Chronopotentiometry of Flavinmononeucleotide (FMN).

I. Adsorption Wave

Abstract

In D.C. polarographic studies on the electrode processes of riboflavin since Brdicka1 5), it has been considered that only leucoform (reductant) of riboflavin is adsorbed on the mercury electrode. But recently Senda et a16). and Breyer et a17). have presented the evidence of the adsorption of both riboflavin (oxidant) and leucoform on the electrode in A.C, polarographic studies. Lorenz8) proposed theoretical equations on the adsorption processes in electrolysis at controlled current density, which are applicable to any type of adsorptions accompanied by electrolysis of the adsorbed species.
The author reports experimental results in chronopotentiometric study on the adsorption wave of FMN mainly in the concentration range of 10^-6-10^-5 mol/l in which the surface of mercury electrode is considered to be unsaturated with adsorbed FMN molecules according to the knowledge in polarography.
A noticiable feature of the results in the present study is that constancy of i₀τ values (i₀, current density; τ, transition time) was observed in a given concentration range and at current density chosen in a certain range and consequently the value of i₀τ/nF corresponds to the density of adsorbed species on the electrode surface at potential before applying current pulse.