Supramolecular solvents combined with layered double hydroxide-coated magnetic nanoparticles for extraction of bisphenols and 4-tert-octylphenol from fruit juices

A magnesium–aluminum layered double hydroxides coated on magnetic nanoparticles (Fe 3 O 4 @MgAl-LDHs NPs) combined with the supramolecular solvents (SUPRASs) as the magnetic supramolecular fluids were successfully applied to the extraction and determination of four phenolic compounds (Bisphenol-A (BPA), bisphenol-AF (BPAF), tetrabromobisphenol-A (TBBPA) and 4-tert-octylphenol (4-TOP)). Magnetic supramolecular fluids (ferrofluids) composites were prepared through adding the mixture of n -octanol and tetrahydrofuran in distilled water as the supramolecular solvents into the solution containing magnetic Fe 3 O 4 @MgAl-LDHs NPs. Under the optimized conditions, the calibration curve was obtained in range of 5–1000   μg   L −1 . The limits of detection (S/N   =   3) for BPA, BPAF, TBBPA and 4-TOP, were obtained for 0.54, 0.48, 0.37 and 0.63   μg   L −1 , respectively. The intra-day and inter-day precision (RSDs %) for bisphenols (BPs) and 4-TOP at 100 and 300   μg   L −1 were in the range of 4.0–7.8. The enrichment factors were between 16 and 24.