Further polarographic studies of metal complexes of Mordant red 74: the masking of interfering metals in the determination of beryllium or lead

Abstract

Mordant red 74 in its complexes with beryllium and lead is reduced at a potential 120 mV more negative than that at which the free dye is reduced. Either beryllium or lead can be determined in the presence of nickel, chromium(III) and iron(III) when these latter metals, which also give displaced waves with the dye, are masked with EDTA. Thorium(IV) interferes by forming a precipitate with the dye even in the presence of EDTA, and molybdate interferes by distorting the dye wave.