کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1204664 | 965162 | 2011 | 5 صفحه PDF | دانلود رایگان |
The chromatographic behavior of native titania was investigated in aqueous normal phase chromatography using a set of N-methylated xanthines as polar test solutes. In agreement with a hydrophilic interaction on a polar bed, the retention of xanthine models increased mainly along their molecular polarity. Adsorption of these molecules on the hydrated surface of titania prevailed as a retention mechanism for low water contents in the mobile phase. Several N-methylated xanthines could be easily discriminated along the number and position of their methyl groups while the nitrogen atom at position 3 was found deeply involved in the retention on titania. To get further insights on the interactions occurring on the surface of titania, the retention of xanthine derivatives based on ligand-exchange was evaluated as a function of the buffer concentration and type. The separation efficiency of native titania for the set of N-methylated xanthines was comparable to that observed on zirconia but lower than that obtained on native silica due to mixed-mode interactions. However, titania exhibited a superior ability to recognize several isomeric positions of xanthine derivatives in comparison to zirconia and silica.
Journal: Journal of Chromatography A - Volume 1218, Issue 5, 4 February 2011, Pages 721–725