Extraction of Traces of Copper as Tetra-Butylammonium Tetrathiocyanato Copper (II) and Its Spectrophotometric Determination Using Eriochrome Black T

Abstract

An extraction-spectrophotometric method for the determination of traces of copper (II) is described. The method is based on the quantitative extraction of copper as tetrabutylammonium tetrathiocyanato copper (II) into methyl isobutyl ketone, followed by spectrophotometric determination, using eriochrome black T as a metallochromic indicator. The red-violet mixed complex of copper absorbs at lmax = 570 nm with a molar absorptivity of 4.4´104 Lmol-1cm-1. The sandell's sensitivity for 0.001 absorbance unit is 1.4 ngcm-2. The method is simple, sensitive and free of interferences from many anion and cations.

Keywords

• copper
• determination
• thiocyanate
• eriochrome black t
• extraction
• spectrophotometry