the blue color is formed by
TPC = Cs.
Aa
As
L. B. D. C. Araújo et al. / Rev Bras Farmacogn 23(2013): 736-742 739
Liebermann-Burchard reagent optimization
The addition of excess acid by increasing the amount of
Liebermann-Burchard reagent resulted in decreased overall
phytosterol content. This was observed after 2 ml of the
Liebermann-Burchard reagent was added to the samples (Fig. 3)
an oxidation reaction, from pentacyclic cations (Brieskorn
and Hofmann, 1964; Sorensen, 1965; Xiong et al., 2007; Yoder
and Thomas, 1954). The maximum observed for the blue
oxidation product occurs at 625 nm