Polymer Bulletin, Vol.77, No.1, 323-337, 2020
Polythiophene-coated cerium oxide nanocomposite for efficient solid-phase extraction of trace levels of Zn2+ followed by flame atomic absorption spectrometry
An efficient solid-phase extraction method based on polythiophene-coated cerium oxide nanocomposite was used for preconcentration of trace levels of Zn2+ in different real samples followed by flame atomic absorption spectrometry. Cerium oxide nanoparticles (CeO2 NPs) are synthesized by microwave method and modified by polythiophene (PT) to synthesize CeO2-PT nanocomposite. The synthesized nanocomposite was characterized by the Fourier-transform infrared spectrophotometry and scanning electron microscopy. The main parameters affecting the recovery percentage of Zn2+ including pH, amounts of adsorbent, extraction time and desorption time were investigated and optimized by Box-Behnken experimental design. The optimum conditions are pH 8.1, 10 mg CeO2-PT nanocomposite, 10 min extraction time and 4 min desorption time. Under the optimum conditions, the calibration curve was determined in the range of 2-150 mu g L-1 Zn2+ with a regression coefficient of 0.9988. The limit of detection was 0.42 mu g L-1 Zn2+ based on six replicate analyses of blank sample. The relative standard deviation based on five replicate analyses of a solution containing 75 mu g L-1 Zn2+ was 2.9%. Finally, the applicability of the proposed method was checked by the analysis of different real samples including different water, food and fruit samples.
Keywords:Solid-phase extraction;Polythiophene-coated cerium oxide nanocomposite;Flame atomic absorption spectrometry;Zinc;Box-Behnken optimization