HPLC Separation of All-Trans-ß-Carotene and Its Iodine-Induced Isomers Using a C30 Column

β-Carotene is generally regarded as the most commercially important and widely utilized carotenoid. It is used as a food coloring agent, an antioxidant, and an important and safe provitamin A source. Most β-carotene is naturally present in the trans form; however, some amounts of the cis form of β-carotene are also present in foods.

Using a typical reversed-phase column, such as a C18, it is difficult to separate trans-β-carotene and its cis isomers. Therefore a C30 stationary phase was applied to this separation challenge with the thought that the longer C30 alkyl chain of the stationary phase would be ideal for separating hydrophobic structurally related isomers. The work in this application note describes an efficient and convenient way to acquire the isomers of β-carotene by exposing it to iodine in sunshine.