Fig. 7
From: Chromatographic analysis of natural dyes in mediaeval Islamic paper
UV–vis spectra associated with turmeric, recorded during the HPLC–DAD analysis of: a standard curcumin (green line; retention time: 23.4 min) and sample AS16 (blue line; retention time: 22.2 min); b Bisdimethoxy- (orange line; retention time: 22.9 min) and demethoxycurcumin (yellow line; retention time: 23.2 min) in turmeric-dyed model paper, and two spectra from AS16 (Dark blue and light blue lines; respective retention times: 24.2 and 24.6 min)