Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buffer type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these purine derivatives. An ideal condition was found for their separation, which was 30 mmol/L sodium borate buffer (pH 9-9. 5), 10% (V/V) methanol buffer modifier and 20 kV. Under this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine, uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4. 6% (n=5) and that of migration times was in the range of 0%-3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8-10 s. In addition, alcohol, 1-propanol, 1-butanol and acetonitrile were also effective additives in the separation. However, SDS and various ###-cyclodextrin