کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1207294 | 1493724 | 2008 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrostatic interactions and ionization effect in immobilized artificial membrane retention
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
The present study is a continuation of our efforts to investigate the effect of electrostatic interactions and ionization on immobilized artificial membrane (IAM) retention. The previous set of neutral and basic drugs was extended to include acids and ampholytes and analogous buffer conditions in the mobile phase were used, namely morpholinepropanesulfonic acid and phosphate buffer saline, adjusted at pH 7.4. The important contribution of electrostatic forces in IAM retention of positively charged species was further justified by the results of the present study, while analogous electrostatic interactions for ionized acidic drugs were not found to affect significantly the affinity for the IAM stationary phase. The critical role of shielding or exposure of the charged centers on the IAM surface, as a result of the effect of the aqueous component of the mobile phase, was evaluated by the use of water instead of buffer for a number of drugs. Measurements at pH 5.0 demonstrated the effect of ionization in IAM retention despite the partial compensation by electrostatic interactions in the case of protonated basic drugs. Silanophilic interactions were also found to play a potential role as secondary interactions in IAM retention. IAM chromatographic indices were compared to octanol-water distribution coefficients and the corresponding relationships established. Finally, solvation analysis was applied in the aim to gain insight in the balance of forces between IAM retention and octanol-water partitioning. The results showed that apart from electrostatic interactions, there is no significant differentiation between the two systems.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1187, Issues 1â2, 11 April 2008, Pages 67-78
Journal: Journal of Chromatography A - Volume 1187, Issues 1â2, 11 April 2008, Pages 67-78
نویسندگان
Demetris Vrakas, Costas Giaginis, Anna Tsantili-Kakoulidou,