Abstract: A reversed-phase high-performance liquid chromatography(HPLC) method was 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 an energy beverage. Analytes were separated after solid phase extraction(SPE) with Supelco C18(500 mg/6 ml) cartridges and analyzed with HPLC on a Phenomenex C18(250 mm × 4.6 mm,5 μm) column with 0.1 mol/L KH2PO4(pH 7.0)-methanol(90:10,V/V) as mobile phase(0.5 ml/min) in isocratic mode. The identification of compounds was achieved by comparing their UV spectra with those of standard spectra in database and according to their respective time. The detection limit ranges from 0.05 to 0.2 mg/L and the accuracy of the method is between 94.71% and 97.03%.

Key words: high performance liquid chromatography, solid phase extraction, vitamin