Abstract
In efforts of trace analysis of heavy metals from a water sample, the sample preparation based on solid phase extraction (SPE) addressing the elimination of matrix interferences and the enrichment of metal ions is of vital importance in terms of selectivity and sensitivity. In this framework, the sorbents have been chosen depending on adsorbed target, adsorption capacity and ease in operation. The purpose of this work focused on magnesium ferrite (MgFe2O4) as an efficient sorbent toward divalent lead ions from water, which was applied to their preconcentration prior to quantifying by flame atomic absorption spectrometry (FAAS). Using a co-precipitation approach, the crystalline MgFe2O4 was obtained as evidenced by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The existence of nanospheres with a mean diameter of 50 nm was observed on scanning electron microscope (SEM) and their surface area was estimated to be 52.6 m2 g(1 by N2 adsorption-desorption isotherm. As a sorbent in a SPE technique, lead ions in a water sample were preconcentrated and then eluted from MgFe2O4 using 2.0 mol L(1 HCl, prior to being quantified by FAAS. MgFe2O4 showed the highest recovery of lead ions (100.7 %) in comparison with ferrite (Fe3O4, 48.1 %) and nickel ferrite (NiFe2O4, 81.7 %). The effects of lead ions preconcentration were examined involving time, dosage of sorbent, pH condition and eluting solution. Method validation was also carried out in compliance with the International Conference on Harmonisation (ICH Q2(R1)), including linearity, recovery, repeatability, limits of detection and quantification. The present report established a simple, fast, non-toxic and efficient procedure in the separation and enrichment of heavy metal ions from water with validated results.
