Keywords Two-phase titration;tertiary synergistic extraction;europium;pyrazo lone;diamyl sulphoxide;tributyl phosphoxide;the stability constant of the complex.;

• 两相滴定法;三元协同萃取;铕;吡唑啉酮;二戊基亚砜;三丁基氧化磷;萃合物的稳定常数;