Investigating Flavonoids by HPTLC Analysis Using Aluminium Chloride as Derivatization Reagent.

This is the first study to report on high performance thin layer chromatography (HPTLC) generated spectrophotometric data to systematically capture flavonoid compounds using optimized derivatization with either AlCl or NaNO-AlCl-NaOH as visualisation reagents. While the traditional AlCl colorimetric method using UV-Vis analysis provides valuable insights into the presence of flavonoids and allows derivation of the total flavonoid content (TFC) of a sample, HPTLC fingerprints obtained after spraying with AlCl or NaNO-AlCl-NaOH enable the visualization of the various flavonoids present in a sample based on their respective absorption shifts, thus complementing the traditional TFC assay. In this study, 40 different flavonoids representing different classes (flavonols, flavanolols, flavan-3-ol, flavones, flavanones, and isoflavonoids) were analysed.