Gregory J F
J Assoc Off Anal Chem. 1984 Sep-Oct;67(5):1015-9.
The objective of most methods for determination of folates in foods and other biological materials is to estimate the total folacin content of the sample. Because folacin comprises a diverse group of related compounds exhibiting similar biological activity, the analytical method must be capable of measuring all of the folates. Methods have been developed for separation of folates in their monoglutamyl form by using anion-exchange, paired-ion reverse phase, or conventional reverse phase liquid chromatography (LC). The application of these separations to determination of folates in foods and other biological materials has been limited largely by the need for development of adequate preparative methods and sufficiently sensitive and specific detection procedures. Although LC with ultraviolet absorption detection has been successful in certain limited applications, the development of fluorometric detection methods has permitted LC determination of folates in a wide range of materials. Tetrahydrofolic acid and its substituted derivatives are detected by monitoring their native fluorescence in an acid mobile phase, while folic acid and certain other folates are measured by using an oxidative post-column fluorogenic derivatization system. Methods also have been developed for determination of the polyglutamyl chain length distribution of folates in biological materials. In total, these procedures permit a direct determination and characterization of folacin compounds.
大多数用于测定食品和其他生物材料中叶酸的方法，其目的是估算样品中总叶酸含量。由于叶酸包含一组具有相似生物活性的相关化合物，因此分析方法必须能够测定所有的叶酸。人们已经开发出一些方法，通过使用阴离子交换、离子对反相或传统反相液相色谱（LC）来分离单谷氨酰形式的叶酸。这些分离方法在食品和其他生物材料中叶酸测定方面的应用，在很大程度上受到开发适当的制备方法以及足够灵敏和特异的检测程序的需求所限制。尽管带有紫外吸收检测的液相色谱在某些有限的应用中取得了成功，但荧光检测方法的发展使得液相色谱能够测定多种材料中的叶酸。通过监测它们在酸性流动相中的固有荧光来检测四氢叶酸及其取代衍生物，而叶酸和某些其他叶酸则使用氧化柱后荧光衍生化系统进行测定。人们还开发了测定生物材料中叶酸多聚谷氨酰链长度分布的方法。总体而言，这些程序能够直接测定和表征叶酸化合物。
