Development of a highly selective folic acid molecularly imprinted polymer for its determination in food extracts using dispersive solid-phase extraction and LC-MS

FERNANDEZ SANCHEZ, JORGE F.; SESAY, ADAMA M.; FERNÁNDEZ-GUTIÉRREZ, ALBERTO; MONASTERIO, ROMINA P.; PANJAN, PETER; CARRASCO-PANCORBO, ALEGRÍA; MUÑOZ DE LA PEÑA, ARSENIO

Estocolmo

Encuentro; XIX Euroanalysis 2017, Europe's Analytical Chemistry Meeting; 2017

Europe's Analytical Chemistry Meeting

Folic acid is a B vitamin-group compound of great nutritional significance. Different methodologies have been reported for its accurate determination in different matrices. Solid phase extraction or related techniques using molecularly imprinted polymers (MIPs) enable simple and effective purification and concentration of food or biological samples, thus increasing the sensitivity of the measurements and reducing possible matrix effects. Herewith, combinations of monomers (methacrylic acid (MAA), 4-vinylpyridine (4VPy) and vinylbenzyl trimethylammonium chloride (VBTMAC)) and crosslinkers (ethylene glycol dimethacrylate (EGDMA) and divinyl benzene (DVB)) have been tested in appropriate solvents. Initial isotherm tests revealed that the MIP with the highest affinity was the combination of VBTMAC and EGDMA. Having checked the appropriate template-monomer-crosslinker ratio, this FA MIP was analyzed for its kinetic and equilibrium binding properties, proving very high affinity (more than 2.5 mmol/g) and MIP/NIP ratio (up to 37). The FA MIP was used to selectively isolate the compound of interest from lettuce and cookies matrices using a dispersive solid-phase extraction protocol (which exhibited appropriate recovery and repeatability, ≥ 79.50% and ≤ 13.15 (%RDS), respectively); the resulting extracts were analyzed by a rapid LC-MS method.