Validation of different commercially available cholinesterases for pesticide toxicity test

A systematic study of different commercially available cholinesterases (AChEs from electric eel, human erythrocytes, bovine erythrocytes and BuChE from horse serum) for the FIA determination of some frequently used organophosphate (paraoxon, oxydemeton-methyl, triazophos, diazionon) and carbamate (carbofuran, propoxur) pesticides was carried out. Responses of the previously developed photothermal FIA system were found to be dependent on the origin of cholinesterases and properties of tested pesticides. The highest sensitivity was obtained with electric eel AChE and the lowest sensitivity with horse serum BuChE. The LOD values for investigated pesticides correlate with acute toxicities expressed as LD50 (oral, rat). The presented FIA system could serve as an alternative screening test to evaluate the toxicity of different environmental samples, new cholinesterase inhibiting pesticides or other products (e.g. nerve gases).