Quantification of Protocatechuic Acid in Hibiscus sabdariffa Collected in Vietnam by HPLC-PDA

Hibiscus sabdariffa L. (H. sabdariffa), a member of the Malvaceae family commonly referred to as “roselle,” is widely utilized in traditional medicine for its sour taste and cooling properties, as well as due to the common belief that it acts on the liver and large intestine meridians. Despite its widespread use, standardized quality control parameters for this medicinal plant remain unavailable in Vietnam. For this study, H. sabdariffa calyces were collected and subjected to quantitative analysis for protocatechuic acid (PCA), a phenolic compound that contributes significantly to the plant’s pharmacological activity. Chromatographic separation was performed using a Phenomenex Gemini C18 column (250 mm × 4.6 mm; 5 μm) and a photodiode array (PDA) detector. The column was maintained at 30°C, with an injection volume of 10 µL and a detection wavelength of 260 nm. The mobile phase comprised solvent A (0.1% trifluoroacetic acid in water) and solvent B (acetonitrile), delivered at a flow rate of 0.6 ml/min. The calibration curve exhibited excellent linearity (R² > 0.995), and the method demonstrated good precision, with intra- and inter-day variations of less than 6%. The recovery rates ranged from 90.01% to 100.05%, indicating acceptable accuracy. Overall, the validated high-performance liquid chromatography (HPLC) method was simple, robust, and reliable for quantifying PCA in H. sabdariffa. This approach is also suitable for quality control processes and establishing standardized specifications for H. sabdariffa in Vietnam.