^#.^t41: TLC of Vitamins Including Nicotinic Acid Derivatives
Vitamins are dened as biologically active organic compounds, controlling agents that are essential for an organism’s normal health and growth, not synthesized within the organism, available in the diet in small amounts, and carried in the circulatory system in low concentrations to act on target organs or tissues. Vitamins are classied according to their solubility in water and in fats. Hydrophilic vitamins are the vitamins of the groups, B1 (thiamine), B2 (riboavin), B3 (PP, niacin, nicotinamide, nicotinic acid), B5 (panthenol and pantothenic acid), B6 (pyridoxal), B7 (biotin), B9 (folic acid), B12 (cobalamin), and C (ascorbic acid). Lipophilic vitamins are the vitamins of the groups A, D, E, and K. In vitamin chromatography, the following problems should be solved: identication and the determination of vitamins in pharmaceutical preparations and identication and determination of vitamins and related substances in natural materials and foodstuffs. The isolation of the vitamins, their metabolites, and related substances from natural material is the most difcult task (De Leenheer et al. 2000; Eitenmiller et al. 2008).