Ultrasonication-facilitated synthesis of functionalized graphene oxide for ultrasound-assisted magnetic dispersive solid-phase extraction of amoxicillin, ampicillin, and penicillin G

A simplistic approach is presented for the synthesis of ultrasonically fabricated graphene oxide functionalized with polyaniline and N-[3-(Trimethoxysilyl)propyl]ethylenediamine. The synthesized nanocomposite was then employed for the facile, green, ultrasound-assisted, magnetic dispersive solid-phase extraction of amoxicillin, ampicillin, and penicillin G in milk samples and infant formula prior to high-performance liquid chromatography-ultraviolet determination. The designed nanocomposites were comprehensively characterized using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy. In order to achieve the best extraction efficiencies, the influential parameters including pH, amount of magnetic sorbent, type and volume of elution solvent, extraction time, sample volume, and desorption time were assessed. At the optimum conditions, linear ranges of 2.5–1000 (μg L⁻¹) for ampicillin and penicillin G and a linear range of 2.5–750 (μg L⁻¹) were obtained for amoxicillin at optimum conditions. Moreover, the limits of detection (S/N = 3) of 0.5, 0.8, and 0.9 (μg L⁻¹) were obtained for amoxicillin, ampicillin, and penicillin G, respectively. The precision (relative standard deviations (%)) values of 3.1, 2.6, and 2.5 at the concentration of 50 μg L⁻¹ for seven replicates were obtained for ampicillin, amoxicillin, and penicillin G, respectively. The efficiencies of ≤ 96% and relative standard deviations of less than 3.1% were also obtained thereby confirming the high potential of the synthesized nanocomposites for simultaneous preconcentration and separation of the β-lactam antibiotics in complex matrixes.