Abstract

JIMENEZ DIAZ, Manuel. Modificación de un método para colinesterasa plasmática empleando la reducción del ferricianuro como indicador. Rev. costarric. cienc. méd [online]. 1999, vol.20, n.1-2, pp.17-27. ISSN 0253-2948.

A kinetic method for the determination o serum cholinesterase is presented. Th hydrolysis of propionyithiocholine liberates thiocholine, that reduces yellow ferricyanide to colourless ferrocyanide The decrease in absorbance at 405 nm is proporcional to enzyme activity. The CV of the between run precision range from 1,2 to 3,2 per cent. Within-run precision ranged from 0,52 to 1,1 per cent. Bilirrubin do not interfere up to 15 mg/dL and 50 mg/dL hemoglobin cause an interference of -4 percent. The working reagent, stored in an amber-colored bottle, is stable for at least 3 months at room temperatura and 6 months at 4-8°C. Comparisons with results by a commercial method based on the Ellman's reaction gave a linear regression of Y = 1,23 (X) - 732, with a correlation coefficient (r) of 0.988 and a standard error (Sy/x) of 378 U/L.

Keywords : serum cholinesterase; organophosphates; carbamates; pesticides; colorimetric methods; toxicology.