中文摘要：

偶氮胂Ⅲ分光光度法是测定元素钐的重要手段。但是，溶液中有共存离子Ca2＋、F-会对计量产生一定的干扰。通过改变溶液中Ca2＋、F-含量，研究它们在偶氮胂Ⅲ分光光度法测定钐中的影响规律。实验结果表明，当溶液中不含Sm3＋时，F-浓度的变化对吸光度没有影响；当溶液中含有Sm3＋时，随着F-浓度的增加，溶液吸光度减小。随着Ca2＋浓度的增加，溶液吸光度呈明显增大趋势，但当溶液中含有Sm3＋时，Ca2＋对吸光度增大幅度有减弱的趋势。最后，获得了溶液中同时存在CaCl2、CaF2时对偶氮胂Ⅲ分光光度法检测Sm元素吸光度影响的定量规律，其最大相对误差为2．70％。

英文摘要：

Spectrophotometric method with arsenazo Ⅲ is an important method for determination of samarium as a rare earth element. However, previous studies have shown that, existing of Ca2＋ and F- ions in the solution will have some interference to the measurement. In this paper, through changing the content of Ca2 ＋ and F - in the solution, the influence on the determination of samarium in spectrophotometry with arsenazo Ⅲ had been studied. The results show that, when Sm3＋ has not in the solution, changing of F- concentration has no effect on the absorbance as the signal of measurement, while the absorbance decreases with the increase of F - concentration in the solution of Sm3 ＋ contained. With the increase of Ca2 ＋ concentration in the solution, the absorbance is significantly increasing, but when the solution contains Sm3＋ , the increasing trend is weakened. Finally, the quantitative relationship with CaCl2 and CaF2 on the absorbanee is obtained, in which the maximum of relative error is 2.70 %.