A high-performance thin-layer chromatography method for the simultaneous determination of quercetin and gallic acid in Eclipta alba and Guiera senegalensis

Eclipta alba and Guiera senegalensis have traditionally been used in Ayurvedic and Unani medicine to cure several ailments. Due to the high demand, the quantitative standardization of plant-based products is challenging to maintain their quality. We aimed to develop and validate a high-performance thin-layer chromatography (HPTLC) method for the simultaneous detection and quantification of gallic acid and quercetin in E. alba and G. senegalensis, respectively. Aqueous extracts of both plants were prepared. Qualitative and quantitative analyses were performed for the simultaneous separation of gallic acid and quercetin in each extract as per the International Conference on Harmonization (ICH) guidelines with respect to linearity, specificity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ) and robustness. HPTLC quantitative analyses for E. alba aqueous extracts revealed 3.83 mu g/mg of gallic acid and 2.26 mu g/mg quercetin, while 4.71 mu g/mg of gallic acid and 1.06 mu g/mg of quercetin for G. senegalensis. LOD was found to be 3.30 ng/band and 12.70 ng/band, while LOQ was found to be 10.20 and 38.60 ng/band for gallic acid and quercetin, respectively. The HPTLC method showed good linearity, recovery and robustness of the validated markers. This developed validated method is capable of quantifying and resolving gallic acid and quercetin and the quality control of E. alba and G. senegalensis.