Synthesis and application of cerium oxide nanoparticles for preconcentration of trace levels of copper in water and foods followed by flame atomic absorption spectrometry

Abstract

In the present work, microwave method has been employed for synthesis of cerium oxide nanoparticles (CeO2 NPs) and it was used for preconcentration of trace levels of Cu(ІІ) in different real samples followed by flame atomic absorption spectrometry. The results of X-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM) show that CeO2 NPs were successfully synthesized in the size of 10–20 nm. By using a batch method, CeO2 NPs have been used as efficient, easy to synthesize and efficient adsorbent for highly rapid solid phase extraction of Cu(ІІ) in different real samples for the first time. The effects of different parameters affecting the extraction efficiency such as pH, extraction time, type and concentration of desorbent solvent and desorbent time were completely investigated and optimum conditions selected. Under the optimum conditions, the calibration curve was linear in the range of 10–300 ng cm−3 Cu(ІІ) with correlation coefficient of 0.998. The relative standard (RSD, %) based on six replicate analysis of 50 ng cm−3 Cu(ІІ) was 3.3%. In order to check the accuracy of the proposed method certified reference material, CRM-TMDW and GBW07605 tea reference material, with the known amounts of 20 ng cm−3 Cu(ІІ) and 17.3 ± 0.3 µg g−1 Cu, respectively, were analyzed and the obtained results (19.5 ± 1.0 ng cm−3 Cu(ІІ) for CRM-TMDW and 17.0 ± 0.7 µg g−1 Cu) show very good agreement with the CRM certified values (Student t-test, 95% confidence limit, n = 5). Finally the proposed method was successfully applied for determination of trace levels of Cu(ІІ) in different water (tap, spring and river) and food samples (black tea, lentil, sesame, cabbage, wheat and liver).