Chemiluminescent assays for choline and phospholipase-D using a flow injection system

A flow injection chemiluminescent method is described for the determination of choline. The method is based on the production of hydrogen peroxide from choline using on-line covalently bound immobilized choline oxidase column. The product is mixed downstream and detected via the cobalt catalyzed chemiluminescent oxidation of luminol. The detection limit is 1 x 10(-7) mol/L, with rsd 1.8 to 2.8% in the range 2-10 x 10(-5) mol/L. The sample throughput is 30 per hour. The method was applied to the determination of choline produced off-line from phosphatidylcholine using phospholipase-D isolated from cabbage.