Cetyl Alcohol
» Cetyl Alcohol contains not less than 90.0 percent of cetyl alcohol (C16H34O), the remainder consisting chiefly of related alcohols.
Packaging and storage—
Preserve in well-closed containers.
Identification—
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the System suitability solution, as obtained in the Assay.
Acid value
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Iodine value
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Hydroxyl value—
Place about 2 g, accurately weighed, 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
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Assay—
System suitability solution—
Dissolve accurately weighed quantities of USP Cetyl Alcohol RS and USP Stearyl Alcohol RS in dehydrated alcohol to obtain a solution having known concentrations of about 9 mg per mL and 1 mg per mL, respectively.
Assay preparation—
Dissolve 100 mg of Cetyl Alcohol in 10.0 mL of dehydrated alcohol, and mix.
Chromatographic system (see Chromatography
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Procedure—
Inject about 2 µL of the Assay preparation into the chromatograph, record the chromatogram, and measure the areas for the major peaks. Calculate the percentage of C16H34O in the portion of Cetyl Alcohol taken by the formula:
100(rU / rs)
in which rU is the peak area for cetyl alcohol obtained from the Assay preparation; and rs is the sum of the areas of all the peaks except the solvent peak.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
Chromatographic Column—
USP32–NF27 Page 1203
Pharmacopeial Forum: Volume No. 31(2) Page 494
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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