Antioxidant activity of E. arvense extracts. (A) A TLC plate developed in DPPH reagent, viewed under white light. Pink/purple regions are unreacted DPPH, lighter regions are where the DPPH radical has been scavenged by an antioxidant. After, dipping the TLC plate was left for 10 min for the reaction to proceed fully and intentionally “over-exposed” to reveal weak differences in radical scavenging. Rf: relative front. (B) A representative chromatogram of the China 8 sample using the on-line DPPH assay. The chromatogram at 280 nm (black line) is overlaid with the DPPH absorbance at 515 nm (red line). Compounds that have DPPH antioxidant activity are observed as a negative peak at 515 nm. (C) A comparison between the antioxidant abilities of each of the E. arvense extracts using the DPPH, FCR and ORAC assays.