Background: Heavy metals can lead to the harmful effects to both animals and human beings by migrating through the food chain and accumulating in the body of organisms. Consequently, it was significant to develop the effective method for the removal and determination of the trace heavy metals in environmental and biological samples. This study aimed to present a sensitive and simple magnetic solid phase extraction procedure for the preconcentration of Lead and Cadmium ions in the environmental water samples.

Materials and Methods: The factors affecting the extraction of the target metal ions such as pH, the ionic strength, sample volume and amount of adsorbent were studied and optimized. Dithizone modified silica-coated magnetic Fe3O4 nanoparticles (H2Dz-SCMNPs) were prepared and used for MSPE of trace amounts of Cr (III), Cu (II). The prepared magnetic nanoparticles were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Thermogravimetric analysis )TGA) and Fourier transform infrared spectroscopy (FT-IR).

Results: Under optimum conditions, calibration curve was linear in the range of 70ppb-20ppm of Pb with R²=0.999 and Pb was recovered (more than 99%) from the sample. Extraction efficiency is slightly lower for cadmium.

Conclusion: The proposed method showed some advantages to the former methods such as easy preparation of adsorbents, selectivity, precision, short times of pretreatment and high extraction yields, especially for lead. The proposed method was applied to natural and environmental water samples, which showed good agreement with reference method results.