- Description: Clear, colourless or slightly greenish-yellow, viscous, oily liquid.
- Solubility: Practically insoluble in water, freely soluble in acetone, in anhydrous ethanol and in fatty oils.
- Optical rotation : -0.01° to + 0.01°.
Dissolve 2.50 g in anhydrous ethanol R and dilute to 25.0 mL with the same solvent.
- B. Infrared absorption spectrophotometry
Comparison a.-tocopheryl acetate CRS.
- Thin-layer chromatography
Test solution Dissolve about 10 mg of the substance to be examined in 2 mL of cyclohexane R.
Reference solution Dissolve about 10 mg of α-tocopheryl acetate CRS in 2mL of cyclohexane R.
Plate TLC silica gel F 254 plate R.
Mobile phase ether R, cyclohexane R (20:80 V/V).
Application 10 µL
Development Over 2/3 of the plate.
Drying In a current of air.
Detection Examine in ultraviolet light at 254 nm.
Results The principal spot in the chromatogram obtained with the test solution is similar in position and size to the principal spot in the chromatogram obtained with the reference solution.
- Related Substances
Gas chromatography : use the normalization procedure.
Internal standard solution :On Dissolve 1.0 g of squalane R in cyclohexane R and dilute to 100.0 mL with the same solvent.
Test solution (a) Dissolve 0.100 g of the substance to be examined in 10.0 mL of the internal standard solution.
Test solution (b) Dissolve 0.100 g of the substance to be examined in 10 mL of cyclohexane
Reference solution (a) Dissolve 0.100 g of α-tocopheryl acetate CRS in 10.0 mL of
the internal standard solution.
Reference solution (b) Dissolve 10 mg of the substance to be examined and 10 mg of all-rac
– α-tocopherol R in cyclohexane R and dilute to 100.0 mL with the same solvent.
Reference solution (c) Dissolve 10 mg of all-rac- α -tocopheryl acetate for peak
identification CRS (containing impurities A and B) in cyclohexane R and dilute to 1 mL
with the same solvent.
Reference solution (d) Dilute 1.0 mL of test solution (b) to 100.0 mL with cyclohexane.
Dilute 1.0 mL of this solution to 10.0 mL with cyclohexane R.
– material: fused silica
– size: l = 30 m, Ø= 0.25 mm
– stationary phase: poly(dimethyl)siloxane R (film thickness 0.25 um).
Carrier gas helium for chromatography R.
Flow rate 1 ml/min.
Split ratio 1:100.
– column: 280°C;
– injection port and detector: 290°C.
Detection Flame :ionisation.
Injection 1 µL of test solution (b) and reference solutions (a), (b), (c) and (d); inject
directly onto the column or via a sufficiently inert, glass-lined injection port using an
automatic injection device or other reproducible injection method.
Run time Twice the retention time of all-rac-α-tocopheryl acetate.
Identification of impurities Use the chromatogram supplied with all-rac-α-tocopheryl
acetate for peak identification CRS and the chromatogram obtained with reference solution
(c) to identify the peaks due to impurities A and B.
Relativeretention With reference to all-rac-α-tocopheryl acetate (retention time =about
15 min):squalane =about 0.4; impurity A =about 0.7; impurity B =about 0.8; impurity C
= about 0.9;impurities D and E =about 1.05 (eluting immediately after the all-rac-α
– tocopheryl acetate peak).
– resolution: minimum 3.5 between the peaks due to impurity C and all-rac-α-tocopheryl
acetate in the chromatogram obtained with reference solution (b);
– in the chromatogram obtained with reference solution (a),the area of the peak due to
impurity C is not greater than 0.2 per cent of the area of the peak due to all-rac-α-
– impurities A, C: for each impurity, maximum 0.5 per cent
– impurity B: maximum 1.5 per cent
– sum of impurities D and E: maximum 1.0 per cent
– any other impurity: for each impurity, maximum 0.25 per cent
– total: maximum 2.5 per cent
– disregard limit: the area of the principal peak in the chromatogram obtained with
reference solution (d) per cent).
Gas chromatography as described in the test for related substances with the
Injection Test solution (a) and reference solution (a).
System suitability Reference solution (a):
– symmetry factor. minimum 0.6 for the principal peak.
Calculate the percentage content of C31H5203 from the declared content of α-tocopheryl acetate .