Glycine
C2H5NO2 75.07
Glycine
[56-40-6].
(glye' seen).
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C2H5NO2 75.07
Glycine
[56-40-6].DEFINITION
Glycine contains NLT 98.5% and NMT 101.5% of glycine (C2H5NO2), calculated on the dried basis.
IDENTIFICATION
ASSAY
• Procedure
Sample:
150 mg of Glycine
Blank:
100 mL of glacial acetic acid
Titrimetric system
(See Titrimetry 
541
.)
541.)
Mode:
Direct titration
Titrant:
0.1 N perchloric acid VS
Endpoint detection:
Visual
Analysis:
Dissolve the Sample in 100 mL of glacial acetic acid, and add 1 drop of crystal violet TS. Titrate with the Titrant to a green endpoint. Perform the Blank determination.
Calculate the percentage of glycine (C2H5NO2) in the Sample taken:
Result = {[(VS 
VB) × N × F]/W} × 100
VB) × N × F]/W} × 100| VS | = | = Titrant volume consumed by the Sample (mL) |
| VB | = | = Titrant volume consumed by the Blank (mL) |
| N | = | = actual normality of the Titrant (mEq/mL) |
| F | = | = equivalency factor, 75.07 mg/mEq |
| W | = | = Sample weight (mg) |
Acceptance criteria:
98.5%–101.5% on the dried basis
IMPURITIES
• Residue on Ignition 281:
NMT 0.1%
281:
NMT 0.1%
• Chloride and Sulfate, Chloride 221
221
Standard solution:
0.10 mL of 0.020 N hydrochloric acid
Sample:
1 g of Glycine
Acceptance criteria:
NMT 0.007%
• Chloride and Sulfate, Sulfate 221
221
Standard solution:
0.20 mL of 0.020 N sulfuric acid
Sample:
3 g of Glycine
Acceptance criteria:
NMT 0.0065%
• Heavy Metals, Method I 231:
NMT 20 ppm
231:
NMT 20 ppm
• Hydrolyzable Substances
Sample solution:
100 mg/mL of Glycine
Analysis:
Boil 10 mL of the Sample solution for 1 min, and set aside for 2 h.
Acceptance criteria:
The solution appears as clear and as mobile as 10 mL of the same solution that has not been boiled.
SPECIFIC TESTS
• Loss on Drying 731:
Dry a sample at 105
for 2 h: it loses NMT 0.2% of its weight.
731:
Dry a sample at 105 for 2 h: it loses NMT 0.2% of its weight.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers.
• USP Reference Standards 11
11
USP Glycine RS 
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Huy T. Dinh, M.S.
Scientific Liaison 1-301-816-8594 |
(DS2010) Monographs - Dietary Supplements |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 3355