Preparation of magnetic carbonized polyaniline nanotube and its adsorption behaviors of xanthene colorants in beverage and fish samples.

• Magnetic carbonized polyaniline nanotube was prepared for colorants extraction. • Fe 3 O 4 nanparticals contributed to the separation and adsorption. • Adsorption kinetics and isotherms studies proved the adsorption mechanisms. • The proposed method was used to detect xanthene colorants in beverage and fish samples. Magnetic carbonized polyaniline nanotube composite (Fe 3 O 4 @c-PANI) was synthesized via a self-assemble approach for the extraction and determination of three xanthene colorants including erythrosine B (EB), phloxine B (PB) and rhodamine B (RB). The scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction were adopted to confirm the successful synthesis of Fe 3 O 4 @c-PANI. When Fe 3 O 4 @c-PANI was applied for extracting three xanthene colorants, satisfactory extraction recoveries ranging from 89.48% to 94.15% were obtained with the relative standard deviation value of 1.09%–4.01%. Compared with Fe 3 O 4 , c-PANI and commercial adsorbents, Fe 3 O 4 @c-PANI achieved better retraction recovery for three colorants. Furthermore, adsorption kinetics and isotherms studies were analyzed to prove the adsorption mechanism of anionic and cationic colorants on Fe 3 O 4 @c-PANI. The graphite layers and pyrrole groups of the as-prepared composite can provide hydrophobic, π–π and hydrogen bonding interaction with xanthene colorants. Fe 3 O 4 nanoparticles played dual-functional roles contributing to the separation and adsorption. Coupled with high performance liquid chromatography, the established magnetic solid phase extraction method was used for the analysis of beverage and fish samples. [ABSTRACT FROM AUTHOR]