Enzymatic determination of alpha-aminophosphonates with butyryl cholinesterase and carboxylesterase

The analytical characteristics of the determination of ox-aminophosphonates were studied using butyryl cholinesterase from horse serum and microbial c arboxylesterase stabilized by incorporation in water-soluble N-phthalylchit osan-based polymeric films. It was demonstrated that the compounds under st udy exhibited only a slight reversible inhibiting effect; however, their ox idation with electrochemically generated chlorine resulted in an irreversib le inhibiting effect, which became more pronounced in an acidic medium. Wit h the use of carboxylesterase, whose activity hardly depended on the pH of the medium and the action of ionic effecters, allowed the limits of detecti on (LOD) for alpha-aminophosphonates to be lowered by a factor of 1.5-10 (d own to 10(-8) M) compared to those obtained with cholinesterase.