Capillary electrophoresis is an analytic separation technique, of which advantage over other separation techniques is that it requires smaller quantities of samples and solvents, when compared with some other separation techniques. Separation occurs under the influence of an electric field inside the capillary, filled with a buffer solution. The basic separation principle is based on classical electrophoresis and the electroosmotic flow. With the phrase electrophoresis we define the migration of ions under the influence of the electric field, meanwhile the term electroosmotic flow defines the movement of an entire electrolyte solution towards the cathode due to partially deprotonated silanol groups on the capillary wall and the consequent excess of cations in the buffer solution. Using electrophoresis, we can separate particles carrying different charges, as they significantly affect electrophoretic mobilities of them, and we can also separate particles of the same charge if they differ in size or shape.
In this work, I wanted to determine the electrophoretic mobility of the fullerenehexamalonate ion with the use of capillary electrophoresis, which can be accomplished through complete ionization of fullerenehexamalonic acid Th-C66(COOH)12. I have calculated its electrophoretic mobility from the measured migration times for the analysed ion and acetone, applied voltage on the capillary, and the length of the capillary. Because fullerenehexamalonic acid is sensitive to partial decarboxylation, two peaks were observed in recorded electropherograms: the first peak belonged to non-degraded acid Th-C66(COOH)12, and the second one probably occurred due to the presence of once decarboxylated fullerenehexamalonic acid, C66H(COOH)11. I varied the conditions of separation, I acidified the sample and heated it to higher temperatures, in order to provoke its accelerated partial decarboxylation. This purposeful decarboxylation also reflected in the electropherograms: several new peaks were observed due to degradation of the compound when more than one CO2 molecule was released from the original molecule.
I also wanted to determine the repeatability of our measurements of electrophoretic mobilities, how electrophoretic mobility is affected by the buffer concentration and voltage on the capillary, the separation efficiency, resolution and the hydrodynamic radius of the fullerenehexamalonate ion.
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