Molecularly Imprinted Polymer‒Solid‐Phase Extraction Coupled With High‐Performance Liquid Chromatography‐Ultraviolet Detection for Selective Determination of Ketoconazole in Cosmetic Shampoo

A molecularly imprinted polymer (MIP) was successfully synthesized through precipitation polymerization for the purpose of selectively extracting ketoconazole (KCZ) from cosmetic shampoo matrices. The polymerization process employed methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, azobisisobutyronitrile as the initiator, and KCZ as the template within an acetonitrile/acetic acid (9:1, v/v) solvent system. Conditions for synthesis were optimized to enhance efficiency. Material characterization, conducted via Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller analysis, confirmed the successful formation of the polymer. The MIP demonstrated a maximum adsorption capacity of 1.90 mg/g and a recovery rate of 94.98%, which were significantly higher compared to those of the non-imprinted polymer (0.47 mg/g and 39.67%, respectively). The material exhibited high selectivity for KCZ over structurally similar compounds. A high-performance liquid chromatography method with ultraviolet detection was developed and validated utilizing the synthesized MIP as a selective sorbent. The method displayed excellent linearity over a concentration range of 0.05-500 µg/mL, with a limit of detection of 0.193 µg/g, and a limit of quantification of 0.643 µg/g. These parameters indicate approximately a tenfold enhancement in sensitivity relative to previously reported ultrasound-assisted extraction methods. The method demonstrated excellent precision (relative standard deviation ≤ 6.06%) and high recovery rates (80.41%-98.86%) in real samples. Consequently, this study establishes a cost-effective, selective, and highly efficient approach for the determination of trace levels of KCZ in cosmetic products.