Ultrasound-assisted mixed hemimicelle magnetic solid phase extraction followed by high performance liquid chromatography for the quantification of atorvastatin in biological and aquatic samples

Abstract

A new method based on the combination of ultrasound-assisted magnetic solid phase extraction (USA-MSPE) and high performance liquid chromatography-UV-Vis (HPLC-UV-Vis) was developed for the isolation and preconcentration of atorvastatin (AT) from urine, plasma and water samples using sodium dodecyl sulfate coated Fe₃O₄ magnetic nanoparticles (MNPs) as a sorbent. The properties of Fe₃O₄ NPs including strong magnetism and high surface area were utilized effectively in the MSPE process. The prepared magnetic nanoparticles were characterized by transmission electron microscopy and X-ray diffraction. The effects of different parameters influencing the extraction efficiency including pH, the amount of Fe₃O₄ nanoparticles, the amount of SDS, extraction time, desorption solvent, desorption time and solvent volume were optimized. Additionally, the effect of sample volume on the extraction recovery of AT was studied. Under optimized conditions, the method was successfully applied to the extraction of atorvastatin from water samples and an absolute recovery of 99.8%, a detection limit of 0.1 ng L⁻¹ and a relative standard deviation of <6.8% were obtained. The method linear dynamic range is in the range of 0.4–500 μg L⁻¹ with R² = 0.9999. The relative recoveries in different aquatic and biological matrices were investigated and values of 88.9 to 109.5% were obtained.