BackgroundAn HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants.MethodsThree different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG).ResultsBoth the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column.ConclusionsThe CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

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用于测定抗氧化剂的 HPLC-CUPRAC 柱后衍生方法：多孔硅胶与核壳柱填料的性能比较

背景一种采用柱后衍生策略的 HPLC 方法，使用铜降低抗氧化能力试剂（CUPRAC 试剂）测定植物材料中的抗氧化剂，利用常规 HPLC 方法的分离能力，同时允许对抗氧化剂的检测特异性。方法三种不同的色谱柱类型，即核壳和多孔二氧化硅，包括两种化学性质不同的核壳材料（即苯基己基和 C18），以评估通过从多孔二氧化硅基质转变为核壳基质可以获得的潜在改进。茶提取物被用作评估的样品基质，特别关注儿茶素和表没食子儿茶素没食子酸酯 (EGCG)。结果与 C18 多孔硅胶柱相比，C18 和苯基-己基核壳色谱柱在分离度、峰形和保留时间方面均表现出更好的性能。在两种核壳材料中，苯基己基色谱柱与 C18 色谱柱相比具有更好的分离能力。在茶叶样品中。