Synergy of iron-natural phenolic microparticles and hydrophobic ionic liquid for enrichment of tetracycline residues in honey prior to HPLC-UV detection.

Iron-natural phenolic microparticles were developed as absorbents for dispersive micro solid phase extraction (D-μSPE) synergistic with hydrophobic ionic liquid (IL) for dispersive liquid-liquid microextraction (DLLME) to enrich tetracycline residues, including tetracycline, doxycycline, oxytetracycline and chlortetracycline. In situ iron microparticles synthesized from betel nut natural reagent were employed as an adsorbent for D-μSPE. The hydrophobic IL [Hmim][PF6] was synergistically utilized as an extraction solvent to extract and accumulate adsorbents bound with tetracyclines before quantitation by HPLC-UV. The synergistic combination of DLLME with D-μSPE provided excellent extraction recovery compared with individual extraction. The developed method was successfully applied to enrich and determine tetracycline residues in honey samples, with recoveries ranging from 80.0 to 121.5% and providing high enrichment factors ranging from 61 to 197. This alternative method is simple and rapid, with high extraction efficiency and a high enrichment factor and is also environmentally friendly for the analysis of tetracyclines.