Combination of magnetic dispersive micro solid-phase extraction and supramolecular solvent-based microextraction followed by high-performance liquid chromatography for determination of trace amounts of cholesterol-lowering drugs in complicated matrices

A novel, efficient, rapid, simple, sensitive, selective, and environmentally friendly method termed magnetic dispersive micro solid-phase extraction combined with supramolecular solvent-based microextraction (Md mu-SPE-SSME) followed by high-performance liquid chromatography (HPLC) with UV detection is introduced for the simultaneous microextraction of cholesterol-lowering drugs in complicated matrices. In the first microextraction procedure, using layered double hydroxide (LDH)-coated Fe3O4 magnetic nanoparticles, an efficient sample cleanup is simply and rapidly provided without the need for time-consuming centrifugation and elution steps. In the first step, desorption of the target analytes is easily performed through dissolution of the LDH-coated magnetic nanoparticles containing the target analytes in an acidic solution. In the next step, an emulsification microextraction method based on a supramolecular solvent is used for excellent preconcentration, ultimately resulting in an appropriate determination of the target analytes in real samples. Under the optimal experimental conditions, the Md mu-SPE-SSME-HPLC-UV detection procedure provides good linearity in the ranges of 1.0-1500 ng mL(-1), 1.5-2000 ng mL(-1), and 2.0-2000 ng mL(-1) with coefficients of determination of 0.995 or less, low limits of detection (0.3, 0.5, and 0.5 ng mL(-1)), and good extraction repeatabilities (relative standard deviations below 7.8%, n = 5) in deionized water for rosuvastatin, atorvastatin, and gemfibrozil, respectively. Finally, the proposed method is successfully applied for the determination of the target analytes in complicated matrices.