在脂肪酸水流动相中小分子在反相高效液相色谱中的保留表征  

The Characterization of Retention Behaviours of Small Molecules on Reversed-phase Liquid Chromatographic Column in Mobile Phase of n-Fatty Acid-Water System

作　　者：张养军[1] 张维平[1] 高娟[1] 耿信笃[1] 

机构地区：[1]西北大学现代分离科学研究所陕西省现代分离科学重点实验室,西安710069

出　　处：《分析化学》2001年第1期1-5,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金资助课题 !(2 9675 0 ;3 9880 0 0 3 )

摘　　要：在反相液相色谱 (RPLC)中用Snyder经验方程和计量置换保留模型 (SDM R)中的参数对溶质为脂肪醇同系物 ,流动相为脂肪酸同系物时溶质的保留行为进行了研究 ,结果表明用SDM R参数具有明显的优越性。另外 ,由于用Snyder经验公式中二参数之间的作图无法准确求得斜率 ,且其不具有明确的物理意义 ,而由SDM R二参数作图 ,不但能准确求得斜率j(与 1mol溶剂和固定相结合能有关的常数 ) ,而且j具有明确的物理意义并符合碳数规律 ,所以 ,参数j有可能用于RPLC中表征溶剂强度。由此得出 ,在RPLC中 ,对同一置换剂而言 ,随同系物溶质的Z(1mol溶剂化溶质被溶剂化固定相吸附时 ,从二者接触面释放出的置换剂分子数 )和logI(与 1mol溶质和固定相亲和势有关的常数 )值增大 ,它们的保留时间也增大 ;对同一溶质而言 ,随着在同系物置换剂中碳链的增长 ,Z和logI值的减小 ,它的保留时间也缩短。同时还可得出 ,随着同系物置换剂j值的减小 。The retention behaviours of n-aliphatic alcohols with mobile phase of n-aliphatic acids-water in reversed-phase liquid chromatography (RPLC) were studied with stoichiometric displacement model for retention (SDM-R) and Snyder's empirical equation. The results obtained showed that SDM - R was superior to Snyder's empirical equation when they were employed to characterize the retention behaviours of homologue and the solvent strength of homologous displacers. The elope, 1/q, of the plot of logK(infinity)(0) versus S has no dear physical meaning; and can not be measured accurately, while the dope, j (a constant relating to the affinity of 1 mole solvent to bonded stationary phase), of the plot of logI (a constant relating to the affinity of 1 mole of solute to beaded stationary phase) versus Z (the number of solvent molecules released from the contact surface region of 1 mole of solvated solute absorbed onto solvated bonded stationary phase) is not only determined accurately but also has a clear physical meaning and follows the rule of carbon number. Therefore, if it is possible, j can be used to characterize the solvent strength employed in RPLC. The conclusion is that with a given displacer, the retention of homologue in RPLC increases with their Z and logI increasing, if a solute is given, with the increment in carbon chain of homologous displacers, the values of Z and logI of the solute decrease and thus lead to the decrease of the solute retention, and the elution strength of a solvent becomes strong as the j value of a homologous displacer becomes small.

关 键 词：反相高效液相色谱 计量置换保留模型 保留机理 流动相 脂肪酸 醇同系物 

分 类 号：O657.7[理学—分析化学]