Eco-friendly flow injection amperometric determination of tert-butylhydroquinone in edible oil samples using micelle-mediated reverse-phase dispersive liquid-liquid microextraction and unmodified screen-printed carbon electrode

Abstract

Lipid oxidation compromises the stability of edible oils, especially refined ones, due to reduced natural antioxidants. Synthetic antioxidants like tert-butylhydroquinone (TBHQ) are widely used but require careful monitoring. This study developed a rapid, low-cost, and environmentally friendly method using micelle-mediated reverse-phase dispersive liquid-liquid microextraction (RP-DLLMEM) combined with flow injection analysis (FIA) and electrochemical detection for TBHQ determination in oils. Oil samples (1.0 mL) were mixed with 2 mL Triton X-100 (30 mM) containing TBHQ, vortexed for 60 s, and centrifuged. Detection of TBHQ was carried out by using an FIA system and an unmodified screen-printed carbon electrode at 0.7 V. The method achieved recoveries of 95–109% in soybean, corn, and sunflower oils, with linearity from 15.2–1200 µmol L-1 (R² = 0.997), LOD of 5.0 µmol L-1, LOQ of 15.2 µmol L-1. RP-DLLMEM/FIA offers a simple, efficient, and green alternative to TBHQ analysis in edible oils.