Ultrasonic-assisted dispersive micro solid-phase extraction based on melamine-phytate supermolecular aggregate as a novel bio-inspired magnetic sorbent for preconcentration of anticancer drugs in biological samples prior to HPLC-UV analysis.

In this work, a new bio-inspired magnetic sorbent doped melamine-phytate supermolecular aggregate (Fe3O4/MPA) was applied in ultrasonic assisted dispersive micro solid-phase extraction (Fe3O4/MPA-UA-DMSPE) for the extraction of trace quantities of tyrosine kinase inhibitors (TKIs) (dasatinib, erlotinib, nilotinib). For this purpose, a mixture of phytic acid and melamine formed a supramolecular aggregate. In fact, adhesion between the carbon frameworks and nanoparticles was achieved by phytic acid as a crosslinker in order to prevent pores from collapsing. Then, Fe3O4 magnetic nanoparticles were doped into the aggregate pores and used as a magnetic sorbent. Ultrasonication was performed to enhance the dispersion of the sorbent with high extraction recovery. The magnetic property of the sorbent, helped with the quick separation of drugs from biological samples after their interaction with the sorbent surface. Methanol containing imidazole, as an effective eluent was used for desorption of the TKIs from the sorbent prior to their quantification by HPLC-UV detection. The chemical characteristics of the prepared Fe3O4/MPA were studied by FT-IR (Fourier Transform-Infrared Spectroscopy) and XRD (X-ray diffraction) analytical techniques. Also, BET (Brunauer-Emmett-Teller) and BJH (Barrett-Joyner-Halenda) were used for calculating the specific surface area and pore characteristics. Under assessed conditions, the limits of detection (LODs) and the limits of quantitation (LOQs) were obtained in the range of 0.12-0.2 and 0.3-0.6 μg L-1 respectively. The intra-day and inter-day precisions (RSDs, n = 6) were lower than 5 and 7% respectively. Finally, the method was successfully applied for the determination of three anticancer drugs (TKIs) in human plasma, serum and urine samples with good recoveries.