Separation of Platinum(Ⅳ) by Floatation with the System CTMAB-KBr-NaNO₃

In a clark-Lubs buffer medium of pH 3.0,platinum(Ⅳ) was quantitatively separated by floatation as PtBr2-6·2CTMAB+ from testing solution containing 0.59 mol·L-1 of NaNO3,5.0×10-3mol·L-1 of KBr and 3.0×10-3mol·L-1 of CTMAB. As a total volume of 10 mL was taken in the floatation process,0.5 mL of 0.1 mol·L-1 KBr solution,3 mL of 0.01 mol·L-1 CTMAB solution and 0.5 g of NaNO3 were added. As shown by experimental results 100 μg of Pt(Ⅳ) were effectively separated from as much as 1 000 μg of Cr(Ⅲ),Mn(Ⅱ),Al(Ⅲ),Ni(Ⅱ),Ga(Ⅲ),Fe(Ⅱ) and Zn(Ⅱ),achieving to a floatation rate of about 100%. The proposed method was applied to the analysis of sample of Ni-Pt/Al2O3 catalyst with known Pt content (w) 0.102%. Result of average content of platinum found by this method was (w) 0.099% and value of RSD′s (n=7) calculated from the analytical data was 2.2%.