Solid-Phase Extraction of Copper with Lead 4-Benzylpiperidinedithiocarbamate on Microcrystalline Naphthalene and Its Spectrophotometric Determination

Abstract

Using lead 4-benzylpiperidinedithiocarbamate complex (Pb(4-BPDC)<inf>2</inf>), a solid-phase extraction method was developed for pre-concentration and spectrophotometric determination of copper in water samples. In this method, copper in large volume liquid phase quantitatively replaces lead on colorless Pb(4-BPDC)<inf>2</inf> complex and naphthalene solid phase mixture forming Cu-4-benzylpiperidinedithiocarbamate complex (Cu(4-BPDC)<inf>2</inf>). The solid phase containing colored Cu(4-BPDC)<inf>2</inf> is dissolved in chloroform and its absorbance is measured at 437 nm against the reagent blank. The range of linearity is 0.4 -10 μgml-1 of copper in chloroform, the molar absorptivity of the complex determined from the linear portion of Beer's law plot is 8.197×103 lmol-1cm-1 and the sensitivity is 0.0013 μgcm-2 for an absorbance of 0.001.