Pyridine-2-carbaldehyde 2-hydroxybenzoylhydrazone as a selective reagent for the extraction and spectrophotometric determination of iron(II)

Abstract

Pyridine-2-carbaldehyde 2-hydroxybenzoylhydrazone reacts with iron(II) to produce a green 2:1 complex (λ_max. = 620 nm, ε= 3.64 × 10³ l mol^–1 cm^–1 in aqueous ethanolic solution, and λ_max. = 640 nm, ε= 3.67 × 10³ l mol^–1 cm^–1 in chloroform). The green complex, extracted into chloroform, has been used for the spectrophotometric determination of trace amounts of iron. The method has a high selectivity and has been applied to the determination of iron in different samples, such as industrial waste water, non-ferrous materials and minerals.