A competitive inhibition enzyme immunoassay for detection and quantification of organophosphorus compounds.

A sensitive and specific method for detection and quantification of methyl phosphonic acid, p-aminophenyl 1,2,2-trimethyl-propyl diester (MATP) as a model substance for organophosphorus compounds is described. Different procedures for coupling the haptenic group for immunization, purification and immobilization allowed the detection of hapten-specific antibodies. The competitive inhibition enzyme immunoassay (CIEIA), using purified chicken and rabbit IgG-antibodies, was able to detect MATP-concentrations as low as 10(-10) mol/l. Based upon our results, we postulate that the CIEIA represents a good alternative to the customary diagnosis of organophosphate intoxications, measuring blood cholinesterase activity.