Figure 1From: Thermal degradation of natural dyes and their analysis using HPLC-DAD-MSHPLC-DAD chromatogram of the mixed dye solution before degradation treatment. Numbers in the chromatogram indicate; 1 berberine, 2 palmatine, 3 alizarin, 4 purpurin, 5 indigotin, 6 indirubin (reproduced from Ahn et al., 2014).Back to article page