Lipophilicity Measurement by Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC): A Comparison of Two Stationary Phases Based on Retention Mechanisms

✍ Scribed by Xiangli Liu; Hideji Tanaka; Aiko Yamauchi; Bernard Testa; Hiroshi Chuman

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: German
• Weight: 248 KB
• Volume: 87
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200490258

✦ Synopsis

Abstract

The mechanisms of retention of two recent stationary phases of interest in lipophilicity measurements, namely of the silica‐based Discovery‐RP‐Amide‐C16 phase and the polymer‐based ODP‐50‐4B phase, were assessed and compared. A set of 41 model solutes and drugs with well‐defined solvatochromic parameters were selected to allow a broad distribution of property spaces. The chromatographic results showed that, under the conditions of study, the lipophilicity index log k~w~ obtained with the former stationary phase was more closely related to experimental log P~oct~ values than was log k~w~ obtained with the ODP‐50‐4B phase. Linear solvation/free‐energy relationship (LSER) analyses showed that the retention mechanisms of the two stationary phases are different, retention on the Discovery‐RP‐Amide‐C16 phase and partitioning in octan‐1‐ol/H~2~O being controlled by the same balance of intermolecular forces (Van der Waals volume V~w~, H‐bond acceptor basicity β, and dipolarity/polarizability π*).