Polyaniline-Modified Magnetic Halloysite Nanotube-Based Magnetic Micro-Solid-Phase Extraction for the Analysis of Polycyclic Aromatic Hydrocarbons in Beer Samples by Gas Chromatography-Mass Spectrometry

Polyaniline-modified magnetic halloysite nanotube composites (MHNTs@PANI) were evaluated for the first time as an efficient adsorbent for the magnetic micro-solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from beer samples prior to gas chromatography-mass spectrometric detection. MHNTs@PANI were prepared from naturally available material halloysite by coating magnetic HNTs with polyaniline. After characterization, MHNTs@PANI were used to extract fluorene, phenanthrene, anthracene, pyrene, benz [a] anthracene, and chrysene via π-π and hydrophobic interaction between PANI and analytes. The effects of the amount of adsorbent, ionic strength, type of eluent, extraction time, and desorption time were investigated. Under optimum conditions, good linearity was obtained for the analytes in the concentration range of 0.05–100 μg L−1 with R2 between 0.9962 and 0.9991. The limits of detection were in the range of 1.64–14.20 ng L−1 and the spiked recoveries ranged from 78.8 to 114.6%. The proposed method proved to be efficient, rapid, sensitive, and reliable, which has been successfully applied to the determination of PAHs in eight brands of beer samples.