Preparation and evaluation of molecularly imprinted polymer of olivetol for solid phase extraction

Molecularly imprinted polymer (MIP) was synthesized by bulk polymerization, using olivetol as template molecule, methyl acrylic acid (MAA) as monomer, ethylene glycol dimethacrylate (EDMA) as crosslinker, toluene and dodecanol as solvents. The resulted MIP was characterized by the equilibrium binding experiments, scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). The polymer was then applied to solid phase extraction (SPE) of olivetol from spiked wheat bran samples. From the equilibrium binding experiments, it was showed that MIP had a better recognizability for the template molecule. Scatchard analysis showed that MIP had specific adsorption to olivetol with two classes of binding sites. The high and low binding sites dissociation constants were 0.021 and 1.002 mmol/L. The corresponding maximum binding capacities were 18.74 and 135.9 micromol/g, respectively. Under the optimum condition of SPE, the recoveries of olivetol on MIP cartridge were in the range of 97.8% - 98.8%. The relative standard deviations (RSDs) were 2.8% -4.2%. The linearity range was between 0.1 and 100 mg/L. The limit of detection (S/N = 3) was 0.062 mg/L. MIP cartridge showed stronger selectivity, higher recovery and purified the sample more drastically compared with non-imprinted polymer (NIP) cartridge and commercial poly (styrene/divinyl-benzene) (PLS) cartridge.