The content of p-N-oxalyl-L-a,p-diaminopropionic acid (P-ODAP) in thirty grass pearnseed samples were determined by a FI system incorporating a glutamate oxidasernreactor. The assay of p-ODAP was made via the oxidation product, hydrogenrnperoxide, which was detected spectrophotometrically at 512 nm using Trinderrnchromogenic reagent. The same samples were assayed by the Rao's modifiedrncolorimetric procedure at 476 nm. The concentrations obtained by the enzymaticrnmethod was 10-50% higher than that obtained by the colorimetric method. Thernresults of another variation of Rao's method (Campbell procedure) was 53-66% lowerrnthan that of the FI method.rnSeparations of proteins from p-ODAP in grass pea extracts were made by twornprecipitation methods with trichloroacetic acid (1 %) and perchloric acid (0.46%) andrnby ultrafiltration. Sample injections of glucose spiked extracts after the three samplernclean-up procedures enhanced stability of glucose oxidase reactors in a FI system.rnThe response of a FI system with a small GOD reactor to glucose-spiked crudernextract gradually decreased to zero after 36 injections.rnSynthesis and characterization of sulphonated 2,4-dichloronaphthol, as substituternfor 2,4-dichlorophenol-6-sulphonate in Trinder reagent, was studied. The molarrnabsorptivities for hydrogen peroxide at 512 nm P.max) were 15,220 and 11,380 MÂ·jrncmÂ·j at pH 4.2-5 and at pH 7 respectively. This reagent was used in therndetermination of hydrogen peroxide and glucose in both batch and flow injectionrnsystems