PMBP 已用于连续测定稀土、钍;稀土、锚、钍、锆(铪)。也曾用于分离测定钪,但钍有严重干扰。本文拟定以铜试剂-三氯甲烷萃取除去铁、锰、铜、镍及铋等干扰元素后,用 PMBP-TBP 协同萃取,再分别用不同浓度的盐酸连续反萃取,以偶氮胂Ⅲ显色测定稀土和钍;以甲基百里酚蓝显色测定钪。方法简便、快速,可用于组成复杂的试样中含量为0.005～2.0%的稀土、钪和钍的测定。 PMBP has been used for the continuous determination of rare earth, thorium; rare earth, anchor, thorium, zirconium (hafnium). Scandium has also been used for the separation and determination, but thorium has a serious interference. In this paper, the interference elements such as iron, manganese, copper, nickel and bismuth were extracted by copper reagent-trichloromethane, and then were extracted by PMBP-TBP and then repeatedly stripped with different concentrations of hydrochloric acid. Determination of rare earth and thorium; methyl thymol blue color determination of scandium. The method is simple and rapid, and can be used for the determination of rare earth, scandium and thorium with the contents of 0.005-2.0% in complex samples.