In the determination of p-ODAP by flow injection analysis using a glutamate oxidasernreactor , the major problem is that proteins and other macromolecules cause a rapid decay of thernactivity of the reactor when an extract of grass pea is directly injected into the reactor.rnIn this work, off-line and on-line protein separation is described. In a preliminary study,rna standard protein sample, bovine serum albumin (BSA), was treated with acidic alumina atrndifferent pH. Excess BSA was washed and the absorbance of the supernatant was taken at 280rnnm. It was found that 84% of the protein was adsorbed on alumina at pH 7 (off-line separation).rnThe recovery of p -ODAP was also studied at different pH by treating it with the alumina .rnAbsorbance at 220 nm, before and after its treatment with the alumina revealed 100Â± 5% recoveryrnat pH 7 .rnBSA and p -ODAP were combined and treated with alumina to check whether theirrncoexistence has an effect on their interaction with alumina. Since P-ODAP may interfere with thernmeasurement carried at 280 nm , the amount of the adsorbed protein was quantitated at 750 nmrn( Lowry -Folin method) and found to be 85% which is in a good agreement with the resultrnobtained when the measurement of BSA was carried alone (84% ).rnThe strong anion exchanger (SAX), trimethylaminopropyl Isolute SAX(500-0010A), wasrnemployed for on-line separation of proteins. Of the injected standard protein and those fromrnextracts of grass pea, 98% were retained by the sample clean-up column at a pH of 6.5 . Thisrnindicates that effective removal of proteins was achieved . The sample clean-up column has nornsignificant effect in retaining P-ODAP and 98 % of the injected standard P -ODAP was recovered .