1982 Volume 28 Issue 2 Pages 111-113
Caffeine and sodium benzoate were determined by high performance liquid chromatography with a UV detector by use of stainless column (4.0 mm×0.15 m) packed with Nucleosil 5C18. Mobile phase was M/30 KH2PO4+M/30 Na2HPO4·2H2O-methanol (70 : 30). The sample was dissolved in 20% aqueous methanol. Determination was carried out successfully by using antipyrine as an internal standard and by maintaining the temperature at 40°C. The recovery of sodium benzoate and caffeine from synthetic mixtures were 97.2±1.0% and 99.8±1.1%. This method was applied to three kinds of pharmaceutical preparations. The contents of sodium benzoate and caffeine were 48.4-50.1% and 49.0-49.6%.
