Figure 2From: Thermal degradation of natural dyes and their analysis using HPLC-DAD-MSUV-Visible absorption spectra (left) and mass spectra (right) obtained through the HPLC-DAD-MS analysis on the mixed dye solution before degradation treatment. Numbers on the left indicate; 1 berberine, 2 palmatine, 3 alizarin, 4 purpurin, 5 indigotin, 6 indirubin.Back to article page