Process for distinguishing natural alpha-tocopherol from synthetic alpha-tocopherol

摘要

d-a -Tocopherol is distinguished from dl-a -tocopherol, which has a different biological activity, by reacting the a -tocopherol with a ferricyanide in aqueous alkaline solution, which is effective to convert d-a -tocopherol to a product having positive specific optical rotation and ineffective to convert dl-a -tocopherol to a product having specific optical rotation, and ascertaining the optical activity of the product. A d-a -tocopheryl ester may be distinguished from a dl-a -tocopheryl ester by first hydrolysing the ester to the corresponding a -tocopherol and then reacting it with the ferricyanide. Examples are given.ALSO:d-a -tocopherol is distinguished from dl-a -tocopherol, which has a different biological activity, by reacting the a -tocopherol with a ferricyanide in aqueous alkaline solution, which is effective to convert d-a -tocopherol to a product having positive specific optical rotation and ineffective to convert dl-a -tocopherol to a product having specific optical rotation, and ascertaining the optical activity of the product. A d-a -tocopheryl ester may be distinguished from a dl-a -tocopheryl ester by first hydrolysing the ester to the corresponding a -tocopherol and then reacting it with the ferricyanide. Examples are given. The test distinguishes between natural (d) and synthetic (dl) a -tocopherols.