Selective preconcentration, separation and speciation of ferric iron in different samples using N,N′-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane

The synthesis and analytical applications of N,N ' -bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane (HBDAP) are described. This compound reacts with Fe(III) in the range of pH 3-6 to produce a red complex (2:3 mol ratio of Fe(III)/HBDAP) soluble in chloroform. The investigation included a study of the characteristics that are essential for solvent extraction and for spectrophotometric determination and speciation of iron. A highly sensitive, selective and rapid spectrophotometric method is described for the determination of trace amounts of iron(III) by HBDAP. The complex obeys Beer's law from 0.056 to 1.68 mg l(-1) with an optimum range. The detection limit (taken as three times the standard deviation of the reagent blank) is similar to 1.23 x 10(-7) M Fe(III) and the limit of quantitation (taken as ten times the standard deviation of the reagent blank) is about 4.11 x 10(-7) M Fe(III). A single extraction gave a good separation of iron(III) from iron(II). Good separation of Fe(III) from Ni(II), Fe(II), Co(II), Cd(II), Mn(II), Zn(II), Pb(II) was also achieved at pH 3-5. (C) 2001 Elsevier Science B.V. All rights reserved.