Determination of seven water-soluble vitamins in tarhana, a traditional Turkish cereal food, by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic procedure has been developed for determination of water-soluble vitamins (ascorbic acid, niacin, panthothenic acid (vitamin B5), pyridoxine (vitamin B6), thiamine (vitamin B1), folic acid, and riboflavin (vitamin B2)) in tarhana samples, a traditional Turkish cereal food. Sample-treatment entails SPE with Sep-Pak C18 (500-mg) cartridges. The water-soluble vitamins were analyzed by HPLC on a Discovery C-18 150 mm × 4.6 mm column with 0.1 mol L −1 KH2PO4 (pH 7.0)–methanol, 90:10, as mobile phase (0.7 mL min −1 ) in isocratic mode. Identification of compounds was achieved by comparing their retention times and UV spectra with those of standards stored in a data bank. The detection limits ranged from 0.1 to 0.5 mg L −1 . The accuracy of the method was tested by measuring average recovery; values ranged between 96.51 and 99.40%.