摘要: A high performance liquid chromatographic assay has been developed for the simultaneous determination of five water soluble vitamins:thimine, riboflavin, niacin, pyridoxine and folic acid in cereal products and fresh vegetables. Food samples were hydrolyzed in 0.4 mol/L HCl, autoclaved at 120℃ 15 psi for 20 minutes, using a μ-Bondapak column (3.9×300mm, Waters Co.), a mobile phase of methanol-water (30:70) (0.005 mol/L heptanesulfonic acid) and a flow rate of 1.0 ml/min gave the most satisfactory separation of the five water soluble vitamins. A double channel deteetion was used: four vitamins (B₅, folic acid, B₂, B₁) were detected hy UV spectrophotometry (254 nm) first, pyridoxine (B₆) was detected by fluoromelry (EX 290nm, EM 395 nm) afterwards. Detection limits were 2, 5, 5, 2 and 5ng, linear ranges were 5-10ng, 5-50ng, 5-40ng, 5-50ng and 10-50ng for B₁, B₂, B₅, B₆ and folic acid respectively. Recoveries were 92-100%(B₅), 51-52% (folic acid), 103-105% (B₂), 99-100% (B₆) and 91.3-102% (B₁) respectively. In comparison with a reference method and checking with food composition tables, very satisfactory results were obtained by this method.