A novel method for the determination of individual lanthanides using an inexpensive conductometric technique

Abstract

A new conductometric titration method is established to determine quantitatively lanthanide ions (Lns) using ethylenediaminetetraacetic acid (EDTA) as a ligand and α-hydroxy isobutyric acid (α-HIBA) as a co-ligand. The detection limit of Ln(III) ions was found to be 1 × 10⁻⁵ M using a 5-ring conductivity sensor of cell constant 0.774 cm⁻¹. The proposed method is tested for selective determination of individual lanthanides in the presence of interfering ions like selected alkali, alkaline earth, and transition metal ions. The method does not suffer from interference from any of these species. A mechanism for selective detection by conductometry is given. Gd(III) determination is verified with the spectrophotometric method.