Separation of purine and pyrimidine bases by capillary zone electrophoresis with carbonate buffers

Abstract

The separation of eight purine bases was achieved by capillary electrophoresis in 16 min using a voltage of 15 kV and a 50 m M sodium carbonate–hydrogencarbonate buffer at a pH of 10. Carbonate buffers have many advantages. They are non-toxic, inexpensive, easy to prepare and provide a stable, reproducible electroosmotic flow. Equilibration time after a sodium hydroxide rinse is minimal; thus the total analysis time is shorter than when an acidic buffer is used. No additives to the buffer are required to obtain the majority of the separations of interest and uncoated capillaries can be used. A group of eight purines and the naturally occurring pyrimidines were baseline separated. The linearity correlation for adenine in an optimized separation of the bases was 0.995 over two orders of magnitude. The daily reproducibility was 0.1% and day-to-day reproducibility was 2.5%.