Effect of the net surface charge density of heptakis-6-bromo-6-deoxy-β-cyclodextrin bonded silica gels on the retention behaviors of neutral cresol isomers in HPLC was written by Nakagawa, Hiroyuki;Kitagawa, Shinya;Ohtani, Hajime. And the article was included in Analytical Sciences in 2006.Recommanded Product: 53784-83-1 This article mentions the following:
The effect of the surface charge d. of heptakis-6-bromo-6-deoxy-β-cyclodextrin (β-CD-BR) bonded silica gels, which was used as the stationary phase of a packed capillary column for HPLC, was studied concerning the retention behaviors of neutral cresol isomers. On the whole, the retention factors of the cresol isomers increased with an increase in the pH values of the mobile phase, although they were slightly smaller at pH 6.1 than at pH 4.7. A study on the retention variation using a van’t Hoff plot revealed that the increase in the retention factor (k) at a higher pH region could be mainly attributed to the increase in ΔS, while a partial decrease in k around pH 5-6 was caused by a decrease in the -ΔH/T value. However, a measurement of the electroosmotic flow velocity under various pH of the mobile phase solutions revealed that the retention variations of the neutral cresol isomers were strongly correlated with the surface charge on the packing materials. The pos. charge of secondary ammonium functional groups to bind β-CD-BR inhibit the insertion of the cresol isomers into the cavity of β-CD-BR while reducing the retention factor, whereas the neg. charge of silanol group enhanced it through a local change in the mobile phase composition In the experiment, the researchers used many compounds, for example, Heptakis(6-Bromo-6-Deoxy)-β-Cyclodextrin (cas: 53784-83-1Recommanded Product: 53784-83-1).
Heptakis(6-Bromo-6-Deoxy)-β-Cyclodextrin (cas: 53784-83-1) belongs to organobromine compounds. Most organobromine compounds, like most organohalide compounds, are relatively nonpolar. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.Recommanded Product: 53784-83-1
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary