(glye' seen).
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C2H5NO2 75.07
Glycine     [56-40-6].
Glycine contains NLT 98.5% and NMT 101.5% of glycine (C2H5NO2), calculated on the dried basis.
•  Procedure
Sample:  150 mg of Glycine
Blank:  100 mL of glacial acetic acid
Titrimetric system 
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
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
•  Residue on Ignition 281: NMT 0.1%
•  Chloride and Sulfate, Chloride 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
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
•  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.
•  Loss on Drying 731: Dry a sample at 105 for 2 h: it loses NMT 0.2% of its weight.
•  Packaging and Storage: Preserve in well-closed containers.
•  USP Reference Standards 11
USP Glycine RS Click to View Structure
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
(DS2010) Monographs - Dietary Supplements
Reference Standards RS Technical Services
USP35–NF30 Page 3355