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

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 pH 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 5.8X10(4) I mol(-1) cm(-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.