天然彩色棉纤维色素提取及光谱特性研究

 以白色棉、绿色棉、棕色棉成熟纤维为材料，选用氯仿、乙酸乙酯、乙酸乙酯-乙醇（1：1）、乙醇、蒸馏水等5种不同的中性溶剂，分别对经石油醚脱脂后的不同颜色纤维中色素进行提取。结果表明，绿色棉纤维色素乙酸乙酯-乙醇（1：1）提取效果最好，棕色棉纤维色素蒸馏水提取效果最好；绿色棉纤维色素乙酸乙酯-乙醇（1：1）提取液有3个吸收峰，由弱到强分别在252 nm、300 nm和328 nm，其色素随相对浓度减小，光吸收值相应变小，300 nm和328 nm处吸收峰的光吸收值与浓度的变化有明显的线性关系；棕色棉纤维色素蒸馏水提取液在237 nm处有1个吸收峰，其色素随相对浓度的减小，光吸收值也相应变小，但吸收峰迅速向紫外短波长方向移动。

Study on Extraction Method and Spectral Properties of Pigment in Naturally Colored Cotton Fibers

Pigment in the mature fiber of green fiber and brown fiber defatted with the petroleum ether was extracted by five kinds of neutral solution (chloroform，ethyl acetate，ethyl acetate–ethanol(11), ethanol and distilled water). The result showed that the extraction of pigment in natural green fiber by using ethyl acetate–ethanol (11), while that in natural brown fiber by using distilled water was the most effective, respectively. The UV spectrum characteristic of the pigment of natural colored cotton was analyzed. There were three absorbance peaks for green pigment at 252 nm, 300 nm and 328 nm, respectively. There was a linear relationship between the absorbance value and its relative concentration at 300 nm or 328 nm. The brown pigment from distilled water distillation had a maximum absorbance peak at 237 nm, but the spectrum of absorbance peak moved to shortwave with the pigment concentration’s declined.