Dispersive Solid‐Phase Extraction of Polycyclic Aromatic Hydrocarbons in Black and Green Tea using a Chitosan/Polyaniline/Graphene Nanocomposite

Abstract

Abstract A dispersive solid‐phase extraction (d‐SPE) strategy was established employing a chitosan/polyaniline/graphene (CS/PANI/G) nanocomposite to isolate and quantify seven polycyclic aromatic hydrocarbons (PAHs) in black and green tea, coupled with HPLC‐FLD detection. The integration of graphene's porous framework with the functional amine and hydroxyl groups of chitosan and polyaniline generated strong π–π stacking and cation–π interactions, thereby enhancing adsorption and release efficiency. Comprehensive material characterization using SEM, HRTEM, FTIR, XRD, and BET confirmed a large surface area (318.2 m 2 g −1 ) and abundant active sites tailored for PAH binding. Analytical validation demonstrated excellent linearity (0.50–100 µg kg −1 , R 2 ≥ 0.998), low detection (0.073–0.480 µg kg −1 ) and quantification limits (0.881–1.455 µg kg −1 ), high recoveries (88.0–112.1%), and good precision (RSD < 4.1%). The nanocomposite maintained performance over five reuse cycles, underscoring its stability. Relative to conventional SPE sorbents, the CS/PANI/G material provided improved sensitivity, higher recoveries, and simpler operation. Overall, this study introduces CS/PANI/G as an innovative and sustainable nanosorbent for trace‐level determination of hazardous PAHs in complex food systems.