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 Zn 2+ in different real samples followed by flame atomic absorption spectrometry. Cerium oxide nanoparticles (CeO 2 NPs) are synthesized by microwave method and modified by polythiophene (PT) to synthesize CeO 2 -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 Zn 2+ 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 CeO 2 -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 µg L −1 Zn 2+ with a regression coefficient of 0.9988. The limit of detection was 0.42 µg L −1 Zn 2+ based on six replicate analyses of blank sample. The relative standard deviation based on five replicate analyses of a solution containing 75 µg L −1 Zn 2+ 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.