Proceed with the extraction and isolation of the residue obtained by hydrolysis as directed for Test solution for alpha tocopheryl acid succinate in the Identification test under Vitamin E. Immediately dissolve the residue in dehydrated alcohol, transfer to a 250-mL volumetric flask, dilute with dehydrated alcohol to volume, and mix.
To 10 mL of Test solution
add, with swirling, 2 mL of nitric acid, and heat at about 75
for 15 minutes: a bright red or orange color develops.
Transfer an accurately measured volume of Test solution
, equivalent to about 100 mg of the test specimen, to a separator, and add 200 mL of water. Proceed as directed in Identification
under Vitamin E
, beginning with Extract first with 75 mL.
The retention time of the major peak in the chromatogram of the Assay preparation
is the same as that of the Standard preparation,
both relative to the internal standard, as obtained in the Assay
Liquid forms of Vitamin E Preparation
Dissolve 1.0 g in 25 mL of a mixture of equal volumes of alcohol and ether (which has been neutralized to phenolphthalein with 0.1 N sodium hydroxide), add 0.5 mL of phenolphthalein TS, and titrate with 0.10 N sodium hydroxide until the solution remains faintly pink after shaking for 30 seconds: not more than 1.0 mL of 0.10 N sodium hydroxide is required.
Proceed with Vitamin E Preparation as directed for the appropriate Assay
under Vitamin E
, substituting the following for the Assay preparation
[NOTEUse low-actinic glassware.]
If the Preparation is in the liquid form
, transfer an accurately weighed portion of Vitamin E Preparation, equivalent to about 50 mg of the specified form, to a 50-mL volumetric flask, dissolve in Internal standard solution, dilute with Internal standard solution to volume, and mix.
If the Preparation is in the solid form
, transfer an accurately weighed portion of Vitamin E Preparation, equivalent to about 50 mg of Vitamin E, into a flask suitable for refluxing. Add about 5 mL of water, and heat on a water bath at 60
for 10 minutes. Add about 25 mL of alcohol, and reflux for 30 minutes. Cool, and transfer to a separator with the aid of 50 mL of water and 50 mL of ether. Shake vigorously, allow the layers to separate, and collect each in individual separators. Extract the aqueous layer with two 25-mL portions of ether, combining the extracts with the original ether layer. Wash the combined ether extracts with one 25-mL portion of water, filter the ether solution through 1 g of granular anhydrous sodium sulfate, and evaporate the ether solution on a water bath, controlled at a temperature that will not cause the ether solution to boil over, with the aid of a stream of nitrogen. Remove the container from the water bath when 5 mL remains, and complete the evaporation without the application of heat. Dissolve the residue in 50.0 mL of Internal standard solution
, and mix.