Synthesis, spectral studies and complexation properties of N,N′-bis(5-bromo-salicylidene)-2-hydroxy-1,3-propanediamine (BSHP) and iron extraction with BSHP from oils

Abstract

A Schiff base was synthesized by reaction of 1,3-diamino-2-propanol and 5-bromo-2-hydroxy benzaldehyde. The Schiff base N,N′-bis(5-bromo-salicylidene)-2-hydroxy-1,3-propanediamine (BSHP) was characterized by elemental analysis, 1H NMR, 13C NMR, IR, UV-Vis spectral studies. The complexation of iron with BSHP was investigated spectrophotometrically. The extraction of iron from oil phase to aqueous phase was carried out with BSHP. Extraction conditions were optimized using central composite design. Optimum extraction conditions were found to be 32°C, 2 mL/g for the ratio of the volume of the Schiff base solution to the amount of oil, and 11 min for the stirring time. The method has been validated by using oil based metal standard, obtaining satisfactory results. The limit of detection (LOD) of the improved method is 0.04 μg/g. It has been applied to analysis of different oil samples. The concentrations of iron in olive, sunflower and corn oils were found to be 0.65 ± 0.02, 0.41 ± 0.01, 0.36 ± 0.03 μg/g, respectively. A simple, cheap, rapid, efficient, sensitive and accurate alternative analytical method for the iron determination in oils has been presented in this paper.