高效液相色谱柱后化学衍生法测定食品中的VB_1及叶酸含量

Simultaneous Determination of Vitamin B_1 and Folic Acid by High Performance Liquid Chromatography with Post-Column Chemical Derivation and Fluorescence Detection

研究柱后化学衍生荧光检测高效液相色谱分离测定食品中维生素B1和叶酸的方法。采用C18柱 ,以含有 3.5 %乙腈的pH5 .0磷酸盐缓冲溶液 (0 .0 5mol/L)作为流动相反相分离。色谱流出液在柱后与 0 .4 %的过二硫酸钾溶液在线汇合后流经一Teflon管化学反应器时 ,维生素B1和叶酸转化为强荧光产物 ,由荧光检测器测定。在最佳条件下 ,进样 2 0 μL ,维生素B1和叶酸工作曲线的线性范围分别为 0 .2 1～ 4 .2mg/L和0 .10～ 2 .0mg/L ,峰面积的相对偏差均为 2 .0 % ,回收率及实际样品测定结果满意。

A high performance liquid chromatographic method with post-column chemical derivation and fluorescence detection was developed for the determiantion of thiamine (VB_1) and folic acid in food. A C_ 18 column was used for separation, and elution was performed with a pH 5.0 phosphate buffer (0.05 mol/L) containing 3.5% acetonitrile. When the eluate was on-line converged with a 0.4% K_2S_2O_8 solution, VB_1 and folic acid in the eluate was transferred to an intensive fluorescence compound by post-column chemical derivation that occurred in a knotted coil reactor, and detected by a spectrofluorimeter(λ_ ex=350 nm,λ_ em=440 nm). Under optimized conditions, The linearity between peak area and concentration of VB_1 and folic acid existed in the range of 0.21～4.2 mg/L, 0.10～2.0 mg/L, and RSD of peak area was in the level of 2.0%, 2.0%, respectively. The developed method was applied to determine the thiamine and folic acid contents in tablet, and satisfactory results were obtained.