Determination of Synthetic Phenolic Antioxidants in Edible Oils: A Vortex-Assisted Hydrophilic DES-LLME/HPLC Approach with Focus on PG and TBHQ

Synthetic phenolic antioxidants PG (propyl gallate), TBHQ (tert-butyl hydroquinone), BHA (butyl hydroxyanisole) are commonly used additives in edible oils, but excessive residues may pose health risks. Conventional detection methods suffer from high organic solvent consumption, complex pretreatment procedures, and environmental concerns. To address these limitations, this study developed a rapid, green and efficient analytical method combining deep eutectic solvent (DES)-based liquid-liquid microextraction (LLME) with high-performance liquid chromatography (HPLC) for the rapid determination of phenolic antioxidants in edible oils. Using an optimized hydrophilic DES system composed of choline chloride and 1,3-butanediol, (molar ratio 1:2), along with simplified extraction conditions (780 μL DES, 11 s vortex at room temperature), efficient extraction and enrichment of the target analytes were achieved. The method demonstrated excellent performance specifically for PG and TBHQ, exhibiting a wide linear range (1-400 μg/mL, R² > 0.9970), low limits of detection (0.12-0.28 μg/mL), satisfactory spiked recoveries (90.2 %-113 %), and good intra-day and inter-day precision (RSD < 5.0%). Analysis of real samples demonstrated that the proposed method is highly sensitive, operationally simple, and environmentally friendly for the analysis of PG and TBHQ, offering a promising alternative for rapid monitoring and food safety regulation of these two antioxidants in edible oils. It should be noted that the current hydrophilic DES system did not achieve optimal extraction efficiency for BHA, highlighting the need for further optimization toward a comprehensive multi-analyte approach.