LONG-CHAIN ALKYL AND CHOLINE SUBSTITUTED XANTHATES AS EXTRACTANTS FORCADMIUM(II)

The complexes of cadmium(II) with the xanthate anions ROCS2- (R = C2H5 , 1-C4H9, 1-C8H17, 1-C18H37 and CH2CH2N(CH3)3+) have been synthesized. The stoichiometry of the complexes in aqueous solution has been confi rmed as 1:2 for cadmium: xanthate by the mole ratio method. The aqueou s solubility of the complexes decreases with increasing alkyl chain le ngth of R, but increases in the presence of the cetyltrimethylammonium and dodecylsulphate detergent ions. The choline-substituted xanthate ligand can be used for the electrokinetic extraction of cadmium ions f rom soils where its efficiency is approximately 10% of that of EDTA. T he addition of the ionic detergents cetyltrimethylammonium bromide (CE TAB), cetyltrimethylammonium-p-toluenesulphonate (CETATS) or sodium do decylsulphate (SDS) increases the aqueous solubility of the cadmium xa nthates by some 20%.