Ammonium Carbonate
Carbonic acid, monoammonium salt mixture with ammonium carbamate;
Monoammonium carbonate mixture with ammonium carbamate
[8000-73-5].
(a moe' nee um kar' bo nate).
Carbonic acid, monoammonium salt mixture with ammonium carbamate;
Monoammonium carbonate mixture with ammonium carbamate
[8000-73-5].DEFINITION
Ammonium Carbonate consists of ammonium bicarbonate (NH4HCO3) and ammonium carbamate (NH2COONH4) in varying proportions. It yields NLT 30.0% and NMT 34.0% of ammonia (NH3).
IDENTIFICATION
• A.
When heated, it is volatilized without charring, and the vapor is alkaline to moistened litmus paper. A solution (1 in 20) effervesces with acids.
ASSAY
• Procedure
Sample solution:
Place 10 mL of water in a weighing bottle, tare the bottle and its contents, add 2 g of Ammonium Carbonate, and weigh.
Titrimetric system
(See Titrimetry 
541
.)
541.)
Mode:
Residual titration
Titrant:
1 N sulfuric acid VS
Back-titrant:
1 N sodium hydroxide VS
Blank:
50.0 mL of 1 N sulfuric acid VS, accurately measured
Endpoint detection:
Colorimetric
Analysis:
Transfer the Sample solution to a 250-mL flask, add 50.0 mL of 1 N sulfuric acid VS, and when the solution has been effected, add methyl orange TS. Titrate the excess acid with 1 N sodium hydroxide VS. Perform a blank determination. Calculate the percentage of ammonia (NH3) in the sample taken.
Result = [(B 
V) × N × F × 100]/W
V) × N × F × 100]/W
| B | = | = 1 N sodium hydroxide VS consumed by the Blank (mL) |
| V | = | = 1 N sodium hydroxide VS consumed by the sample (mL) |
| N | = | = actual normality of the Back-tritrant (mEq/mL) |
| F | = | = equivalency factor, 17.03 mg/mEq |
| W | = | = weight of the sample (mg) |
Acceptance criteria:
30.0%–34.0%
IMPURITIES
• Residue on Ignition 281:
NMT 0.1%
281:
NMT 0.1%
• Chloride and Sulfate, Chloride 221:
A 2.0-g portion shows no more chloride than corresponds to 0.10 mL of 0.020 N hydrochloric acid (0.0035%).
221:
A 2.0-g portion shows no more chloride than corresponds to 0.10 mL of 0.020 N hydrochloric acid (0.0035%).
• Chloride and Sulfate, Sulfate 221:
A 2.0-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.005%).
221:
A 2.0-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.005%).
• Heavy Metals, Method I 231
231
Test preparation:
Reduce to a coarse powder, and volatilize 2 g on a steam bath. Add 1 mL of 3 N hydrochloric acid, and evaporate to dryness. Dissolve the residue in 2 mL of 1 N acetic acid, and add water to make 25 mL.
Acceptance criteria:
NMT 10 ppm
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight, light-resistant containers, and store at a temperature not above 30
.
.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
USP35–NF30 Page 1698