Analysis of alkylphenols, bisphenols and alkylphenol ethoxylates in microbial-fermented functional beverages and bottled water: Optimization of a dispersive liquid-liquid microextraction protocol based on natural hydrophobic deep eutectic solvents

In this work, the analysis of alkylphenols, bisphenols and alkylphenol ethoxylates in bottled waters, kombuchas and water kefir was performed through a vortex-assisted dispersive liquid-liquid microextraction method based on a natural hydrophobic eutectic solvent. For this purpose, mixtures of monoterpenes and fatty acids were employed. Different factors affecting extraction were optimized and the method was validated in terms of matrix effect, linearity, limits of detection and recovery. Recovery values varied between 70.0 and 124.3% (except for 4tert-butylphenol: 67.0% and 4-n-nonylphenol: 60.8% in water kefir) and limits of detection were in the range 0.10 ng/L - 2.99 mu g/L. Finally, 8 bottled waters, 8 kombuchas and 4 water kefirs were analyzed and 4-tertoctylphenol monoethoxylate was detected in water (20.28 +/- 0.99 - 62.08 +/- 3.63 mu g/L). This is the first application analyzing xenobiotic contaminants in kombucha and water kefir and the first time in which the three types of compounds are simultaneously extracted by dispersive liquid-liquid microextraction.

Automated summary

This study conducted the analysis of alkylphenols, bisphenols, and alkylphenol ethoxylates in bottled waters, kombuchas, and water kefir using a vortex-assisted dispersive liquid-liquid microextraction method with a natural hydrophobic eutectic solvent. The method was validated for matrix effect, linearity, limits of detection, and recovery, showing promising results for the extraction of these compounds in different beverages. The study also detected specific contaminants in the analyzed samples, providing valuable insights for future research in this area.