The dissociation constants of alizarin fluorine blue.

Dissociation constants for the analytical reagent alizarin fluorine blue (3-aminomethylalizarin-N N-diacetic acid) have been determined by potentiometric titration at ionic strength 0.1, and are k(1) = 1.28 +/- 0.30 x 10(-5); k(2) = 2.82 +/- 0.24 x 10(-8); k(3) = 3.72 +/- 0.19 x 10(-11); k(4) = 6.39 +/- 0.12 x 10(-12).