Schiff base network-1 incorporated monolithic column for in-tube solid phase microextraction of antiepileptic drugs in human plasma

A novel monolithic column incorporated with Schiff base network-1 (SNW-1) was prepared for in-tube solid phase microextraction (SPME) of antiepileptic drugs. The SNW-1 nanoparticles was synthesized by a solvent thermal method and embedded in the poly(glycidyl methacrylate-ethylene glycol dimethacrylate) (GMA-EGDMA) monolithic column by in situ polymerization. The amount of SNW-1 in polymerization solution for preparation of monolithic column was optimized. Fourier transform infrared spectrometry and scanning electron microscope were used to characterize the obtained monolithic column. The SNW-1-monolithic column was connected to the high-performance liquid chromatography (HPLC) system and applied for online extraction and analysis of antiepileptic drugs. The extraction conditions including sample solution flow rate, desorption time, acetonitrile content, pH of sample solution and sample volume were investigated. Under optimal conditions, the proposed SPME-HPLC method showed high extraction efficiency, good linearity, low limits of detection (0.2 ng/mL) and good repeatability (relative standard deviations < 2.41%). This method was also applied to the analysis of antiepileptic drugs in human plasma samples and the recoveries were in the range of 88.6-106.1% with RSDs less than 3.51%.