Synthesis and application of molecularly imprinted polymer for highly selective solid phase extraction trace amount of sotalol from human urine samples: Optimization by central composite design (CCD)

A novel method is described for trace determination of sotalol, a beta-blocker drug, using molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography with UV detection (HPLC/UV). The synthesis of the molecularly imprinted polymer was performed using acrylamide, ethylene glycol dimethacrylate, dimethylformamide, 2,2'-azobisisobutyronitrile and sotalol as a functional monomer, cross-linker monomer, solvent, initiator, and target drug, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used for characterizing the synthesized polymers. Also, a central composite design under response surface methodology and chemometrics applied to investigate and optimize the molecularly imprinted solid-phase extraction procedure parameters such as pH, loading and eluent solvent flow-rate, eluent solvent volume and sorbent mass, that probably influence the extraction process, to achieve the highest sotalol extraction efficiency. Batch rebinding capacity of sotalol was determined from the derived Langmuir isotherm and was found to be 20.08 mg/g. At above specified conditions, the proposed MISPE-HPLC/UV method used for the separation of trace amounts of sotalol in human urine samples with acceptable high recoveries (97-102%) and RSD% lower than 5%. The limit of detection and limit of quantification of the method were 0.01 and 0.04 mu g/mL, respectively.