Sesame Oil
» Sesame Oil is the refined fixed oil obtained from the seed of one or more cultivated varieties of Sesamum indicum Linné (Fam. Pedaliaceae). It may contain suitable antioxidants.
Packaging and storage— Preserve in tight, light-resistant containers, and prevent exposure to excessive heat.
Labeling— Label it to indicate the name and quantity of any added antioxidant.
Identification— The peak responses for the eight major triglycerides, LLL, OLL, PLL, OOL, POL, OOO, SOL, and POO, elute between 0 and about 40 minutes, in the order specified, and at relative retention times of about 0.55, 0.65, 0.69, 0.77, 0.82, 0.93, 0.97, and 1.0, respectively, as obtained in the chromatogram of the Test solution in the test for Triglyceride composition.
Specific gravity 841: between 0.916 and 0.921.
Solidification range of fatty acids 401 The dry mixed fatty acids of it solidify between 20 and 25.
Free fatty acids 401 The free fatty acids in 10 g require for neutralization not more than 2.0 mL of 0.020 N sodium hydroxide.
Iodine value 401: between 103 and 116.
Saponification value 401: between 188 and 195.
Unsaponifiable matter 401: not more than 1.5%.
Triglyceride composition—
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile and methylene chloride (60:40). Make adjustments if necessary (see System Suitability under Chromatography 621).
note—The fatty acid radicals are designated as linoleic (L), oleic (O), palmitic (P), and stearic (S), and the common abbreviations for triglycerides used are as follows: trilinolein (LLL), 1,2-dilinoleoyl-3-oleoyl-rac-glycerol (OLL), 1,2-dilinoleoyl-3-palmitoyl-rac-glycerol (PLL), 1,2-dioleoyl-3-linoleoyl-rac-glycerol (OOL), 1-palmitoyl-2-oleoyl-3-linoleoyl-rac-glycerol (POL), triolein (OOO), 1-linoleoyl-2-oleoyl-3-stearoyl-rac-glycerol (SOL), and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (POO).
System suitability solution— Dissolve USP Sesame Oil Related Compound A RS and USP Sesame Oil Related Compound B RS in Mobile phase to obtain a solution having a known concentration of about 3 mg of each per mL. [note—USP Sesame Oil Related Compound A RS is OLL and USP Sesame Oil Related Compound B RS is PLL].
Test solution— Transfer about 200 mg of Oil, accurately weighed, to a 10-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a refractive index detector and two 4.6-mm × 25-cm columns in series that contain packings L1 and are maintained at a constant temperature of about 30. The flow rate is about 1.0 mL per minute. Chromatograph the System suitability solution, and record the peak areas as directed for Procedure: the relative retention times are about 0.93 for OLL and 1.0 for PLL; the resolution, R, between OLL and PLL is not less than 1.8; the relative standard deviation for replicate injections, determined from peak areas, is not more than 1.5%; and the relative standard deviation for replicate injections, determined from peak area ratios of OLL to PLL, is not more than 2.2%.
Procedure— Inject about 20 µL of the Test solution into the chromatograph, record the chromatogram, and measure the areas for the eight major triglyceride peaks, eluting from 0 to about 40 minutes, with relative retention times stated in the table below and in the order specified. Calculate the percentage of each of these triglycerides in the portion of Oil taken by the formula:
in which A is the peak area for each individual triglyceride; and B is the sum of the areas of all the peaks, excluding the solvent peak.
Triglyceride Relative Retention Time Composition (%)
LLL 0.55 7.0 to 19.0
OLL 0.65 13.0 to 30.0
PLL 0.69 5.0 to 9.0
OOL 0.77 14.0 to 25.0
POL 0.82 8.0 to 16.0
OOO 0.93 5.0 to 14.0
SOL 0.97 2.0 to 8.0
POO 1.0 2.0 to 8.0
Cottonseed oil— Mix 5 mL in a test tube with 5 mL of a mixture of equal volumes of amyl alcohol and a 1 in 100 solution of sulfur in carbon disulfide, warm the mixture carefully until the carbon disulfide is expelled, and immerse the tube to one-third of its depth in a boiling saturated solution of sodium chloride: no reddish color develops within 15 minutes.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Hong Wang, Ph.D.
(EM205) Excipient Monographs 2
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1335
Pharmacopeial Forum: Volume No. 30(5) Page 1668
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.