从pH 3.0的水溶液中,在较大量的硫酸铵存在下,Pt(Ⅳ)以Pt(SCN)2-6形式定量萃取入乙醇中.萃取体系中各试剂的适宜用量为硫氰酸铵溶液20 g·L-1,硫酸铵溶液300 g·L-1,乙醇0.30 mL·mL-1,按此条件可达到Pt(Ⅳ)与适量的Ni(Ⅱ),Cr(Ⅲ),Co(Ⅱ),Fe(Ⅱ),Mn(Ⅱ),Al(Ⅲ),Rh(Ⅲ)等离子分离.此方法已用于催化剂Ni-Pt/Al2O3试样分析中作为分离手段.对一件上述催化剂试样进行5次测定,测得铂的平均结果为w(Pt) 0.104%,RSD为1.7%.

It was found that platinum(Ⅳ) was quantitatively extracted into ethanol in the form of Pt(SCN)2-6 in the presence of relatively large amount of ammonium sulfate from a solution of pH 3.0.The optimum amounts of the reagent present in the extraction system were as follows: NH4SCN 20 g·L-1,(NH4)2SO4 300 g·L-1 ethanol 0.30 mL·mL-1.Under these conditions,Pt(Ⅳ) was effectively separated from appropriate amounts of Ni(Ⅱ),Cr(Ⅲ),Co(Ⅱ),Fe(Ⅱ),Mn(Ⅱ),Al(Ⅲ) and Rh(Ⅲ).This method has been applied to the analysis of Ni-Pt/Al2O3 catalyst as a separation process,and 5 determinations of Pt(Ⅳ) in a catalyst sample were performed giving an average result of w(Pt) 0.104% with RSD of 1.7%.