Effect of pH on the encapsulation of the atrazine by Ã¯ÂÂ¢- cyclodextrin at 25Ã¯ÂÂ°CAuthor(s): Jamil Rima, Karin Assaker, Layal Gemayel
The encapsulation of atrazine by ï¢-cyclodextrin has been studied through UV absorption enhancement measurements in aqueous solutions at 25C. This study has been carried out at pH= 0.7, 4, 5,9 and 11. Since the pKa of the atrazine system is 1.68 at 25ï°C, the protonated (HA) of atrazine should be present at pH less than 1.68. The association constants K of ï¢-CD/atrazine have been determined at different values of pH by using linear and nonlinear regression analysis of the experimental data.The Kvalues obtained were 311 ± 15; 254 ± 15 and 150 ± 15 at the pH 5; 7.3 and 9 respectively.