Determination of Trace Amounts of Cd(II), Cu(II), and Ni(II) in Food Samples Using a Novel Functionalized Magnetic Nanosorbent

Abstract

This work describes a novel sorbent based on functionalization of magnetic nanoparticles by 2-aminobenzothiazole and its application in the extraction and preconcentration of trace amount of Cd(II), Cu(II), and Ni(II) ions. This nanosorbent was characterized by Fourier transfer infrared spectroscopy, thermal analysis, X-ray powder diffraction, elemental analysis, and scanning electron microscopy. The effects of various factors such as pH value, sorption time, sorbent dosage, type, volume, and concentration of the eluent as well as the elution time were investigated. Following the sorption and the elution of target analytes, the Cd(II), Cu(II), and Ni(II) ions were determined by flame atomic absorption spectrometry. Under the optimal conditions, the limits of detection (LODs) were 0.03, 0.009, and 0.1 μg L−1 for Cd(II), Cu(II), and Ni(II), respectively. Linearity was within the range of 0.1–75 ng mL−1 for Cd(II), 0.03–50 ng mL−1 for Cu(II), and 0.5–100 ng mL−1 for Ni(II) in the initial solution with r 2 values greater than 0.9978. The relative standard deviations of the method were less than 8.4 %. The preconcentration factor of the method was 277. The sorption capacity of this new sorbent was 65, 78, and 49 mg g−1 for Cd(II), Cu(II), and Ni(II), respectively. The proposed method was validated using two certified reference materials (LGC 6010 hard drinking water and NIST SRM 1515 apple leaves) in order to exhibit its applicability. Ultimately, this method was applied to the rapid extraction of the trace quantities of Cd(II), Cu(II), and Ni(II) ions in different food samples, and satisfactory results were obtained.