HG/T2785-2012 Ammonium Bisulfite for Industrial Use
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- Apr 3,2026
Summary
Accurately transfer 5–10 mL of Rong Yier (5.2.3.1) into a 250 mL iodometric flask containing 25 mL of iodine standard solution, and shake well. Titrate with sodium thiosulfate standard titration solution until the solution turns pale yellow, then add 2 mL of starch solution as an indicator.
5.3.3 Determination
Accurately transfer 5–10 mL of Rong Yier (5.2.3.1) into a 250 mL iodometric flask containing 25 mL of iodine standard solution, and shake well. Titrate with sodium thiosulfate standard titration solution until the solution turns pale yellow, then add 2 mL of starch solution as an indicator. Continue titration until the blue color just disappears as the endpoint.
During the aforementioned measurements, blank tests were performed without adding the test solution, following the specified procedures.
5.3.4 Presentation of Analysis Results
The ammonium sulfite content expressed as a percentage by mass (X2) is calculated according to Equation (2):
……………………………（2）
Where: V1 — the volume (in mL) of standard sodium hydroxide titration solution consumed during titration of ammonium bisulfite;
V2 — Volume of sodium thiosulfate standard titration solution consumed during testing, in mL;
V3 — Volume of sulfuric acid standard titration solution consumed in blank test, mL
V4 — Volume of test solution aspirated during measurement, mL;
C-Actual concentration of sodium thiosulfate standard titration solution, mol/L;
m — the mass of the sample, in grams;
0.05807-with 1.00 mL of ammonium thiosulfate standard titration solution [C(Na2S2O3) = 1.000 mol]
]/The equivalent mass of ammonium sulfite expressed in grams.