In this study, a rapid (less than 10 min) analytical method by reverse-phase supercritical fluid chromatography was developed with an isocratic mobile phase, enabling the separation of 11 compounds, chlorophyll a and b, pheophytin a and numerous allomers or epimers. This method was used to examine the stability of chlorophyll pigments of plant extracts obtained with various extraction methods including microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), pressurized liquid extraction (PLE) and ultrasound-assisted extraction (UAE), with ethanol as solvent or modifier. The effect of storage was studied for both liquid and dried extracts. Irrespective of the extraction method, the evaporation of the extracts induced partial degradation of the chlorophyll pigments. It was found that liquid extracts could be stored at 4 °C for 3 weeks without a dramatic change in allomer forms of chlorophylls. However, during this storage period, epimerization appears to be important, leading to a significant decrease in the chlorophyll b native form. Graphical abstract.

中文翻译：

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超临界流体色谱法评估富含叶绿素的提取物的提取和稳定性。

在这项研究中，采用等度流动相开发了一种快速（少于10分钟）反相超临界液相色谱分析方法，能够分离11种化合物，叶绿素a和b，脱镁叶绿素a和许多同分异构体或差向异构体。该方法用于检查通过多种提取方法获得的植物提取物的叶绿素色素的稳定性，包括微波辅助提取（MAE），超临界流体提取（SFE），加压液体提取（PLE）和超声辅助提取（UAE），用乙醇作为溶剂或改性剂。研究了液体提取物和干燥提取物的贮藏效果。不论提取方法如何，提取物的蒸发都会导致叶绿素色素部分降解。发现液体提取物可以在4°C下保存3周，而叶绿素的异构体形式没有显着变化。但是，在此存储期间，差向异构似乎很重要，从而导致叶绿素b天然形式的显着减少。图形概要。