Mahboube Shirani

In this study, zinc chromite spinel oxide (ZnCr 2 O 4 ) modified activated nanodiamonds (ZnCr 2 O 4@NDs), as a new generation of carbon -based nanocomposites , were synthesized and characterized. To assess the accuracy of the structure, some techniques such as Fourier -Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscopy, Energy Dispersive X -ray Spectroscopy, X -Ray diffraction, and Tunneling Electron Microscopy were utilized. Application of ZnCr 2 O 4 nanodiamonds with dispersive µ -solid phase extraction (DµSPE) before flow injection analysis coupled microwave plasma atomic emission spectrometry (FIA -MP -AES) presented significant results for preconcentration/separation and determination of trace and ultra -trace levels of nickel, cadmium, and cobalt ions. The linear ranges of 0.05 -1000 ( µg Kg - 1 ) for ta p water, green tea , and chamomile, and 0.05 -750 ( µg Kg - 1 ) for Hallilroud river and thyme, 0.05 -500 ( µg Kg - 1 ) for black tea, apple juice, and peach juice for Co2+, Cd2+, and Ni2+ . The LOD values of 0.0150 -0.0155 ( µg Kg - 1 ) were obtained for nickel, cobalt, and cadmium. The intra -day precision (repeatability) and the inter -day precision (reproducibility) (%) were ≤2.5 and ≤2.9, respectively. The applicability of the method was explored in water , herbal teas, and fruit juice samples , which represented recoveries (%) of 88.0 -100.0. Furthermore, application of BAGI, AGREE, AGREEprep, and CaFRI metric tools ratified the greenness of the method.