Determination of dicoumarol in Melilotus officinalis L. by using molecularly imprinted polymer solid-phase extraction coupled with high performance liquid chromatography.

In this work, a method for the extraction of dicoumarol from plant sample utilizing selective adsorbent based on molecularly imprinted polymer was developed. Molecularly imprinted polymer (MIP) was synthesized by bulk polymerization, and on the surface of magnetic particles using dicoumarol as a template, methacrylic acid as functional monomer, chloroform as a porogen, and ethyleneglycol dimethacrylate as a cross-linker. Prepared polymeric materials were evaluated on the base of capacity, selectivity, and morphology. The maximal specific adsoption capacities of the sorbents were 45 μg (for bulk MIP) and 36 μg (for MIP on the magnetic particles) of dicoumarol per 1 g of polymer. An efficiencies of sorption processes of dicoumarol on prepared sorbents were evaluated under various conditions (type of sample solvent, pH, types of washing and elution solvents). The MIP based sorbents were used for solid phase extraction of dicoumarol. Applicability of MIP-SPE coupled to HPLC-DAD was tested for the selective extraction of dicoumarol from sample of sweet clover. The method was linear over concentration range from 1 to 100 μg mL-1 (the correlation coefficient 0.9984) with limit of detection 0.2 μg mL-1. Accuracy of the method was assessed for spiked sample at three concentration levels and recovery values were higher than 84% with relative standard deviation lower than 3.2%.