Interaction of Dioxovanadium(V) Ion with Methionine at Different Ionic Strengths

The dependence on ionic strength of protonation of methionine and its complexation with dioxovanadium(V) isreported in sodium perchlorate solution as supporting electrolyte. The measurements have been performed at 25􀁻C using a combination of potentiometric and spectrophotometric techniques. The overall analysis of the presentand the previous data dealing with determination of stability constants at different ionic strengths allowed us toobtain a general equation, by which a formation constant determined at a fixed ionic strength can berecalculated, with a good approximation for another ionic strength in the range of 0.1 – 0.7 mol dm-3.