Effervescent tablet-assisted switchable hydrophilicity solvent-based microextraction with solidification of floating organic droplets for HPLC determination of phenolic endocrine disrupting chemicals in bottled beverages

High-performance liquid chromatography (HPLC) determination of phenolic endocrine disrupting chemicals in bottled beverages was carried out using effervescent tablet-assisted switchable hydrophilicity solvent-based microextraction with solidification of floating organic droplets (ETA-SHS-ME-SFO). Octanoic acid was used as the extractant, which is a hydrophobic form of a switchable hydrophilicity solvent. The extractant was generated in-situ by the reaction between sodium octanoate and citric acid and collected after solidification in an ice-bath. Carbon dioxide gas was produced by the reaction between sodium bicarbonate and citric acid, which assisted the extraction of target compounds. Good linearity was obtained over the range of 0.03–3 µg mL −1 , with a correlation coefficient greater than 0.998. The relative recovery varied from 71.7% to 98.1%. The limit of detection ranged from 0.0002 to 0.0007 µg mL −1 . The intra- and inter-day relative standard deviations ( n  = 3) were less than 5.8%. Finally, the proposed method was successfully applied to the determination of the levels of bisphenol A, 4-nonylphenol, and 4-tert-octylphenol in bottled water, juice, and energy drink.