Development and validation of an HPTLC–DPPH assay and its application to the analysis of honey

Using honey as a model sample, the aim of this study is to develop and validate a simple, rapid screening tool that allows for the visualization of constituents that contribute to the antioxidant activity of a complex natural product and to quantify their individual antioxidant effects even if their chemical identity is unknown. The method employs a validated analysis, which is based on the separation of constituents using high-performance thin-layer chromatography (HPTLC) followed by their visualization using DPPH* (2,2-diphenyl-1-picrylhydrazyl) as derivatizing reagent and the quantification of the antioxidant activity of individual bands expressed as gallic acid equivalents.