Thermal degradation of natural dyes and their analysis using HPLC-DAD-MS

Abstract

Berberine, palmatine, alizarin, purpurin, indigotin, and indirubin which were the major coloring compounds of Phellodendron bark, madder, and indigo plant were thermally degraded in 100°C oven in liquid dye form and also in silk dyed with five of these pigments. A mixed dye solution of six coloring compounds was prepared in DMSO solution and was thermally degraded for up to 7 days. Silk were dyed using either a mixed dye solution of five dyes or individual dye solutions and each were degraded for 7 and 14 days, respectively, and the dye was extracted from the samples for the HPLC analysis. The concentration of coloring compounds in the degraded samples were analyzed by HPLC-DAD-MS and the color difference (ΔE) of the degraded silk was examined using a spectro-colorimeter. Alizarin and purpurin were more resistance to degradation than other coloring compounds both when in solution form and in silk dyeings. And such result was verified by the color difference measurement of the degraded silk dyed with individual dye solution. The resistance of alizarin and purpurin to thermal degradation was highly likely due to the fomation of fiber-metal-dye chelated complex by alum or iron mordanting before dyeing.

Thermo-oxidative and weathering degradation affecting coloration performance of lac dye

“…Although the numerous advantages have been gained from the natural dyes, the color fading due to the degradation of dye is still be one of the major problems in textile color. Normally, the color fading directly affects in the loss of intact dye molecule resulting in the change of original dye color (Ahn et al 2014). In general, the stability of natural dye is mostly influenced by the chemical and physical states of the dye.…”

“…Thermal degradation behavior of the alizarin and Phellodendron bark, alizarin and indirubin has also been studied by GC-MS and HPLC-DAD-MS (Ahn 2011;Ahn and Obendorf 2004). In addition, Ahn et al (2014) investigated the thermal resistance of the natural dyes. The thermal stabilizing performance of alizarin and purpurin was attributed to the formation of fiber-metaldye chelated complex by aluminum or iron ions mordanting prior to dyeing.…”

Eco-friendly Cotton Coloration Using Banana (Musa Sapientum) Waste: Optimization of Dyeing Temperature

“…pseudo-second order rate constant [24,25] remarkably which bolster the fashion of yielded K/S values. Thermal degradation [27] may be a probable reason of lower K/S value at 110℃.…”

“…More staining observed onto wool in case of A. For upturning temperature after 100℃ reduces the dye-fiber interaction due to thermal instability of natural pigments [27]. Table 8 illustrates the evaluation of fastness to perspiration.…”

“…So, color fastness upturns at higher temperature for stronger dye-fiber interaction [8]. But color durability properties downturns after raising temperature than 100℃ for thermal instability of natural dye molecule [27].…”