An ionic liquid loaded magnetically confined polymeric mesoporous adsorbent for extraction of parabens from environmental and cosmetic samples

Abstract

An ionic liquid loaded magnetically confined polymeric mesoporous adsorbent based magnetic solid phase extraction (MSPE) procedure has been developed for the extraction and pre-concentration of parabens, namely methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP) and butyl paraben (BP) from environmental and cosmetic samples. In this study, hydrophilic ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride (BMIM-Cl) was loaded onto the surface of MNP grafted β-cyclodextrin polymer (MNP-βCD-TDI) to form a new ionic liquid based magnetic polymeric adsorbent (IL-MNP-βCD-TDI). This is a new approach for the extraction of parabens followed by high-performance liquid chromatography with diode-array detection (HPLC-DAD). The formation of IL-MNP-βCD-TDI was characterized by FT-IR, CHN, BET, SEM, TEM, VSM and XRD techniques and compared with native MNPs and MNP-βCD-TDI. Several variables were optimized thoroughly including the types of adsorbents used, concentration of ionic liquid loaded, amount of adsorbent, extraction and desorption time, types and volumes of desorption solvent, sample pH, ionic strength, and sample volume. Under-optimized conditions, excellent linearity was achieved in the range of 0.3–500.0 μg L⁻¹ for MP and EP, and 0.1–500.0 μg L⁻¹ for PP and BP, with a correlation coefficient of R² > 0.999. High sensitivity with limits of detection (LODs: 0.02 to 0.09 μg L⁻¹) and quantification (LOQs: 0.05 to 0.28 μg L⁻¹), and good recoveries (80.3–117.3%) were obtained with satisfactory relative standard deviations (RSDs: 1.1–14.9%). The developed material (IL-MNP-βCD-TDI) proved to be a simple and effective alternative adsorbent for the extraction of parabens from various types of environmental water samples and cosmetic products.