The separation of platinum and palladium by selective extraction of H_2Pt(SCN)_6 and H_2Pd(SCN)_4 using a polyTHF-impregnated filter

摘要

Platinum and palladium are known to form complexes with the thiocyanate ion in solution. The isolation and separation of both platinum and palladium as thiocyanate complexes is demonstrated by passing them through an organic-impregnated filter (OIF) prepared with polyTHF. Simultaneous extraction is performed by converting both metals into the extractable form. Sequential extraction is achieved by exploiting the difference in the rates of formation for the extractable complexes of the two metals. The extraction of both metals is rapid with quantitative recoveries of platinum with flow rates as high as 600 m min~(-1) in small samples, while recoveries from larger volume samples were considerably lower. Once extracted, the metals can be removed from the OIF by conversion to a non-extractable form with a high pH eluting solution. The rapid separation, isolation and preconcentration of both platinum and palladium from aqueous samples is demonstrated.