Determination of a Trace Amount of Copper, Lead, Cadmium and Zinc in Water by Solvent Extraction and Square Wave Polarography

摘要

The following new techniques have been developed: (A); To a 500ml of sample water, it was adjusted pH 10 with ammonia-anmonium citrate, added 10ml of 1% sodium diethyldithiocarbamate and extracted three times with 10ml of CHCl3. The extract was shaken with 10ml of 0.05N HCl - 4 ?? 10-4 M HgCl2. The aqueous solution was added 2ml of 2N KCl and washed two times with 10ml of pure CHCl3, and then recorded square wave polarograms. (B); To a 500ml of sample water adjusted pH 10 with ammonia-ammonium citrate, it was added 2ml of 1% 8-hydroxyquinoline and extracted three times with 10ml CHCl3. The separated CHCl3 phase was shaken with 10ml of 0.2 N HCl. The aqueous solution was recorded polarograms directly. These methods can be used for determination of the ppb order of metal in water with an error of ??10%. The method (B) can not be used for the determination of zinc on account of the free 8-hydroxyquinoline.