Assessment of toxic and essential heavy metals in imported dried fruits sold in the local markets of Jordan

In the present study, the concentrations of nine heavy metals (Fe, Zn, Mn, Cu, Mg, Cr, Ni, Cd, and Pb) in six different imported dried fruit samples of different brands (Mangoes, black raisins, figs, apricots, plums, and cranberries) were determined by Flame Atomic Absorption Spectroscopy (FAAS) after wet digestion. Samples were collected from different stores in Amman, Jordan. The average concentration of the selected metals in the analyzed samples were found to be in the range of 1.70-8.70 (Fe), 0.15-0.72 (Zn), 0.09-0.59 (Mn), 0.07-0.46 (Cu), 2.5-53.4 (Mg), 0.06-0.15 (Cr), 0.17-0.29 (Ni), 0.01-0.05 (Cd), and 0.11-0.57 (Pb) µg/g. The highest concentrations of Fe, Zn, Mn, Mg, and Ni were found in dried figs, highest concentrations of Cr, Cd, and Pb were found in dried apricots, and highest concentrations of Cu was found in dried black raisins. The results obtained in this study showed that Mg and Fe have the highest concentrations in all analyzed samples, whereas, the lowest concentrations obtained were for Cd and Cr. The concentrations of the highly toxic metals (Pb and Cd) in the all analyzed samples were found to be below or in good agreement with the permissible limits set by different health organizations. The figures of merit obtained for the FAAS calibration curves are brilliant with good linearity (r2 > 0.99). The FAAS method was validated by determining limit of detection (LOD), limit of quantitation (LOQ), and percent recovery (%R) for all investigated metals. The results obtained in this work were compared with the literature reported values

Perpendicular magnetization performance of hcp-cobalt nanocylinder array films electrodeposited from an aqueous solution containing cobalt (II)-citrate complexes

According to the potential–pH diagram for the Co2+–citrate–H2O system, Co2+–citrate complexes are stable at a pH ranging from 3 to 9. Titration curves and ultraviolet–visible absorption spectra confirm that the pH buffer associated with the formation of Co2+–citrate complexes is active at a solution pH ranging from 3 to 9. In this study, hcp-Co nanocylinder arrays were synthesized by electrodeposition into nanochannels of anodized aluminum oxide templates using an aqueous solution containing citric acid. Due to the formation of Co2+–citrate complexes, the growth rate of the Co nanocylinders significantly decreases in solution containing citric acid compared with that containing boric acid. The axial direction of Co nanocylinder arrays, which were electrodeposited using an aqueous solution containing citric acid, is consistent with the c-axis of the hcp-Co crystal. The synergistic contribution of the magnetic shape and magnetocrystalline anisotropies improves the uniaxial magnetization performance of the Co nanocylinder arrays. When the c-axis orientation of the hcp-Co crystal is increased, the coercivity and squareness of Co nanocylinder arrays increase up to 2.13 kOe and 0.84, respectively, at room temperature