40r 



•30 



T^ZO 



O 10 



ADENINE 



CYTOSINE 



URACIL 



THYMINE 



GUANINE 



100 200 300 400 500 600 700 800 

 VOLUME OF NH.OH-NH.GL BUFFER IN ml 



Fig. 3. Separation of purine and pyrimidine bases by anion exchange in a chloride 

 system. ^^ 



Exchanger: Dowex-l-Cl~, ca. 300 mesh, 8.5 cm. X 0.74 cm. 2. 



Solution: 0.2 M NH4OH + 0.025 M NH4CI, pH 10.6 (at a, pH -^ 10.0, CI" — 0.1 



M); 0.25 ml./min. 



Sorbed material: 1-2 mg. of each base in eluting buffer. 



Influent 



pH- 



Rrmk; Acid + NH4OH buffers, formate ion« 0.01 M 



lllo 



it 25- 



•fii 



200 600 



■^ N 



ml . through column 



Fig. 4. Separation of bases, ribosides, and nucleotides by anion exchange in a 

 formate system.'' 



Exchanger: Dowex-1-formate, 13 cm. X 0.74 cm.''. 

 Solutions: as shown, 0.5 ml./min. 



Sorbed material : as shown. Substances in brackets were not included in this sepa- 

 ration but were examined separately. The dotted line indicates the method of 

 identification by spectrophotometric absorption ratios. 



220 



