Reversed phase partition chromatographic separation of divalent copper with N-n-octylaniline on silica gel

A novel separation method was developed for the extraction and chromatographic separation of copper(II). The quantative extraction of 25.0–125.0 μg copper(II) has been observed from 0.05 to 0.25 mol/L of ascorbic acid at pH 9.0–12.0 with 0.087 mol/L N-n-octylaniline (liquid anion exchanger) coated on silica gel at a flow rate of 1.0 ml/min. The extracted metal ion has been recovered by eluting with 25.0 ml of 1.0 mol/L hydrochloric acid and determined spectrophotometrically by rubeanic acid method. The various influencing parameters viz. acid concentrations, reagent concentration, eluates effect of pH, and effect of flow rate on extraction were studied. The method is free from large number of interferences from cations and anions. A scheme for mutual separation of copper(II), gold(III) and bismuth(III) has been developed. Copper(II) has been separated from ayurvedic (Herbal) medicine and synthetic mixtures corresponding to alloy. The log–log plot of N-n-octylaniline concentration versus the distribution coefficient indicates that the probable extracted species is [RR′NH2+)3·Cu(C6H7O6)53-]org.