Abstract
The sample of high purity tellurium is dissolved in aqua regia. Arsenic and tin are separated as their bromides by distillation from perchloric acid solution, and arsenic in the distillate is reduced to As (III) from As(V) by KI and Na2S2O5. It is followed by the extraction with chloroform solution of diethylammonium diethyldithiocarbamate. After the organic layer is treated with strong acids to destroy organic matters, arsenic is determined spectrophotometrically by molybdenum-blue method.
As tin remains as Sn(IV) in the aqueous layer, it is reduced to Sn(II) by thioglycolic acid and extracted with diethyldithiocarbamate-chloroform solution. The organic layer is treated with acids to decompose organic matters and tin is determined spectrophotometrically by phenylfluorone method. Micro-amounts of arsenic and tin as low as 0.5 ppm each are estimated by the proposed method.
