Picolinaldehyde nicotinoylhydrazone for trace level separation and spectrophotometric determination of copper(II)

Abstract

A sensitive method is proposed for extraction and spectrophotometric determination of copper(II) at trace levels using picolinaldehyde nicotinoylhydrazone (PANH) as an analytical reagent. The yellow coloured PANH-Cu(II) complex, extracted into chloroform in the <i>p</i>H range 8.5-10.5, shows maximum absorbance at 380 nm. Beer's law is obeyed over the range 10-300 ng ml^-1 of copper(II). The molar absorptivity and the Sandell's sensitivity for copper(II )-PANH system has been found to be 5.8×10⁴ l mol ^-1 em^-1 and 1.1 ng cm^-2 respectively. The extracted species has a 1:2 (metal:ligand) stoichiometry. The proposed method is highly sensitive, selective, simple and rapid , and has been applied for accurate determination of copper in alloys and pharmaceutical samples.