Kinetic Determination of Lanthanum(III) by the Catalytic Effect on the Oxidation of Fluorescent Safranine Dyes with Potassium Bromate.

Two simple and sensitive kinetic-fluorometric methods have been developed for the determination of lanthanum(III): fluorescence quenching generated by the oxidation of safranine T or phenosafranine with potassium bromate in an acetate buffer solution. The rate of the oxidation reaction is significantly accelerated after adding lanthanum(III). A good linearity between the relative fluorescence intensity and lanthanum(III) is observed in the range of both 0.