Synthesis and analytical properties of 3,4-dihydroxybenzaldehyde guanylhydrazone (3,4-DBGH)

Synthesis and analytical properties of 3,4-dihydroxy-benzaldehyde guanylhydrazone are described. The reagent was tested with 43 cations but only Co(II), Fe(II), Fe(III), Mo(VI), W(VI) and V(V) gave colored complexes. Spectral characteristics of the reagent are presented. Procedure for a selective a determination of Co(II), a sensitive determination of Fe(III) and determination of Mo(VI), W(VI) and V(V) in presence of large amounts of Fe(III) are reported. The method was applied for the determination (a) of Co(II) in presence of other cations at excess (b) of Fe(III) in a city drinking water sample without preconcentration and (c) of Mo(VI) in a standard steel sample.