Popis: |
The chromogenic reactions of semi-glycinethymol blue have been studied spectrophotometrically and by complementary tristimulus colorimetry. The separation of the dye from a commercial product of glycinethymol blue is described. The five dissociation constants were determined; the means of the pKa (HiI) values for i= 5, 4, 3, etc. are —1.5, 0.3, 1.5, 7.5, and 12.7, respectively. Colour reactions with some metal ions are reported; the reaction with copper(II) is suggested for the determination of the composition of commercial samples of glycinethymol blue. |