Figure 4. Chromatogram of reference standards.
(A) Oxalic acid; (B) Chlorogenic acid, caffeic acid and ferulic acid; (C) Gallic acid, tannin acid, vanillic acid and cinnamic acid.
(A) Oxalic acid; (B) Chlorogenic acid, caffeic acid and ferulic acid; (C) Gallic acid, tannin acid, vanillic acid and cinnamic acid.