ABSTRACT
Trichloronate is a racemic organophosphate, which has been used for the manufacture of insecticides. This compound induces delayed neuropathy in hen and humans. This study shows the Cu2+-dependent hydrolysis of trichloronate by turkey serum using UV/Vis spectrophotometry and chiral chromatography. The CHIRALCEL OD column and mobile phase of heptane allowed a resolution of 1.15 of its two enantiomers, while the liquid-liquid extraction showed a recovery of 95-98%. The optimum linear response was of 50 to 800⯵M with a detection and quantification limit of 0.6 and 2⯵M for (+)-trichloronate, and 0.7 and 2.3⯵M for (-)-trichloronate. The levels of Cu2+-dependent hydrolysis (µM remaining concentration) quantified for 60â¯min at 37⯰C and pHâ¯7.4 were statistically higher (pâ¯Ëâ¯0.05) for (-)-trichloronate (65%) than (+)-trichloronate (32%). This stereoselective hydrolysis was confirmed by UV/Vis spectrophotometry using 2,4,5trichlorophenol as standard, each of the enantiomers (93-95% purity) collected by HPLC, as well as aminoantipyrine and ferricyanide reagents to yield a colored product. This method exhibited an optimal linearity (râ¯>â¯0.99) and a higher Cu2+-dependent hydrolysis (pâ¯<â¯0.05) to (-)-trichloronate (47%) than its corresponding (+)-form (31%). This results shows the Cu2+-dependent stereoselective hydrolysis of a racemic OP in its thio form (Pâ¯=â¯S) by an A-esterase of the turkey serum through the development of a colorimetric method and optimization of an existing chiral chromatographic method.