Abstract
A spectrophotometric method was developed and validated for choline in enteral nutrition. The method involves an enzymatic conversion of choline by choline oxidase to hydrogen peroxide, which reacts with 3-(N-ethyl-3-methylanilino)-2-hydroxypropanesulfonic acid (TOOS) and 4-aminoantipyrine in the presence of peroxidase to form a purple colored product with the optimal absorption at 554 nm. The test conditions were optimized for avoiding interference by any active ingredient other than choline in a commercial drug product (ELENTAL®). This method was validated for the determination of choline bitartrate in the ELENTAL®, and demonstrated good specificity, linearity, accuracy and precision. The proposed method was successfully applied to assays of choline in commercial drug products (ELENTAL® and HEPAN ED®). The proposed method is simple, specific and useful for the determination of choline in enteral nutrition and supplements.
