天然彩棉棕色素定量测定方法的建立

Establishment of a New Determination Method for the Pigment of Natural Colorful Cotton

本文首先对彩棉棕色素的纯化方法作了改进,在此基础上,分别测定和分析了:①纯化色素水溶液的UV光谱性质;②在pH10.0的NH3-NH4Cl缓冲溶液条件下,棕色素的可见光谱以及色素相对浓度和510nm处光密度的数量关系;③含有杂质没有经过纯化的棕色素,在pH10.0的NH3-NH4Cl缓冲溶液条件下,在510nm处吸光度平均值与相对浓度的数量关系。结果发现:①纯化色素水溶液的UV光谱受pH值的影响而有所不同;②在pH10.0的条件下,纯化色素水溶液的UV光谱在波长510nm处有1个小的吸收峰;③在pH10.0的NH3-NH4Cl缓冲溶液条件下,棕色素可见光谱在波长510nm处同样有1个小的吸收峰;④纯化色素510nm吸光度与相对浓度成线性关系,其回归方程为y=0.033x,R2=0.9923,二者的相关系数0.9983;⑤在pH10.0的NH3-NH4Cl缓冲溶液条件下,含有杂质没有经过纯化的棕色素,在510nm吸光度平均值与相对浓度也表现线性关系,回归方程为y=0.0395x,R2=0.9926,二者的相关系数0.9898。据此我们建立了分光光度法直接测定色素粗提液中色素含量的方法,通过重复性试验和统计学分析表明,本实验简便且精确度较高,完全符合实验的需要。标准差SD=1.8528×10-5,光密度平均值X=0.1516,变异系数CV=1.22×10-4。本方法的建立,对彩色棉的纤维色泽遗传规律的深入研究和棕色棉的育?

The method for purifying the pigment of natural colorful cotton was imp roved at first. On this basis, the following spectra were determined or quantita tive relationship was analyzed: ①The UV spectra of the H2O solution of the puri fied pigment. ②The visible spectrum of the pH10.0 NH3-NH4Cl buffer solution of the purified pigment and the quantitative relationship between values of optical density at 510nm and its relative concentration of the purified pigment. ③The quantitative relationship between values of optical density of the unpurified pi gment at 510nm and its relative concentration in the pH10.0 NH3-NH4Cl buffer sol ution. Found out:① The UV spectra of the H2O solution of the purified pigment w ere affect by pH values. ②There was a small absorption peak at 510nm in the spe ctrum of the pH10.0 H2O solution of the purified pigment. ③There was a small ab sorption peak at 510nm in the visible spectrum of the pH10.0 NH3-NH4Cl buffer so lution of the purified pigment too. ④There was a linear relationship between op tical density of the purified pigment at 510nm and its relative concentration, w ith the regression equation: y=0.033x,correlation coefficient: y=0.9983, and R2= 0.9923. ⑤There was a linear relationship between optical density of the unpurif ied pigment at 510nm and its relative concentration in the pH10.0 buffer solutio n too, with the regression equation: y=0.0395x,correlation coefficient: y=0.9898 , and R2=0.9926. So a new determination method for the unpurified pigment was set up accord ing to the UV spectrum characteristics. The new method is convenient and accurac y verified by repeated experiments and statistic test, with SD(the standard devi ation)=1.8528×10-5,CV(coefficient of variation)=1.22×10-4,and the average of o ptical density X=0.1516. The new method has a certain significance to the study on the genetic law of cotton fiber color and the breeding of natural brown cotto n?