Partition chromatographic separation of adenine and guanine.

In the course of an investigation into the metabolic pathways of nucleotide purines by means of tracer elements, it became necessary to prepare from biological sources pure specimens of adenine and guanine in sticient quantities for analyses in the mass spectrometer. In general, for preparative purposes, use has been made of the insolubility of adenine and guanine under certain strictly specified conditions. For small quantities of purines, however, these methods are unsatisfactory because of the difficulties in maintaining the specified conditions in small volumes. The employment of the liquid-liquid distribution principle in the form of partition chromatography seemed more promising as a separatory procedure for small amounts of purine, especially since Vischer and Chargaff (1) have shown that it is possible to separate adenine and guanine on paper strip chromatograms in the system quinoline-collidine-water. After the conclusion of our work a paper by Tinker and Brown (2) was brought to our attention. They employed the system butanol-1 M phosphate buffer, pH 6.5, for the separation of the purines in the Craig apparatus. In our work partition chromatography on starch (3, 4) has effected the desired separation of adenine and guanine.