无毒紫外吸收剂的脱色及光谱特性分析

用多种脱色剂对从芒果树叶中提取的紫外吸收剂进行脱色,并对脱色后的紫外吸收剂进行光谱特性分析.通过对光谱特性分析结果的比较,探索天然紫外吸收剂的脱色方法.结果显示,以活性炭、过氧化氢、柠檬酸、草酸作为脱色剂,都有较好的脱色效果.以草酸作为脱色剂所得到的脱色产物色泽浅、收率高,脱色后的紫外吸收效果与脱色前差别不大,浓度为0.5%(w/w)的溶液,在200～370nm的范围内相对紫外透射率均小于0.3%,从370 nm开始,透射率有所增加,最大值出现在400 nm处,接近12%.

Decoloring and Spectral Properties Analysis of Innoxious Ultraviolet Absorbents

The ultraviolet absorbent extracted from mango leaves,was discolored by some decoloring agent.Then the spectral properties of the discolored ultraviolet absorbents were analyzed.The discolored method of ultraviolet absorbent was studied by comparing one with the others.The results showed that the discoloring effect was satisfactory by using active carbon,H_2O_2,citric acid,and oxalic acid as decoloring agent.Specially,when oxalic acid was used as decoloring agent,the color of the production was slight,the rate of production was high,and the absorption effect of ultraviolet ray was well.When the concentration of the ultraviolet absorbent solution is 0.5%(w/w),the ultraviolet ray transmission was smaller than 0.3% in 200-370 nm,and it increased slightly from 370 nm.There was a maximum value at 400 nm,approaching 12%.