Myristyl Alcohol
(mir is' til al' ka hol).
DEFINITION
Myristyl Alcohol contains NLT 90.0% of myristyl alcohol (C14H30O), the remainder consisting chiefly of related alcohols.
IDENTIFICATION
• A.
The retention time of the major peak of the Sample solution corresponds to that of the System suitability solution, as obtained in the Assay.
ASSAY
• Procedure
System suitability solution:
9 mg/mL of USP Myristyl Alcohol RS and 1 mg/mL of USP Cetyl Alcohol RS in alcohol
Sample solution:
10 mg/mL of Myristyl Alcohol in dehydrated alcohol
Chromatographic system
Mode:
GC
Detector:
Flame ionization
Column:
3-mm × 2-m, packed with 10% liquid phase G2 on support S1A
Temperature
Column:
205
Detector:
250
Injector port:
275
Carrier gas:
Helium
Injection size:
2 µL
System suitability
Sample:
System suitability solution
Suitability requirements
Resolution:
NLT 4.0 between cetyl alcohol and myristyl alcohol
Relative standard deviation:
NMT 1.5%
Analysis
Sample:
Sample solution
Calculate the percentage of myristyl alcohol (C14H30O) in the portion of Myristyl Alcohol taken:
Result = (rU/rT) × 100
| rU | = | = peak area of myristyl alcohol from the Sample solution |
| rT | = | = sum of the peak areas except the solvent peak from the Sample solution |
Acceptance criteria:
NLT 90.0%
SPECIFIC TESTS
• Melting Range or Temperatue, Class II 
741
:
36 to 42
741:
36 to 42
• Fats and Fixed Oils, Acid Value 401:
NMT 2
401:
NMT 2
• Fats and Fixed Oils, Hydroxyl Value 401
401
Sample:
Place 2 g in a dry, glass-stoppered, 250-mL flask, and add 2 mL of pyridine, followed by 10 mL of toluene. To the mixture add 10.0 mL of a solution of acetyl chloride, prepared by mixing 10 mL of acetyl chloride with 90 mL of toluene. Insert the stopper in the flask, and immerse in a water bath heated at 60 to 65 for 20 min. Add 25 mL of water, again insert the stopper in the flask, and shake vigorously for several minutes to decompose the excess acetyl chloride.
to 65 for 20 min. Add 25 mL of water, again insert the stopper in the flask, and shake vigorously for several minutes to decompose the excess acetyl chloride.
Titrimetric system
(See Titrimetry 541.)
541.)
Mode:
Residual titration
Titrant:
Acetyl chloride
Back titrant:
1 N sodium hydroxide VS
Blank:
Proceed as directed for the Sample, omitting Myristyl Alcohol.
Endpoint detection:
Colorimetric
Analysis:
Add 0.5 mL of phenolphthalein TS to the Sample and Blank. Titrate each to a permanent pink endpoint with 1 N sodium hydroxide VS, shaking the flask vigorously toward the end of the titration to maintain the contents in an emulsified condition.
Calculate the hydroxyl value:
Result = [(VU 
VB) × F]/W
VB) × F]/W
| VU | = | = volume of 1 N sodium hydroxide consumed by the Sample (mL) |
| VB | = | = volume of 1 N sodium hydroxide consumed by the Blank (mL) |
| F | = | = equivalent weight of potassium hydroxide, 56.1 mg/mEq |
| W | = | = weight of the Sample (g) |
Acceptance criteria:
250–267
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers.
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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 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 1873
Pharmacopeial Forum: Volume No. 28(2) Page 424