1. Since under the same conditions a 3∶2 precipitate is obtained with adenine it is also possible to determine mixtures from 8-bromoadenine, Br− and adenine potentiometrically.

2. Lead tetraacetate was allowed to react with the sample in dilute acetic acid and in the presence of alkali acetate. The excess reagent was titrated after a specified tune potentiometrically with standard hydro-quinone solution.