Identification and quantitation of Choline in food supplements using high performance liquid chromatography

A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the separation and quantitative determination of choline in dietary supplements. The method optimization involved the selection of a Purospher C18 column and an acetonitrile:water (75:25, v/v) mobile phase, with detection at 205–208 nm. Validation followed ICH Q2 guidelines, assessing specificity, linearity, accuracy, precision, and sensitivity. The method demonstrated excellent linearity (R² > 0.9900) over the range of 50–150 µg/mL, with recovery rates between 99.3% and 101.0%. The limit of detection and quantification were determined to be 4 µg/mL and 12 µg/mL, respectively. Application of the method to both pure choline and commercial multicomponent dietary supplements showed that drying choline prior to analysis is necessary for reliable results. The method provided consistent quantification of choline in supplements, with measured amounts closely matching label claims, and the largest deviation observed was approximately 7 milligrams. This RP-HPLC method is suitable for routine quality control of choline in dietary supplement formulations.