以溶质计量置换保留模型(SDM-R)为依据，通过研究3种正链醇同系物溶剂置换剂对14种正 链醇同系物溶质 色谱保留行为的影响，发现计量置换参数Z(对应1 mol溶质被吸附时从溶质与固定相接 触处释放 出的溶剂的总摩尔数)、lg I(与1 mol溶质对固定相亲和势有关的常数)和j（与1 m ol溶剂对固定相亲 和势有关的常数）均随着同系物置换剂相对分子质量的增大而减小，并呈现出线性变化，表 明溶剂 强度与溶剂分子的大小有关，分子愈大，溶剂洗脱能力愈强，并遵循同系物规律。此外，还 得出了j作为溶剂强度参数最为可靠及准确的结论，从一个新的角度揭示了液相色谱中 同系物规律。与Snyder经验公式中对应的3个参数比较，发现那3个参数的这种规律展示得不 明显。
关键词：反相高效液相色谱；计量置换保留模型；同系物；置换剂；保留机 理
中图分类号：O657　　　文献标识码：A
文章编号：1000-8713(2000)06-0475-05

Study on the Rule of Solvent Strength in Reversed-Phase
Liquid Chromatography

ZHANG Wei-ping, GUO Hong, GAO Juan, GENG Xin-du
(The Key Laboratory of Modern Separation Science of Shaanxi Provi nce,Institute of Modern Separation Science, Northwest University, Xi′an 71006 9, China)

Abstract:Based on the physical meanings of Z(total moles of the released solven t at the contact region between solute and stationary phase), and j(the slop e of the linear plot of lg　I versus Z, a constant relating to the affinity of organic solvent to the stationary phase) of stoichiometric displacement model for reten tion (SDM-R) of solute in liquid chromatography(LC), both Z and j could be emplo yed to characterize solvents, therefore, Z value only can be used as a ch aracterization parameter for fixed solute and stationary phase. However , the parameter j is independent of solutes. As long as phase is given, j can be employed as a new characterization parameter of organic solvent strength in LC. With the homologues of methanol, ethanol and n-propanol as organic solvent s in mob ile phase and n-alkylalcohols as solutes, both the SDM-R and Snyder's emp irical equation were tested, and compared with the corresponding parameters obta ined from S nyder's empirical equation. With S ［the slope of the linear plot of lg　 k′ (k′ is capac ity factor) vs φ(volume fraction of organic solvent in mobile phase )］ and lg　kw0 (the intercept of this plot), it was found that the two linear plots with the SDM-R, lg　k′ vs the composition of mobile phase and lg　I vs Z were better than the corresponding plots with Snyder's empirical equation.The results indicate that Z, lg　I and j decrease with the increas e in the molecular size of the organic solvent of the homologue. This fact indicat e s that the solvent strength in LC depends on the size of solvent molecules. And the greater the solvent molecules, the stronger the solvent strength is. Furt h ermore the solvent strength was found to follow homologous rule. The j val ue ma y become a new parameter for the characterization of organic solvent strength in LC.
Key words:reversed-phase high performance liquid chromatograp hy; stoichiometric displacement model for retention; homologue; displacer; reten tion mechanism?

基金项目：国家自然科学基金资助项目(2967017，39880003)
作者简介：张维平(1964-)，女，讲师。

参考文献

［1］Valko R, Snyder L R, Glajch J L. J Chromatogr, 1993,656:501 -520
［2］Schoenmaker P J, Tijsen R. J Chromatogr, 1993,656:521-535
［3］Johnson B P, Khaledi M G, Dorsey J G. Anal Chem, 1986,58:2 354-2 365
［4］Geng X D, Regnier F E. J Chromatogr,1985,332:147-168
［5］Snyder L R, Dolan J W, Gant J R. J Chromatogr,1979,165:3-30
［6］Snyder L R, Kirland J J. Translated by GAO Chao，CHEN Xin- min，GAO Hong（高 潮,陈新民,高 虹译). Introduction to modern liquid chromatog raphy（现代液相色谱法导论）. 2nd ed（第2版）. Beijing：Chemical Industry Press （北京:化学工业出版社），1988.235-239
［7］Snyder L R, Kirland J J. Translated by GAO Chao，CHEN Xin- min，GAO Hong（高 潮,陈新民,高 虹译). Introduction to modern liquid chromatog raphy（现代液相色谱法导论）. 2nd ed（第2版）. Beijing：Chemical Industry Press （北京:化学工业出版社），1988.350-354
［8］SONG Zheng-hua，GENG Xin-du(宋正华,耿信笃). Acta Chimica Sinica(化学 学报)，1990，48：237-241
［9］Kunitaini M, Johnson D, Snyder L R. J Chromatogr, 1986,371:313 -333
［10］Gao J, Yu Q, Geng X D. J Liq Chrom & Technol, 2000,23:1 267-1 279
［11］Snyder L R, Quarry M A, Glajch J L. Chromatogr-phia,1987,24:33-44
［12］Kaibara A, Hirose M, Nakagawa T. Chromatogr-phia, 1990,29:551-556
［13］GENG Xin-du(耿信笃). Science in China,Series B(中国科学\5B辑），199 5,38:1 409-1 416