偶氮胂III作为金属变色指示剂用于在微碱性介质中络合滴定法测定钙。

Arsenazo III as metallochromic indicator for complexometric determination of calcium in slightly alkaline medium.

作者信息

Michaylova V, Kouleva N

机构信息

Department of Chemistry, University of Sofia, Sofia 26, Bulgaria.

出版信息

Talanta. 1973 May;20(5):453-8. doi: 10.1016/0039-9140(73)80182-1.

DOI:10.1016/0039-9140(73)80182-1

PMID:18961304

Abstract

Arsenazo III is proposed as metallochromic indicator for calcium in slightly alkaline medium. The visual titration with EDTA was performed at pH 8 and 40 microg-12 mg of calcium were determined. The interference of some ions was considered and it was found that phosphate does not interfere appreciably. Spectrophotometric detection of the end-point was used for titration of calcium in the presence of magnesium at pH 9. For the estimation of the titration error, the conditional stability constants of the calcium-arsenazo III complex were found.

摘要

偶氮胂III被提议作为在弱碱性介质中测定钙的金属显色指示剂。用EDTA进行目视滴定是在pH 8时进行的，测定的钙含量为40微克至12毫克。考虑了一些离子的干扰，发现磷酸盐的干扰不明显。在pH 9时，在镁存在的情况下，采用分光光度法检测终点来滴定钙。为了估计滴定误差，测定了钙-偶氮胂III配合物的条件稳定常数。