Study of acetylcholinesterase inhibitors using CE with contactless conductivity detection

The hydrolysis of acetylcholine and acetylthiocholine as catalyzed by the enzyme acetylcholinesterase was monitored by CE with contactless conductivity detection by determining the acetate produced in the reaction. This approach eliminates the need for a color forming derivatization procedure. The effects of the three inhibitors galanthamine, hyperzine A and paraoxon on the enzyme kinetics could also be investigated by the new procedure and the IC(50) values were determined. The contactless conductivity detection was also found to be compatible with the electrophoretically mediated microanalyis approach, in which the enzymatic reaction is carried out directly inside the capillary prior to separation and quantification.