Rapid Determination of Phenolics in Food Packaging by Magnetic Solid-Phase Extraction and High-Performance Liquid Chromatography

A method for magnetic solid-phase extraction was developed for the preconcentration of bisphenol A, bisphenol AF, tetrabromobisphenol A, and 4-tert-octylphenol from food containers and packaging materials. Cetyltrimethylammonium bromide was added to a solution of magnetic nanoparticles to enhance adsorption of the analytes prior to high-performance liquid chromatography. The effects of the amount of surfactant, the amount of magnetic nanoparticles, the pH, the adsorption time, the desorption solution, and the reuse of the extractant were optimized. The linear dynamic ranges were from 0.05 to 25 milligrams per liter. The limits of detection were between 1.21 and 2.48 micrograms per liter, the limits of quantification were from 4.03 to 8.27 micrograms per liter, and the relative standard deviations were between 2.2 and 4.1 percent. This magnetic solid-phase extraction approach was successfully employed for the analysis of plastics with recoveries from 88.0 to 101.1 percent and relative standard deviations between 2.3 and 5.4 percent.