University of Western Sydney (UWS), Australian Centre for Research on Separation Science (ACROSS), School of Science and Health, Penrith, NSW 2751, Australia.
J Chromatogr A. 2013 May 24;1291:179-86. doi: 10.1016/j.chroma.2013.03.041. Epub 2013 Mar 26.
Carbohydrates partially liberated by acid hydrolysis of plant fiber can be separated by hydrophilic interaction liquid chromatography (HILIC), ligand-exchange liquid chromatography or other forms of LC with ion-exchange columns. However, the robust hydrogen-exchange columns show co-elution of galactose, xylose and mannose. Free solution capillary electrophoresis (CE) can be used without derivatization at pH 12.6 and was found to provide a higher resolution of galactose and xylose than common LC with no sample pre-treatment required, other than dilution, within 26min. CE was able to provide resolution higher than 0.79 for all separated carbohydrates, and the RSDs of determined concentrations lower than 10% for concentrations above 1.3gL(-1). A quantitative comparison between CE and HPLC revealed that up to 22% more carbohydrates are quantified with CE. Direct UV detection in CE of mono- and disaccharides is unexpectedly possible at 270nm. NMR analysis shows that alkaline degradation is too slow to explain this detection. This CE detection sensitivity is increased by the electric field and our CE and NMR analyses are consistent with a photo-oxidation process.
通过植物纤维酸水解部分释放的碳水化合物可以通过亲水作用液相色谱（HILIC）、配体交换液相色谱或其他形式的带有离子交换柱的 LC 进行分离。然而，强氢键交换柱显示出半乳糖、木糖和甘露糖的共洗脱。在 pH 值为 12.6 时，无需衍生化即可使用游离溶液毛细管电泳（CE），并且发现与没有样品预处理的常见 LC 相比，在 26min 内可以提供更高的半乳糖和木糖分辨率，无需稀释，除了稀释。CE 能够为所有分离的碳水化合物提供高于 0.79 的分辨率，并且对于浓度高于 1.3gL(-1)的浓度，确定浓度的 RSD 低于 10%。CE 与 HPLC 之间的定量比较表明，CE 可以定量多达 22%的碳水化合物。在 CE 中，意想不到的是可以在 270nm 处直接检测单糖和二糖。NMR 分析表明，碱性降解太慢，无法解释这种检测。CE 的这种检测灵敏度可以通过电场提高，我们的 CE 和 NMR 分析与光氧化过程一致。
