在线富集毛细管液相色谱法分析脂溶性维生素和β-胡萝卜素

Capillary liquid chromatographic determination of fat-soluble vitamins and β-carotene in corns with on-line concentration

以硅胶基质ODS整体柱为分离柱,建立了毛细管液相色谱-紫外/可见光度法测定脂溶性维生素和β-胡萝卜素的方法。对流动相组成、流速、样品溶解液和进样体积等参数进行了系统优化,采用溶剂梯度区带压缩效应作为在线富集技术来提高检测灵敏度。与传统的进样方式相比,采用溶剂梯度区带压缩在线富集技术时,在不损失分辨率的前提下,可通过增大进样体积将脂溶性维生素和β-胡萝卜素的检测灵敏度提高34～60倍。方法可用于检测玉米中的痕量维生素E。

A capillary liquid chromatographic method was developed for the simultaneous determination of fat-soluble vitamins and β-earotene, in which UV-Vis spectrometer was used as the detector and a monolithic silica-ODS column as the separation colmnn. The parameters, including mobile phase composition, flow rate, sample matrix and injection volume, were optimized. Solvent gradient zone sharpening effect was utilized as an on-line concentration technique to enhance the detection sensitivity by injection of large volumes of the sample dissolved in a non-eluting solvent without compromising the resolution. Compared with the conventional injection mode, the enhancement in the detection sensitivities of fat-soluble vitamins and β-carotene using the on-line concentration technique was in the range of 34 to 60- fold. The developed method was successfully applied to evaluation of trace amounts of vitamin E in toms.