fraction of ammonium sulfite, expressed as%, is calculated according to formula (6):

……………………（6）

In the formula:

The volume of sodium thiosulfate standard titration solution (4.3.2.2.2) consumed in the blank test, measured in milliliters (ml).

—The volume of the standard sodium thiosulfate titration solution (4.3.2.2.2) consumed, measured in milliliters (ml);

c-the precise concentration of sodium thiosulfate standard titration solution, measured in molar per liter (mol/L);

M-the molar mass of ammonium sulfite, measured in grams per mole (g/mol) (M=116.14);

m-the numerical value of the mass of the aliquot, in grams (g).

The arithmetic mean of the two parallel test results shall be taken as the test result. The absolute difference between the two parallel test results shall not exceed 0.15%.

4.3.3 Determination of pH Value

Determination shall be performed in accordance with the provisions of GB/T 9724.

5 Inspection Rules

5.1 Solid ammonium sulfite shall generally be produced in batches corresponding to the same specification of finished product quantity on the same day, with a maximum batch size not exceeding 20 tons. The manufacturer shall ensure that each batch of products released from the factory complies with the requirements of this standard; liquid ammonium sulfite transported in railway tank cars, storage tanks, or truck tankers shall be counted as one batch per vehicle or tank.