The determination of mineral acidity excess in solutions containing Ga(III), Al(III), Bi(III)

摘要

A new procedure is proposed to carry out volumetric determinations of the strong acid content of a solution in the presence of inorganic cations such as Ga3+, Al3+, Bi3+ which, showing in aqueous solution an acidic behaviour, introduce non negligible interferences in these determinations. Before the acid-base titration, an equivalent amount of a ligand, such as dihydrogen ethylendiamino tetraacetate is added, in order to strongly complex the cation masking it toward the successive addition of a strong base. Interferences are thus removed, and the volumetric determination of the strong acid excess plus the hydrogen ions set free from the ligand, as a consequence of the complex forming reaction, can be accurately carried out, in the presence of a colorimetric indicator. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 14]