Qualitative And Quantitative Analysis Of Pigment Components In Cotton

Natural colored cotton do not need to be dyed in the process of processing,so its processing route is short,the cost is reduced,and the environmental pollution is also reduced.Moreover,chemical additives and synthetic dyes added in the dyeing process do not remain in the colorful cotton products.Natural colored cotton is called green textile material.Although natural colored cotton has a long history of cultivation,natural colored cotton has been gradually eliminated in the development process because of its short fibers,poor strength,and difficulty in textiles.Until the concept of consumer consumption changed in recent years,people began to pay attention to the process of textile production and use.In the pollution problem,natural colored cotton had been seen due to its green and environmental features.Therefore,it is necessary to further study the various characteristics of natural colored cotton and provide basis for the further development of natural colored cotton.This thesis mainly studied the pigment composition,content,stability of na tural colored cotton.Firstly,the effects of pH value,temperature and different metal ions on the color stability of natural colored cotton were studied by a c omputer color measurement color matching instrument.The experimental results show that:the color of natural colored cotton will change obviously when it encounters strong alkali or strong acidic substances;the color of natural colore d cotton will also change with the increase of temperature;in the metal ions,Fe3+has the greatest influence on the color of the colored cotton products,an d Na+has less influence.Secondly,the pigment components in green cotton,b rown cotton and white cotton pigment extracts were analyzed by means of UV spectrum analysis,infrared spectrum analysis,X-ray diffraction spectrum analy sis and liquid chromatography mass spectrometry analysis.The experimental resu lts show that the pigment component of cotton fiber is flavonoids.The flavono ids in brown fiber pigments are apigenin-7-(6’’-crotonoyl glycoside),pendulin,s cutellarin,and subtrunsanthin,et al.The flavonoids contained in the pigment co mponent of green cotton fiber are rutin,quercetin,Piscerythramine,apigenin-7-(6’’crotonoside),kaempferol 3[6’’-(3-hydroxy-3)-methylglutaryl)glucoside,puer arin,et al.The flavonoid compounds contained in the white cotton fiber pigmen t component are kaempferol 3-(3’’,4’’-bisbisacylglucoside),scutellarin,baicalin e t al.Finally,the rutin standard curve was drawn with different concentrations o f rutin standard solution,and the regression equation of rutin standard curves was:Ar=0.0326W+0.0652,correlation coefficient:R~2=0.9947.The content of flavo noids in cotton fiber pigment extract was determined by direct determination in spectrophotometry.The experimental results show that the content of flavonoid s in natural green cotton is 105~136ug/ml,the content of flavonoids in natural brown cotton is 16~36ug/ml,and the content of flavonoids in natural white c otton is 10~23ug/ml.