天然靛蓝和合成靛蓝染色棉织物的鉴别

Identification of Cotton Fabrics Dyed with Natural and Synthetic Indigo

研究了3种快速鉴别天然靛蓝与合成靛蓝染色棉织物的方法,通过薄层色谱测试、化学试剂氧化测试以及可见光吸收光谱测试,发现了天然靛蓝与合成靛蓝染色棉织物的显著差异。结果表明:经薄层色谱测试,天然靛蓝染色棉织物出现了蓝色(Rf=0.78)和紫红色(Rf=0.55)色斑,而合成靛蓝染色棉织物仅出现了蓝色(Rf=0.78)色斑;经浓硝酸氧化测试,天然靛蓝染色棉织物由内到外出现淡紫红色、黄绿色两个色圈,经水洗后仅剩下紫红色色圈,而合成靛蓝染色棉织物由内到外出现淡黄色、黄绿色两个色圈,经水洗后色圈全部消失;经可见光吸收光谱测试,天然靛蓝染色棉织物同时在563nm和610nm处出现吸收峰,而合成靛蓝染色棉织物仅在610nm处出现吸收峰。

This paper studies three methods for rapid identification of cotton fabrics dyed with natural and synthetic indigo and finds significant differences of cotton fabrics dyed with natural and synthetic indigo through thin／｜layer chromatography test,chemical reagent oxidation test and visible light absorption spectrum test.The result shows：according to thin ／｜layer chromatography test,cotton fabrics dyed with natural indigo have blue（Rf=0.78） and amaranth（Rf=0.55）colored patches,while cotton fabrics dyed with synthetic indigo only have blue（Rf=0.78）colored patches;according to concentrated nitric acid test,cotton fabrics dyed with natural indigo have light amaranth and yellow green color circles and only amaranth color circle remains after washing;however,cotton fabrics dyed with synthetic indigo have light yellow and yellow green color circles and all color circles disappear after washing;according to visible light absorption spectrum test,cotton fabrics dyed with natural indigo have absorption peak at 563nm and 610nm simultaneously,but cotton fabrics dyed with synthetic indigo only have absorption peak at 610nm.