Preparation of [2-(Dithiocarboxyamino)ethylcarbamoylmethyl] Sephadex and Its Application to Collection of Metal Ions

Abstract

Carboxymethyl Sephadex C-25 was converted to (2-aminoethylcarbamoylmethyl)Sephadex(ED-Sephadex) by the reaction with ethylenediamine-ethanol solution at 100°C. Then, ED-Sephadex was allowed to react with carbon disulfide in triethylamine-ethanol solution at 80°C to get [2-(dithiocarboxyamino)ethylcarbamoylmethyl]Sephadex(DE-Sephadex). Mercury(II), copper(II), lead(II), cadmium(II), zinc(II), nickel(II) and manganese(II) ions could be quantitatively collected from 50 ml of 1×10^-5 mol⋅l^-1 solution of each metal salt over the pH range of 0.6∼9.9, 0.6∼9.7, 2.7∼6.0, 3.4∼9.1, 5, 0∼9.6, 5.1∼8.8 and 5.8∼8.3, respectively, by stirring with O.1 g of DE-Sephadex for 30 minat room temperature.. Collection of each metal ion from 1 mol⋅l^-1 solution of sodium nitrate, sodium chloride or sodium bromide was quantitative. Collection of mercury and copper ions from 1×10^-1 mol⋅l^-1 EDTA solution was quantitative but collection of other metal ions was incomplete. Each metal ion except for mercury ion could also be quantitatively collected from 500 ml of 1×10^-8mol⋅l^-1 metal ion solution by passing the solution through the column packed with O.3 g of DE-Sephadex or by batch method with O.1 g of DE-Sephadex, and could be recovered from the DE-Sephadex by eluting with diluted nitric acid or by dissolving the DE-Sephadex with concentrated nitric acid or a mixture of 30% hydrogen peroxide solution (O.5 ml)and 18 mol⋅l^-1 sulfuric acid (2 ml) by heating. The separation of copper ion from manganese ion was carried out as follows. Copper ion was collected from 500 ml of sample solution containing 5.00×10^-4 mmol each of both metal ions by batch method with O.1 g of DESephadex at pH 1.7 and manganese ion was collected with another fresh DE-Sephadex from the mother liquor after readjusting to pH 7.7. The separation of copper ion from other metal ions such as nickel, zinc, cadmium and lead ions was also achieved by the similar procedure.