Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Indigowoad Leaves with Preconcentration by Cholesterol-Decorated Nickel Foam (NF) Dispersive Solid-Phase Extraction (DSPE) and Determination by Gas Chromatography-Mass Spectrometry (GC-MS)

Cholesterol-coated nickel foam (NF) was prepared by coating with tetraethyl orthosilicate, functionalization with 3-aminopropyltriethoxysilane, and modification with cholesterol. The subsequent characterization was carried out by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The cholesterol-coated NF was applied as the adsorbent for the dispersive solid-phase extraction of 16 polycyclic aromatic hydrocarbons (PAHs) in the indigowoad leaves traditional Chinese medicine. The primary experimental parameters affecting extraction were investigated with analysis by gas chromatography-mass spectrometry. The limits of detection were from 0.6 to 11.5 ng/mL and the relative standard deviations were from 0.84% to 9.8%. The recoveries were between 69.8% and 149.2%. The developed protocol was employed for the determination of PAHs in traditional Chinese medicines. The total mean concentrations of 16 PAHs, which are priority pollutants, were 1452.04 mu g/kg. The most abundant component in indigowoad leaves was acenaphthene (198.23 mu g/kg). The results demonstrated that the established method provided favorable performance and the cholesterol-coated NF adsorbent possessed high adsorption properties.