Preparation of molecularly imprinted polypyrrole/Fe3O4 composite material and its application in recognition of tryptophan enantiomers

Abstract

Ferrosoferric oxide Fe3O4 magnetic material was first synthesized and then the in-situ chemical polymerization of pyrrole was carried out on the surface of Fe3O4 by using pyrrole and L-tryptophan L-Trp) as the functional monomer afid templates respectively. As a result; molecularly imprinted polypyrrole/Fe3O4 composite material was obtained. This composite material was separated from the solution bec-iiise of its magnetic property. Polypyrrole in the composite was overoxidized in 1 mol/L NaOH solution by applying a potential of 1.0 V and thus L-Trp templates were de-doped from the composite. Scanning electron microscopy(SEM) X-ray diffraction(XRD) and electrochemical methods were employed to characterize the composite. The solution containing L-or D-Trp was pumped through a porous ceramic tube packed with the composite separately. High performance liquid chromatography(HPLC) was adopted for the detection of"L-or D-Trp in the eluate and the results indicated that the enrichment ability of the composite for L-Trp was almost 2 times of that of D-Trp. Therefore; the electro-magnetic composite material has potential applications as chromatographic stationary phase for chiral recognition. © 2010 Editorial Office of Chinese Journal of Chromatography, Dalian Institute of Chemical Physics, CAS.