Extraction of Covid-19 drug (Favipiravir) from plasma samples by yolk-shell mesoporous silica before HPLC-MS/MS determination

In this work, a simple and inexpensive dispersive solid phase extraction method using SiO @MCM-41-Co O yolk shell as a sorbent was developed for the extraction of favipiravir from plasma samples. The sorbent was synthesized with a simple and novel method. Optimization of the extraction procedure was performed using one parameter at a time strategy. For selective measurement of favipiravir in real samples, multiple reaction monitoring mode in high-performance liquid chromatography-tandem mass spectrometry was used. The synthesized sorbent presented a high adsorption capacity for favipiravir due to its mesoporous structure and different interactions. After optimization of effective parameters including the amount of sorbent, pH, and adsorption and desorption times, the analytical parameters of the method were evaluated. The developed method exhibited a wide linear range from 0.50 to 1000 μg/L. The detection limit and quantification limit of the method were 0.15 and 0.50 μg/L, respectively. The relative standard deviation of the method was obtained by using intra- and inter-day tests, and in both cases, it was less than 6.0%. Finally, the method was successfully used to measure favipiravir in plasma samples with relative recoveries in the range of 87-105%.