姜黄素键合硅胶固定相高效液相色谱分离取代芳香酸类化合物

The Separation of Aromatic Carboxylic Acids on Curcumin Bonded Silica Gel Stationary Phase by HPLC

研究了13种取代芳香酸类化合物在姜黄素键合硅胶固定相(CCSP)上的色谱行为,考察了甲醇含量、流动相pH值对CCSP分离取代芳香酸类化合物的影响,探讨了该固定相对芳香酸类化合物的色谱保留机理,并应用于实际样品复方水杨酸搽剂的分离分析。结果表明,在不同含量的甲醇-0.02 mol.L-1NaH2PO4(pH=2.5)流动相体系中,三组芳香酸标准混合样和实际样品中四种主要成分在CCSP上实现基线分离。与ODS柱相比,在相同条件下,CCSP对这类酸性化合物具有较高的选择性,且对13种取代芳香酸类化合物的洗脱顺序与ODS具有显著差异,其中5种溶质在CCSP上的保留强于ODS,这说明不同保留机理的存在。研究表明,CCSP具有典型的反相色谱特征,但疏水性较ODS弱;除疏水作用外,n-π和π-π作用、氢键作用、电荷转移作用、偶极-偶极作用对分离也有贡献。CCSP对极性、电离性物质如水杨酸、对硝基苯甲酸、3,4,5-三羟基苯甲酸、邻苯二甲酸和邻溴苯甲酸等具有较强的保留;由于CCSP较弱的疏水性和多种分离机制,邻氯苯甲酸和苯甲酸在CCSP上的保留不会像在ODS上那么强,且分离度明显优于ODS。

The high-performance liquid chromatographic behavior of thirteen aromatic carboxylic acids was studied on a curcumin bonded silica gel stationaryphase （CCSP）. The comparative study of the separation of these compounds was done by using ODS as reference under the same chromatographic conditions. The influence of mobile phase variables such as methanol content and pH on the retention behavior was investigated. The retention mechanism of the above solutes on CCSP was also discussed. Meanwhile, CCSP was employed for separation of compound salicylic acid liniment sample. The results showed that baseline separation of three series of aromatic carboxylic acids mixed standards and four main components in the sample were achieved on CCSP using different content of methanol-0.02 mol- L^- 1Nail2 PO4 （pH=2.5） as mobile phases. CCSP behaved as a reversed-phase packing and its separation selectivity for aromatic carboxylic acids was much better than that of ODS, what＇s more, the different elution orders of some solutes were observed on both CCSP and ODS. Five of solutes exhibited stronger affinities to CCSP. Based on the chromatographic data, it could be concluded that the synergistic interactions existed on CCSP, such as hydrophobic interaction, n-π and π-π interaction, hydrogen bonding interaction, the charge transfer interaction, and dipole-dipole interaction. The CCSP containing curcumin ligand has two advantages over ODS. On one hand, the polar and ionized analytes, such as salicylic acid, p-nitrobenzoic acid, 3,4,5-trihydroxybenzoic acid, phthalic acid and o-bromobenzoic acid showed stronger affinities to CCSP because of various synergistic mechanisms. On the other hand, the retention of benzoic acid and o-chlorobenzoic acid became shorter and they were much better separated on CCSP with weaker hydrophobicity and various retention mechanisms in comparison with ODS. CCSP has a promising application in the simple and effective separation of polar aromatic carboxylic acids.