紫外分光光度法测定Vc含量的方法改进

目的]改进传统紫外分光光度法测定Vc含量。方法]以2,6-二氯酚靛酚滴定法为对照,对传统紫外分光光度法进行摸索、研究、改进,并确定改进方案。通过测定各种试验材料的Vc含量,对2种方法测定结果进行比较和分析。结果]在酸处理中,将原来的空白对照改为相同浓度的酸;在碱处理中,加入碱液反应15 min后不再加酸,而直接用蒸馏水定容,并将空白对照改为相同浓度的碱,所得结果与滴定法接近,且不会出现测定结果为负值的现象。结论]改进紫外法更为方便、稳定,测得的结果更加真实、可靠。

Improvement of Ultraviolet Spectrophotometry to Measure the Content of Vc

Objective] The research aimed to improve the traditional ultraviolet spectrophotometry to measure the content of Vc.Method] 2,6-dichlorophenol indophenol titration was as the control,and the traditional ultraviolet spectrophotometry was groped,studied and improved.Moreover,the improved program was determined.By measuring Vc contents of every test materials,the measured results of two kinds of methods were contrasted and analyzed.Result] In the acid treatment,the original blank control was changed into the same concentration of acid.In the alkali treatment,the acid wasn't added after the alkali reacted 15 min,but the distilled water was used directly to keep the constant volume.The blank control was changed into the same concentration of alkali.The result closed to that of titration,and the phenomenon that the measured result was the negative value couldn't appear.Conclusion] The improved ultraviolet spectrophotometry was more convenient and stable.The measured result was more real and reliable.