New Solid Phase Materials for Phytoanalytical Purposes

Solid phase extraction (SPE) is a powerful tool for analytical chemists in the fields of extraction, purification and enrichment. The aim of this work is focused on the development of new solid phase extraction materials for the preconcentration and purification of pharmacologically active components out of different plant materials. Special interest is put on molecules with phenolic and polar functions like oleuropeine due to their positive effects on human health.

By now, almost all commercially available SPE-Materials are either hydrogencarbon derivatised spherical silica particles or polymers which are in general adequate for most analytical purposes but not sufficient in all cases of complex analytes or difficult matrices. In this approach, the surfaces of different substrate materials, diamond powder, titan oxide, porous and non porous silica gels, are coated by radical polymerisation with different mixture ratios of functionalised phenols and divinylbenzene to achieve strong π -π and OH interactions between analyte molecules and stationary phases during concentration and cleaning progress [1]. Therefore not only the influence of different kinds of bulk material and their morphology but also the different ratios of the coating monomers on extraction efficiency are investigated.

Scanning electron microscopy (SEM) investigations are proving the successful surface coatings and are showing different morphologies depending on the bulk materials. The materials are tested with standard mixtures, with real samples of olive oil and olive leave extracts. The recovery results are compared to commercially available SPE materials with special focus on the extraction of phenolic targets like oleuropein.

References: [1] M. Sultan, et al., (2005) Curr. Med. Chem. 12: 573–588