EFFECT OF METAL-IONS ON THE COLORIMETRIC DETERMINATION OF IRREVERSIBLE CHOLINESTERASE-INHIBITORS

Colorimetric tests based on cholinesterase preparations stabilized by N-phthalylchitosan were developed. They determine organophosphorus irr eversible inhibitors in the concentration range n x 10(-8)-n x 10(-7) M (Diazinon, Zolone, Carbophos, Co-ral, and Metaphos) or n x 10(-7)-n x 10(-5) M (DDVP) with the use of an AKI-Ts-01 analyzer Test character istics depend on the nature of the substrate (butyrylcholine iodide or indophenyl acetate) and on the presence of reversible effecters (copp er and aluminum salts), which impair the inhibiting effect of organoph osphorus compounds. N-Phthalylchitosan affects the sensitivity of chol inesterase to reversible and irreversible inhibitors. This effect may be associated with the formation of stabilizer-metal or stabilizer-enz yme-metal complexes.