IMPRINTED DISPERSION POLYMERS - A NEW CLASS OF EASILY ACCESSIBLE AFFINITY STATIONARY PHASES

Non-stabilizing dispersion polymerization in combination with molecular imprinting was used to prepare agglomerates of globular micron-sized particles exhibiting molecular recognition properties. These could be prepared either in situ in a chromatographic column or separately followed by wet or dry packing of the material. This allowed a rapid chromatographic evaluation of the molecular recognition properties of the materials. Depending on the monomer concentration and the solvency of the dispersion medium the particle dispersity, the degree of particle agglomeration and the average particle size varied. The choice of dispersion medium was mainly dictated by the template solubility and the nature of the interactions between the functionalized monomers (methacrylic acid) and the template used for producing the molecular recognition sites. Addition of water to the dispersion medium allowed imprinting of the poorly soluble template pentamidine (PAM), a drug used for the treatment of AIDS-related disorders. The PAM-imprinted materials prepared in situ in the chromatographic column strongly retained the drug in the chromatographic evaluation compared to the retention of PAM on a reference material prepared using benzamidine as template (separation factor alpha' = 6.8). Meanwhile weakly or moderately basic templates from the group nucleotide bases (tri-O-acetyladenosine), herbicides (atrazine) and chiral amino acid derivatives (L-phenylalanine anilide) required low temperature and exclusion of water during imprinting in order to produce the recognition effect.