Effect of Magnetized Solvent on Sorbent Porosity for Remdesivir Extraction

Researchers from the Ferdowsi University of Mashhad in Mashhad, Iran tested a new type of sorbent for effectively extracting remdesivir from samples. Their findings were published in the Journal of Chromatography A (1).

Medication prepared for people affected by Covid-19, Remdesivir is a selective antiviral prophylactic against virus that is already in experimental use, conceptual image | Image Credit: © digicomphoto - stock.adobe.com

Scientists are hard at work researching new methods to treat viruses like COVID-19 and other new and emerging diseases. As a byproduct of these research efforts, large amounts of biotoxic waste from compounds, raw materials, intermediates, and metabolites, are discharged into the environment. Of these drugs, remdesivir, which is a nucleoside analog used to treat ribonucleic acid (RNA) virus infections, including COVID-19, has demonstrated potent in vitro and in vivo antiviral activity (2).

Detecting and effectively removing pharmaceutical products is crucial for monitoring and controlling environmental impact. To effectively measure analytes at low concentrations in real samples, it is important to create a suitable sample preparation method that preconcentrates analytes and reduces the matrix effect prior to instrumental analysis. According to the scientists, adsorption-based sample preparation methods, such as solid-phase extraction (SPE), have proven very practical and powerful for selectively enriching target compounds and minimizing matrix effects for routine analysis. Nanomaterials possess unique properties, but their application in SPE is rather limited due to several drawbacks, such as aggregation, strongly decrease column sorption capacity. Magnetic SPE (MSPE) is a fast and simple substitute technique created with based magnetic nanoparticles, which are coated with advanced materials. This makes it easier for magnetic particles preclude the steps of filtration or centrifugation.

In this study, magnetic graphene oxide@UiO-66 (MGO@UiO-66) nanocomposite was investigated as a sorbent, with emphasis on its synthesis and properties. The prepared sorbent was used for the MSPE of remdesivir from water and plasma samples. The extracted remdesivir was quantitatively determined using high-performance liquid chromatography with a photodiode array detector (HPLC-PDA). Various techniques were used to characterize the MGO@UiO-66 sorbents, including Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating-sample magnetometry. Additionally, the optimization of extraction parameters, such as desorption solvent and its volume, sorbent amount, pH, desorption conditions, and extraction time were investigated and studied. For this study, magnetized dimethylformamide (DMF) was used as a nonwatery magnetized solvent, with the DMF flowing through a strong magnetic field before being used for sorbent synthesis.

After the field is removed, there could be residual structuring or altered hydrogen bonding in the DMF that persists for short periods of time, potentially influencing their behavior as a solvent during synthesis. These effects can affect how MOF and GO interact with the DMF, which could lead to more effective nucleation or different particle growth dynamics. Though DMF is not magnetic itself, this temporary alteration in molecular interactions could influence particle growth and material porosity. Additionally, the effects of magnetized solvent on synthesized sorbents were comprehensively analyzed.

Under optimized conditions, the calibration plot for remdesivir was linear within the range of 0.1–300 ng mL^-1 and limits of detection (0.03 ng mL^-1). The MSPE-HPLC-PDA method showed good extraction recovery and relative standard deviations (RSD) in the ranges of 95.5–99.5% and 3.8–4.7%, respectively. Additionally, the method effectively utilized to analyze remdesivir in water and plasma samples, resulted in relative recoveries ranging from 95.5–99.3%.

References

(1) Asefi, M.; Amiri, A.; Gholizadeh, M. Effect of Magnetized Solvent on the Porosity of Magnetic Graphene Oxide@Zirconium-Based Metal-Organic Framework Sorbent for Efficient Extraction of Remdesivir. J. Chromatogr. A 2025, 1748, 465839. DOI: 10.1016/j.chroma.2025.465839

(2) Remdesivir. Drugbank 2025. https://go.drugbank.com/drugs/DB14761 (accessed 2025-4-10)