X-ray fluorescence determination of cobalt on polyurethane foam

Although the extraction and preconcentration of several species by polyurethane foam have been reported, very few methods have included a direct determination of the component on the polymer. Cobalt thiocyanate is highly extractable by polyether polyurethane from solutions of 3M NH(4)Cl and 1M NH(4)SCN. After extraction of the cobalt the foam discs can be analysed by X-ray fluorescence, which gives a linear response for samples treated identically. Cobalt at levels as low as 0.05 ppm can be quantitatively extracted and cobalt determined in the presence of several other metal ions.