KINETIC DETERMINATION OF DICOUMAROL ON GRAIN BY USING STOPPED-FLOW MIXING METHODOLOGY

A simple and fast kinetic method for the direct determination of dicou marol on grain was developed. It involves measuring the initial rate o f the colour-forming reaction (lambda = 475 nm) undergone by Gibbs' re agent in a basic medium (pH 9.0) in the presence of dicoumarol. Stoppe d-flow mixing methodology was used to obtain kinetic curves. This allo wed reagent manipulation to be minimized and the method to be automate d to some extent. The calibration graph was linear over the range 3-20 mug ml-1. Other anticoagulant rodenticides such as bromadiolone, difa cinone and warfarin are tolerated in 20-fold excess. The method was sa tisfactorily applied to the direct analysis of wheat and oat samples s piked with dicoumarol (mean recovery, 92.7%).