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Abstract
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In this work, a magnetic nickel oxide/chitosan nanocomposite was fabricated by a facile precipitation approach.
The structure and morphological properties of the prepared nano-material were characterized via X-ray diffraction, Fourier transform infrared spectrometry, scanning electron microscopy and energy dispersive X-ray
spectroscopy. The prepared nanocomposite was used as a nano-sorbent for the magnetic solid-phase extraction
(MSPE) of the trace amounts of zinc (Zn(II)) ions from aqueous solutions followed by flame atomic absorption
spectrometric (FAAS) detection. Several factors influencing the extraction efficiency of Zn(II) ions such as pH,
extraction time, amount of the nano-sorbent, elution conditions and sample volume were investigated and optimized. Under optimized conditions, the calibration curve with a liner dynamic range of 0.35 –15 ng mL− 1 was
attained. The preconcentration factor and limit of detection were 100 and 0.12 ng mL− 1, respectively. The
method precision was evaluated with seven replicates at the concentration level of 5 ng mL− 1 and the relative
standard deviations of 2.8% and 3.1% were obtained for intra-day and inter-day repeatability, respectively. The
applicability of the developed MSPE-FAAS method for the measurement of Zn(II) ions was validated by analyzing the certified reference material NIST SRM 1549. Zinc(II) ion concentration was measured in various real
samples including tap water, river water, well water, milk and powder milk using the method, and satisfactory
relative recovery values were acquired for the spiked samples.
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