All-in-one approach enabling simultaneous derivatization and preconcentration of favipiravir for sensitive determination by GC–MS

In this research, a simultaneous derivatization and preconcentration method followed by gas chromatography–mass spectrometry (GC–MS) was established for the determination of favipiravir in synthetic serum, synthetic urine and domestic/synthetic wastewater samples. Acetic anhydride derivatization reaction was performed to obtain volatile and less polar derivatives of favipiravir. The derivatization reaction was simultaneously carried out with spraying based-liquid phase microextraction (SB-LPME) method. Eight different parameters such as acetic anhydride concentration, spraying cycle, pH/volume of buffer solution, extraction solvent type, initial sample volume, mixing type and mixing period were meticulously optimized by univariate optimization approach. Under the optimum SB-LPME-GC-MS method, limit of detection (LOD), limit of quantification (LOQ), dynamic range and coefficient of determination (R 2 ) were determined to be 16.8 µg/kg, 56.0 µg/kg, 0.063–5.32 mg/kg and 0.9998, respectively. Recovery experiments were carried out using spiked synthetic serum, synthetic urine and domestic/synthetic wastewater samples. The SB-LPME-GC-MS method exhibited satisfactory recovery results ranged from 75.6 to 134.9% for the samples. Based on these results, the developed analytical strategy has great potential to be used for the qualitative and quantitative determination of favipiravir in human serum, urine and wastewater samples.