Rapid Determination of Vitamin D(3) in Aquatic Products by Polypyrrole-Coated Magnetic Nanoparticles Extraction Coupled with High-Performance Liquid Chromatography Detection

A method using polypyrrole-coated Fe(3)O(4) (Fe(3)O(4)@PPy composites) based extraction coupled with high performance liquid chromatography was developed for adsorption and detection of trace vitamin D(3) (VD(3)) in aquatic products. The fabricated Fe(3)O(4)@PPy composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Fe(3)O(4)@PPy composites showed efficient adsorption of VD(3) at pH 9.0 and 25 °C with a dose of 25 mg per 10 mL of sample solution and an adsorption time of 11 min. Methanol was selected as the desorption solvent to recover VD(3) from Fe(3)O(4)@PPy composites after 3 min of static treatment. Fe(3)O(4)@PPy composites can be used for VD(3) adsorption at least two times. The developed method showed a good linearity for VD(3) determination in the range of 0.1–10 μg/mL with a correlation coefficient of 0.9989. The limits of detection and quantification were 10 ng/mL and 33 ng/mL, respectively. The recovery of VD(3) in a spiking test was 97.72% with a relative standard deviation value of 1.78%. The content of VD(3) in nine aquatic products was determined with this method. Our results show that Fe(3)O(4)@PPy composites provide a convenient method for the adsorption and determination of VD(3) from the complex matrix of aquatic products.