General equation for calculating the dissociation constants of polyprotic acids and bases from measured retention factors in high-performance liquid chromatography

被引：20

作者：

Jano, I ^{[1
]}

Hardcastle, JE ^{[1
]}

Zhao, K ^{[1
]}

VermillionSalsbury, R ^{[1
]}

机构：

[1] TEXAS WOMANS UNIV,DEPT CHEM & PHYS,DENTON,TX 76204

来源：

JOURNAL OF CHROMATOGRAPHY A | 1997年 / 762卷 / 1-2期

关键词：

dissociation constants; retention factors; pH effects; leukotrienes; organic bases; organic acids;

D O I：

10.1016/S0021-9673(96)00739-X

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

A general equation relating the observed retention factor to the pH of the mobile phase, the dissociation constants, and the retention factors of the different ionic species has been derived. This equation is applicable to polyprotic weak acid and base dissociation events, that is, the secondary equilibria existing in the HPLC mobile phase. It is written as: [GRAPHICS] where the k(r) values are the retention factors of the dissociated species, and K-a(r), the product of the first r-dissociation constants, K-a(r)=(i=1)Pi(r)K(a,i).x is related to the pH of the mobile phase: x=2.303 . pH. The derived equation was used to calculatethe three dissociation constants of leukotriene E(4). Also, a formula is established for calculating the range of pH values where an ionic species is most likely to be predominant in the mobile phase.

引用

页码：63 / 72

页数：10

共 6 条

[1] OPTIMIZATION OF SECONDARY CHEMICAL-EQUILIBRIA IN LIQUID-CHROMATOGRAPHY - VARIABLES INFLUENCING THE SELF-SELECTIVITY, RETENTION, AND EFFICIENCY IN ACID-BASE SYSTEMS [J].