【摘要】 提出了k系数双波长标准加入分光光度法同时测定La和Pr的新方法.以邻苯二酚紫(PV)为显色示剂,表面活性剂溴化十六烷基吡啶(CPB)为增溶剂,于pH=8.27的盐酸-硼砂缓冲溶液中,PV和CPB与Pr和La分别形成蓝色三元配合物,其最大吸收波长均在670 nm处.在试验条件下,La和Pr的均在0～20!g/mL呈良好的线性关系,表观摩尔吸光系数分别为7.06×104 L(/mol.cm)和4.28×104 L(/mol.cm).该方法选择670 nm为测定波长,730 nm为参比波长,按系数倍率双波长标准加入法原理,对Pr,La混合体系的同时测定进行了研究.并进行了标准混合样的测定,当合成样中mPr∶mLa=1∶1～1∶6时,回收率为95%～110%,结果满意.更多还原

【Abstract】 A new method for the simultaneous spectrophotometric determination of La and Pr is proposed.In the buffer solution of Na2B4O7-HCI,La and Pr react with pyrocatechol violet and cetyl pyridine bromide(CPB) and form a blue ternary complexs of which apparent mole absorbance index is 7.06×104 L/(mol·cm) and 4.28×104 L/(mol·cm),Beer’s Law are obeyed in the range of concentration of La and Pr from 0 to 20 μg/l0 mL.The absorbances of complex solution were measured at wavelength of 670 nm and 730 nm,respectively,and the data treated by the principle of k-factor double-wavelength standard addition method.The recovery rate of both elements is found to be 95%~110% in the synthetic mixtures containing La and Pr with the concent ration ratio from 1∶1 to 1∶6.The satisfactory results were obtained.更多还原