Chiral recognition of tryptophan enantiomers based on a polypyrrole‐flake graphite composite electrode column

A polypyrrole (PPy)‐flake graphite composite was synthesized by in situ polymerization of pyrrole on flake graphite surface, and the resulting organic–inorganic composite material was developed as the conductive stationary phase in an electrode column for enantioselective recognition of tryptophan (Trp) enantiomers. Compared with the stationary phase made up with conducting PPy, the conductivity of the composite stationary phase was enhanced significantly. As a result, satisfactory enantioselectivity of Trp enantiomers can be achieved easily by modulating the potential applied on the electrode column. Various important parameters influencing the performance of the composite electrode column were investigated to obtain the optimum recognition efficiency. A recognition efficiency of 3.7 could be achieved under the optimum conditions. Enantioselectivity of the composite material for Trp enantiomers is attributed to the reversible doping/de‐doping properties of PPy.