Marchetti Nicola, Giovannini Pier Paolo, Catani Martina, Pasti Luisa, Cavazzini Alberto
Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, Italy.
Int J Anal Chem. 2019 Jan 3;2019:7535813. doi: 10.1155/2019/7535813. eCollection 2019.
The retention mechanism of four major carotenoids, two xanthophylls (i.e., lutein and zeaxanthin) and two carotenes (i.e., lycopene and -carotene), was investigated in reversed-phase liquid chromatography with the aim of thermodynamic analysis. The experimental variables considered in this study were the composition of mobile phase (MP) and the temperature. Chromatographic elutions were undertaken under linear, isocratic conditions by using a C18 stationary phase, four different MP compositions (by varying the ratio methanol/acetonitrile from 66.5/28.5 to 47.5/47.5 v/v), and column temperatures in the range 283-313 K. Traditional Van't Hoff analysis has been used to estimate changes of standard enthalpy (Δ°) and Gibbs free energy (Δ°) associated with the solute transfer from the mobile to the stationary phase at each mobile phase composition. The thermodynamic quantities have been correlated to the structure of investigated carotenoids and their interaction with the octadecyl silica stationary phase.
为了进行热力学分析，研究了四种主要类胡萝卜素（两种叶黄素，即叶黄素和玉米黄质，以及两种胡萝卜素，即番茄红素和β-胡萝卜素）在反相液相色谱中的保留机制。本研究中考虑的实验变量是流动相（MP）的组成和温度。通过使用C18固定相、四种不同的MP组成（通过将甲醇/乙腈的比例从66.5/28.5变化到47.5/47.5 v/v）以及283 - 313 K范围内的柱温，在线性等度条件下进行色谱洗脱。传统的范特霍夫分析已用于估计在每种流动相组成下与溶质从流动相转移到固定相相关的标准焓（Δ°）和吉布斯自由能（Δ°）的变化。热力学量已与所研究类胡萝卜素的结构及其与十八烷基硅胶固定相的相互作用相关联。
