高等学校化学学报 ›› 1981, Vol. 2 ›› Issue (2): 155.

• 论文 • 上一篇    下一篇

钼-羟胺-(5-Br-PADAP)三元络合物及其应用于钼的分光光度法测定

陈玉绶, 黄泽兴, 吕金桐, 张鲁连   

  1. 福州大学化学化工系
  • 收稿日期:1980-05-13 出版日期:1981-04-24 发布日期:1981-04-24

ON THE FORMATION OF THE TERNARY COMPLEX OF Mo(Ⅵ)-NH2OH-5-Br-PADAP AND ITS APPLICATION IN SPECTROPHOTOMETRIC DETERMINATION OF MOLYBDENUM

Chen Yushou, Huang Zexing, Lu Jintong, Zhang Lulian   

  1. Department of Chemistry, Fuzhou University, Fuzhou
  • Received:1980-05-13 Online:1981-04-24 Published:1981-04-24

摘要: 在弱酸性介质中,在有羟胺存在并煮沸的情况下,钼能与羟胺和2-[(5-溴-2-吡啶)偶氮]-5-(二乙氨基)苯酚(简称5-Br-PADAP)作用形成蓝色的不溶于水的三元络合物,但在聚乙二醇辛基苯基醚(简称OP)存在下可不析出沉淀。此三元络合物的组成为Mo(Ⅳ):NH2OH:5-Br-PADAP=1:1:1,其最大吸收在600—605毫微米,摩尔吸光系数为4.8×104,在10毫升显色液中含0.1%5-Br-PADAP溶液0.6毫升,钼量在30微克以下遵守比耳定律。我们采用在显色后加入混合掩蔽剂并煮沸的办法来消除共存离子的干扰,方法具有很高的选择性,尤其可在大量钨存在下直接测定钼。

Abstract: When the solution containing Mo(Ⅵ) is boiled in the presence of NH2OH, Mo(Ⅵ) can react with 5-Br-PADAP, forming a water insoluble blue ternary complex Mo(Ⅵ)-NH2OH-5-Br-PADAP. However, in the presence of OPthe complex does not precipitate. The molar ratio of the three components in the complex is estimated to be Mo(Ⅵ):NH2OH:5-Br-PADAP =1:1:1. The wavelength of maximum absorbance for the complex is 605 nm. The molar absorptivity is 48000 at 605 nm. The calibration curve follows Beer's law in the range from o to 30μg of Mo (Ⅵ) in 10ml solution. As contrary to the usual practice masking agent is added after the colour development, and then the solution is boiled again to eliminate the effect of interfering ions. It is found that the method proposed in this work has very high selectivity.

TrendMD: