Synthesis of Bis(D-glucose)oxalyldihydrazone for Trace Copper Determination

Abstract

A new style water-soluble hydrazone, bis(D-glucose)oxalyldihydrazone (BGOH), has been synthesized by introducing glucose molecules into the hydrazone molecule, its chromogenic property and reactivity with metal ions investigated and it used for the spectrophotometry determination of copper. BGOH reacts with copper(ll) to form a blue 1:1 complex with absorption maxima at 311 and 608 nm in neutral to weakly alkaline media. On this basis, a simple and selective spectrophotometric method for the determination of copper has been proposed. The apparent molar absorptivity of the complex at 608 nm is 1.55×10⁴ I mol^-1 cm^-1. The proton dissociation constant of the ligand and the formation constant of its copper(ll) complex determined spec-trophotometrically are 10^-10.21 and 10^-5.49, respectively, at 25°C and at an ionic strength of 0.1. Sensitization of the method by employing analogue derivative spectrophotometry is also described.