论文部分内容阅读
LaNi_5合金是一种储、放氢性能好的金属间化合物。目前对该类合金分析方法的报道极少。仅在LaNis和SmCo_5合金分量分析法的研究之后,本文提出了交流示波极谱法测定LaNi_5(也适用SmCo_5)合金分量的新方法。镧、镍离子均能与EDTA生成络合物,稳定常数为15.50、18.60(钐为17.14,钴为16.30)。可见这些络合物是比较稳定的,但不能用EDTA直接分步滴定。如果在pH=5.6的试液中加入过量EDTA,使其与镧、镍络合,根据在此pH值时铅在示波极谱图上有敏锐切口的性质,用铅离子标准溶液滴定过量的EDTA,可得出镧、镍的总量,然后加入NaF,而
LaNi_5 alloy is a kind of intermetallic compound with good performance of hydrogen storage and desorption. At present, there are few reports on this type of alloy analysis method. Only after the study of LaNis and SmCo_5 alloy component analysis, this paper presents a new method for the determination of LaNi_5 (also applicable to SmCo_5) alloy by oscillopolarography. Both lanthanum and nickel ions can form complexes with EDTA with the stability constants of 15.50 and 18.60 (17.14 for samarium and 16.30 for cobalt). It can be seen that these complexes are relatively stable, but can not be directly titrated with EDTA. If the pH = 5.6 test solution by adding excess EDTA, and lanthanum, nickel complexation, according to the pH at this oscilloscope polarographic osculation polarogram has a sharp incision nature, with lead standard solution titration excess EDTA, you can get the total amount of lanthanum, nickel, and then add NaF