Electrochemical Synthesis of Polyaniline@Nano Zinc Oxide/Modified Multiwalled Carbon Nanotubes Nanocomposite Coating for Solid Phase Microextraction of Some Polycyclic Aromatic Hydrocarbons in Coffee and Grilled Meat

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds resulting from incomplete burning of organic materials. This work describes the successful layer-by-layer fabrication of a novel zinc oxide nanocomposite made of zinc oxide nanoparticles, aniline, sodium dodecyl sulfate, and modified multi-walled carbon nanotubes on a stainless steel wire by electrodeposition. The coating and extraction conditions were screened, optimized, and validated using factorial design and central composite design, respectively. The prepared nanocomposites were characterized by the Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction analysis, and Brunauer-Emmett-Teller techniques. It featured a porous structure, excellent heat stability, and a high extraction capacity. It also adhered well to the steel surface. Extracting PAHs was optimized through experimental design. The optimal conditions obtained for extraction were 60 min, 30%, and 30°C for extraction time, amount of salt, and extraction temperature, respectively. The validated method generally showed a linear range between 0.01 to 1.50 µg/mL with a linearity of (R²) of 0.9902–0.9992, limits of detection less than 0.003 µg/mL, limit of quantification lower than 0.010 µg/mL, and relative standard deviation percent less than 45. Recovery values of the analytes in food samples varied between 53.4% and 110.1%. The proposed method was employed in the extraction and determination of some PAHs in some food samples while naphthalene, anthracene, phenanthrene, benzo[a]pyrene, and benz[a]anthracene were detected in certain food samples. Overall, our research suggests a novel nanocomposite as a potential fiber coating that enables high-capacity PAH extraction.