Extraction-preconcentration Mercury ion by Ghezeljeh montmorillonite nanoclay as a new native adsorbent from food and water samples

Ghezeljeh montmorillonite nanoclay or “Geleh-Sar-Shoor” (means head-washing clay) used as a native adsorbent to extraction-preconcentration mercury ions from a variety of real water and fish samples have been investigated in a batch system followed by atomic absorption spectroscopy (AAS) with vapor generation accessory (VGA) system. The clay was characterized by using FT-IR, SEM-EDS, XRF, XRD, CEC, Specific surface area and Zeta potential. The results of XRD, FT-IR, Zeta potential and CEC of the Ghezeljeh clay confirm that montmorillonite is the dominant mineral phase. On the basis of on SEM images, the distance between the layers is in nm level. The outcome of varying parameters and interfering ions were studied. Detection and quantification limits, preconcentration factor, and adsorption capacity were calculated. The Langmuir and Freundlich equations showed the finest fit to the equilibrium data. The adsorption procedure follows a pseudo-second-order reaction pattern. Calculation of ΔG0, ΔH0 and ΔS0 displayed that the nature of Hg(II) ions adsorption is endothermic and favorable at upper temperature.