Simultaneous extraction of polycyclic aromatic hydrocarbons and tetracycline antibiotics from honey samples using dispersive solid phase extraction combined with dispersive liquid-liquid microextraction before their determination with HPLC-DAD

Abstract

Herein, a dispersive solid-phase extraction method combined with dispersive liquid-liquid microextraction was offered for the extraction of four polycyclic aromatic hydrocarbons (anthracene, fluorene, phenanthrene, and pyrene) and tetracycline antibiotics (tetracycline, oxytetracycline, and chlortetracycline) from honey samples, simultaneously. In this work, cobalt-gallic acid bio-metal organic framework was synthesized and 20mg of it was added into of 10mL the diluted honey solution to efficiently adsorb the analytes. After vortexing (3min) and centrifuging, the sorbent particles were eluted with 0.75mL acetonitrile under vortexing for 3min. In the following, this phase was mixed with 55µL [Ch: 4-chlorophenol]+[FeCl4]- magnetic deep eutectic solvent and rapidly injected into deionized water. After separating the extractant phase in the presence of an external magnet and diluting it with the mobile phase, it was injected into a high-performance liquid chromatography-diode array detector. Under optimum extraction conditions, extraction recoveries were in the range of 63–84%. The limits of detection of the opted polycyclic aromatic hydrocarbons and tetracyclines were in the ranges of 0.18–0.26 and 0.25–0.29ngg-1, respectively. Also, good repeatability (relative standard deviations ≤ 7.5 and 8.3% for intra– (n=6) and inter-day (n=4) precisions, respectively) was obtained. In summary, the validated method was successfully recommended for the determination of polycyclic aromatic hydrocarbons and tetracyclines in various honey samples and pyrene was found in two samples at 5.5 and 12.9ngg-1. The used bio-metal organic framework has sufficient ability in extraction of different classes of compounds (polycyclic aromatic hydrocarbons and antibiotics) from honey. Performing the microextraction step has direct effect in analysis of the analytes in low concentrations and the use of magnetic solvents, eliminate the use of centrifugation in this step.