Cold-induced Homogenous Liquid–Liquid Extraction Performed in a Refrigerated Centrifuge Combined with Deep Eutectic Solvent-based Dispersive Liquid–Liquid Microextraction for the Extraction of Some Endocrine Disrupting Compounds and Hydroxymethylfurfural from Honey Samples

Abstract

A cold-induced-homogeneous liquid–liquid extraction method combined with deep eutectic solvent-based dispersive liquid–liquid microextraction has been done to extract several endocrine disrupting compounds (phenol, p-chlorophenol, p-nitrophenol, octylphenol, methyl paraben, ethyl paraben, butyl paraben, and bisphenol A) and hydroxymethylfurfural from honey samples before their determination by gas chromatography–mass spectrometry. In this method, two ternary deep eutectic solvents including tetrabutyl ammonium chloride: dichloroacetic acid: ethylene glycol (hydrophilic) and tetrabutyl ammonium chloride: dichloroacetic acid: decanoic (hydrophobic) acid deep eutectic solvents are prepared and used as the extraction solvents in the developed method. The analytes are extracted by a two-step extraction procedure in which they are first extracted into the hydrophilic deep eutectic solvent and then transferred into a few microliters of the hydrophobic deep eutectic solvent for more concentration. In both steps, phase separation is done by centrifugation at low temperature. The method was optimized and validated and the results showed that the method had low limits of detection (0.21–0.50 ng g−1) and quantification (0.72–1.7 ng g−1), wide liner ranges, and an acceptable repeatability (relative standard deviation≤12). Lastly, the developed method was applied on different honey samples and bisphenol A, p-nitrophenol, and hydroxymethfurfural were found in some of them.