Investigation of Acid-Base Indicator Property of Plumbagin from Plumbago zeylanica Linn

Figure 2

UV spectra for plumbagin in different pH media. (a) Plumbagin in methanol. Absorption occurs at 265 nm (λ_max) and 410 nm. (b) Plumbagin in acidified methanol. Absorption takes place at 248 nm (λ_max) and 420 nm from hypsochromic shift. (c) Plumbagin in basified methanol. Absorption takes place at 275 nm (λ_max) and 520 nm from bathochromic shift.

(a)

(b)

(c)