Sesame Oil
»Sesame Oil is the refined fixed oil obtained from the seed of one or more cultivated varieties of Sesamum indicumLinné(Fam.Pedaliaceae).
Packaging and storage— Preserve in tight,light-resistant containers,and prevent exposure to excessive heat.
Identification— The peak responses for the eight major triglycerides,LLL,OLL,PLL,OOL,POL,OOO,SOL,and POO,elute between 0and about 40minutes,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 solutionin the test for Triglyceride composition.
Specific gravity á841ñ: between 0.916and 0.921.
Solidification range of fatty acids á401ñ— The dry mixed fatty acids of it solidify between 20and 25.
Free fatty acids á401ñ— The free fatty acids in 10g require for neutralization not more than 2.0mLof 0.020Nsodium hydroxide.
Iodine value á401ñ: between 103and 116.
Saponification value á401ñ: between 188and 195.
Unsaponifiable matter á401ñ: 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 Suitabilityunder Chromatography).
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— Transfer about 30mg each of OLLand PLL,accurately weighed,to a 10-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,and mix.
Test solution— Transfer about 200mg of Oil,accurately weighed,to a 10-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Chromatographic system (see Chromatography á621ñ)—The chromatograph is equipped with a refractive index detector and two 4.6-mm ×25-cm columns in series that contain packings L1and are maintained at a constant temperature about 30.The flow rate is about 1.0mLper minute.Chromatograph the System suitability solution,and record the peak areas as directed for Procedure:the relative retention times are about 0.93for OLLand 1.0for PLL;the resolution,R,between OLLand PLLis 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 OLLto PLL,is not more than 2.2%.
Procedure— Inject about 20µLof the Test solutioninto the chromatograph,record the chromatogram,and measure the areas for the eight major triglyceride peaks,eluting from 0to about 40minutes,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:
100(A/B),
in which Ais the peak area for each individual triglyceride;and Bis the sum of the areas of all the peaks,excluding the solvent peak.
Triglyceride Relative Retention Time Composition (%)
LLL 0.55 7.0to 19.0
OLL 0.65 13.0to 30.0
PLL 0.69 5.0to 9.0
OOL 0.77 14.0to 25.0
POL 0.82 8.0to 16.0
OOO 0.93 5.0to 14.0
SOL 0.97 2.0to 8.0
POO 1.0 2.0to 8.0
Cottonseed oil— Mix 5mLin a test tube with 5mLof a mixture of equal volumes of amyl alcohol and a 1in 100solution 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 15minutes.
Auxiliary Information— Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3071
Pharmacopeial Forum:Volume No.30(5)Page 1668
Phone Number:1-301-816-8262