Molecularly Imprinted Adsorbent and Its Magnetic Version for Solid Phase Extraction of D-Panthenol: Comparison of Synthesis Approaches, Properties, and Applicability for Different Real Samples Extraction

Abstract

This study demonstrates the development of HPLC-DAD method for determination of D-panthenol incorporating the molecularly imprinted solid-phase extraction for sample preparation. Two types of adsorbents, molecularly imprinted polymers synthesized by bulk polymerization (MIPs) and precipitation polymerization on the surface of magnetic particles (Fe₃O₄@MIP), were compared in terms of adsorption properties and application potential. D-panthenol, a bioactive compound of pharmaceutical and cosmetic products, was used as the template for imprinting. The optimal polymerization mixture included 4-vinylpyridine as the functional monomer and methanol as the porogenic solvent. The adsorption kinetics of the pseudo-second-order indicated chemisorption of the template onto the active sites of the adsorbent. The Freundlich isotherm adsorption model, which fitted experimental data, suggested the presence of heterogeneous sorption sites on the adsorbents. MIPs and Fe₃O₄@MIPs were employed as adsorbents for the solid-phase extraction of D-panthenol from various cosmetic samples (such as body milk and other personal care products) achieving good selectivity for the targeted substance. Recoveries of MIP- and Fe₃O₄@MIP-based extractions were 82.3% (RSD < 2.9%) and 85.8% (RSD < 3.6%), respectively. The proposed HPLC-DAD method exhibited satisfactory linearity over the concentration range of 5.6–100 µg mL⁻¹ (R² = 0.9989) and a limit of detection of 1.7 µg mL⁻¹.