A reversed-phase liquid chromatographic method was developed for the assay of synephrine in Citrus aurantium dry extract. The chromatographic separation used a C18 (250 × 4.6 mm, 5 µm) column and a mobile phase consisting of acetonitrile: 0.01% orthophosphoric acid (pH 3.0) at a 15:85 ratio, flow rate of 1 mL min-1 and detection at 220 nm. The detector response was linear in the range 15 - 45 mg mL-1. Specificity and stability, indicating suitability of the method, were confirmed using stress conditions (acid and basic hydrolysis, oxidation and photolysis). Intraday precision yielded RSD values of less than 1.77% and interday precision of 2.5%. The average recovery accuracy of the test was 102.03%. The method was validated according to international guidelines and can be used in routine quality control and stability studies of Citrus aurantium preparations. The preliminary stability study showed that synephrine is susceptible to hydrolysis, oxidation and photolysis.
Citrus aurantium ; synephrine; HPLC-PDA; stability
