Extraction of palladium from nitric acid medium and its spectrophotometric determination using arsenazo III

Summary Di-octyl sulphoxide in xylene was successfully employed for extracting palladium from 0.5 to 1.5 mol/l nitric acid medium. The extracted species was found to be Pd(NO₃)₂·2DOSO. The palladium was back extracted into a mixture of 2 mol/l sodium carbonate and 0.05 mol/l ammonia. The recovery was found to be quantitative. A spectrophotometric method using Arsenazo III was developed in nitric acid medium for the determination of palladium. The colour development was found to be maximum in the acid range of 2.5 to 5 mol/l. Beer's law was found to be obeyed in 1 to 100 g range of palladium. The molar extinction coefficient was found to be 2.26×10⁴ l/mol/cm. The RSD obtained at 16 g of palladium was 5%.