Retention behavior of neutral and positively and negatively charged solutes on an immobilized-artificial-membrane (IAM) stationary phase

摘要

The retention behavior Of neutral, positively charged, and negatively charged solutes on the IAM.PC.DD2 stationary phase was investigated and compared. A set of monofunctional compounds and complex drugs (,steroids, nonsteroidal anti-inflammatory drugs, and beta-blockers) were selected for this study, i.e., neutral solutes and solutes with acidic or basic functionalities which are positively charged or negatively charged at pH 7.0. The correlation between the retention factor log k(w) at pH 7.0 on the IAM.PC.DD2 stationary phase and the partition coefficient log P,,c, or the distribution coefficient log D,,, showed that the retention mechanism depends on the charge state and structural characteristics of the compounds. The neutrals were least retained on the IAM.PC.DD2 stationary phase, and positively charged solutes were more retained than negatively charged ones. This implies that the retention of the charged solutes is controlled not only by lipophilicity but also by the electrostatic interaction with the phospholipid, with which positively charged solutes interact more strongly than negatively charged ones.