Acta Chimica Sinica ›› 1980, Vol. 38 ›› Issue (4): 323-330. Previous Articles     Next Articles

隐蔽剂在螯合滴定中的应用 Ⅵ.以苹果酸隐蔽轻稀土元素及其微量分光光度滴定

陈永兆, 李焕然   

  1. 中山大学化学系 广州
  • 收稿日期:1978-06-23 出版日期:1980-07-15 发布日期:2013-06-03

THE USE OF MASKING AGENTS IN CHELOMETRY Ⅵ. THE MASKING OF LIGHT RARE EARTHS WITH MALIC ACID AND THEIR MICROSPECTROPHOTOMETRIC TITRATION

CHEN YONG-ZHAO, LI HUAN-RAN   

  1. Chemistry Department, Sun Yat-Sen University, Guangzhou
  • Received:1978-06-23 Online:1980-07-15 Published:2013-06-03

Through preliminary experiments, we found that at pH 5.6 malic aoid hag a much more powerful masking action towards the light rare earths than lactic acid and glycerin acid.It was found that only malic acid can displace EDTA from the RE-EDTA complexes quantitatively.In this way, 40-1000μg of Ce(Ⅲ) or 50-500μg of the mixed light rare earths can be so titrated spectrophotometrically with 0.002 M lead nitrate solution using xylenol orange as indicator, while over 20 kinds of canons do not interfere.This method is highly selective and seems possible to be used in the titration of rare earths in minerals or in iron and steel samples with preliminary separations.