Comparison of different types of sorbents for extraction of coumarins.

Abstract

Coumarins, derivatives of cinnamic acid, are found in wines aged in wooden barrels. The lab-made molecularly imprinted polymers (MIP), selective for simple coumarins, were used in three forms, as sorbents in solid phase extraction (SPE) cartridge or pipette tip and coated on to the surface of magnetite for magnetic extraction. MIP-7-hydroxycoumarin had greater selectivity and extraction efficiency (recoveries above 75%, RSDs less than 6%) compared with conventional SPE sorbents (C18 and styrene-divinylbenzene polymeric types). Batch extraction with MIP coated on to magnetic particles was relatively time-consuming compared with conventional and pipette tip SPE. The advantage of pipette tip SPE was reduced solvent volumes. LOQs for MISPE offline coupled with HPLC were less than 1.5µgmL-1 and 12ngmL-1 for UV and fluorescence detectors, respectively. 6-Methoxy-7-hydroxycoumarin and 4-methyl-7-hydroxycoumarin were detected in Slovak Tokaj wines using method with coumarin-specific sorbents.