Hydrophobic deep eutectic solvent-based vortex assisted liquid–liquid microextraction for the determination of famciclovir in water samples coupled with high performance liquid chromatography

Deep eutectic solvents (DESs), as a new generation of green solvents, have the advantages of simple preparation procedure, low toxicity, non-volatility and good extraction performance in replacing traditional volatile organic solvents. In this work, a series of hydrophobic DESs were prepared and used as extraction solvent for the vortex-assisted liquid–liquid micro-extraction and determination of famciclovir in environmental water samples coupled with high performance liquid chromatography. The key factors affecting the extraction efficiency were investigated by using single-factor test and response surface methodology. The optimized conditions were as follows: the DES type (thymol: ethyl aniline formate, molar ratio 3:1), DES dosage 50 mg, extraction time 1.5 min, solution pH 6.0, diluent volume 100 µL. Under the optimal conditions, calibration curve of the proposed method was in the range of 0.7–2000 μg/L with correlation coefficient (r2) higher than 0.9997. The limit of detection (LOD, S/N = 3) and the limit of quantitation (LOQ, S/N = 10) were 0.2 and 0.7 μg/L, and the intra-day and inter-day precision were less than 2.3 % and 1.6 %, respectively. Finally, this method was successfully used for the determination of trace famciclovir in environmental water samples with recoveries in the range of 86 %-118 %.