Phosphatidylcholine determination in dietary supplement by coupled enzymes immobilized in a single bioreactor

Abstract A rapid and selective method for the determination of phosphatidylcholine (PC) is described. It is based on the use of a single packed bed reactor in which phospholipase C, alkaline phosphatase and choline oxidase are co-immobilized on long chain-alkylamino controlled pore glass. The detection of hydrogen peroxide, that is the final product of subsequent enzymatic reactions occurring within the bioreactor, is used for the determination of PC in a dietary supplement. The results of triplicate analysis show a coefficient of variation of 5%. The calibration curve is linear over a concentration range of 10–60 mg/L (R 2 = 0.942) and the detection limit is 4.25 mg/L. The bioreactor resulted to be stable for at least 1 month.