高效液相色谱法同时测定食品中的B族维生素

用HPLC法同时测定食品中的四种B族维生素(B_1,B_2,B_5,B_6)。实验用0.4mol/L盐酸,120℃、15psi水解样品。分析以μBondapakC18(300mm×3.9mm)为色谱柱,甲醇:重蒸水:庚烷磺酸(PIC-B_7)=30:68:2(V:V:V)为流动相,选择紫外254nm,对B_1、B_2和B_5以及荧光(EX295nm、EM395nm)对B_6的双通道检测,可得到很好的分离图形。B_1、B_2、B_5和B_6的线性范围与相关系数各为10～50ng(r=0.998),5～40ng(r=0.999),5～40ng(r=0.993),5～50ng(r=0.999),最小检出限各为5、5、2、2ng。回收率各为91.3％～102％,103％～105％,92％～100％和99％～100％。与参比实验相比,所得食物中B族维生素含量差异不大,并与食物成分表公布的数据十分接近。

SIMULTANEOUS DETERMINATION OF THIAMINE, RIBOFLAVIN, NIACIN AND PYRIDOXINE IN FOODS BY HPLC

A high performance liquid chromatographic assay has been developed for the simultaneous determination of four water soluble vitamins,thia min, ribo-flavin, uiacin and pyridoxine, in cereal products and fresh vegetables. For hydrolyzing sample in 0.4 mol/L HCL, autoclaving at 120℃, 15 psi for 30 minutes, a μBondapak column (300mm × 3.9mm, Waters Co), a mobile phase of methanol-water (30:70) (0.005 mol/L heptanesulfonic acid) and a flow rate of 1.0ml/min gave the most satisfactory separation of the four vitamins. A double channel detector was used: three vitamins (B1, B2 and B5) were detected by UV spectrophotometry (254 nm) first, pyridoxine (B6) was detected by fluorometry (EX 290 nm, EM 390 nm) afterwards. Detection limits were 2, 5, 5 and 2ng, linear ranges were 5-40 ng, 5-50 ng, 5-40 ng and 5-50 ng for B1, B2, B5 and Be, respectively. Recoveries were 91.3%-102% (B1), 103%-105% (B2), 92%-100% (B5) and 99%-100% (B6), comparing with reference method and checking with food composition tables, very satisfactory results were obtained by this method.