“…Cui et al [16,17] studied the extraction of iron(III) from HCl by extractants N,N,N′,N′tetrabutylmalonamide (TBMA) and N,N,N′,N′-tetrabutyl-3β-hydroxyglutaramide (TBDGA). The extraction results were compared with those of N,N,N′,N′tetrabutylsuccinamide (TBSA) to understand the relationship between the chemical structure of the extractants and the iron(III) extraction degree.…”