不同炮制时间茜草炭的色度值与特征图谱的相关性研究

Correlation Between Chromaticity Value and Characteristic Map of Different Processing Time of Carbonized Rubiae radix et Rhizoma

目的考察茜草炭炮制过程中饮片色度值与超高效液相色谱法(UPLC)特征图谱的相关性。方法采用UPLC建立茜草及茜草炭的特征图谱,并采用分光测色仪测定其色度值:明暗度值(L*)、红绿色值(a*)、黄蓝色值(b*),对茜草炭炮制过程中饮片色度值与特征图谱进行相关性分析。结果随着炮制时间的延长,茜草炭较茜草饮片特征图谱的相似度逐渐降低;异茜草素、6-羟基甲基异茜草素单位峰面积先增大后减小,其余共有峰单位峰面积均呈减小趋势;L*、a*、b*值整体上逐渐减小,而△E*逐渐增大。L*、a*、b*值分别与羟基茜草素、6-羟基甲基异茜草素、茜草素呈极显著正相关。主成分分析共提取2个主成分,累积方差贡献率为88.292%。聚类分析结果显示,炮制0~6 min的样品聚为一类,炮制8~34 min的样品聚为二类。正交偏最小二乘法判别分析结果显示,6-羟基甲基异茜草素、异茜草素、a*、b*是茜草炭饮片炮制过程中发生质量变化的主要指标。结论不同炮制时间茜草炭饮片的色度值与UPLC特征图谱密切相关,可为茜草炭饮片炮制的在线监控和质量评价提供较全面的判断依据。

OBJECTIVE To investigate the correlation between the chromaticity value and UPLC characteristic map of carbonized Rubiae Radix et Rhizoma radix of rhizoma(cRRR)pieces of different processing time.METHODS UPLC method was used to establish the characteristic map of madder and cRRR,and spectrophotometric colorimeter was used to determine the chromaticity value(L*,a*,b*)of the samples,and the correlation between the chromaticity value and the characteristic map of Rubiae Radix et Rhizoma pieces during processing was analyzed.RESULTS With the prolonging of processing time,the similarity of Rubiae Radix et Rhizoma and madder pieces decreased gradually.The unit peak areas of isomadder and 6-hydroxymethylmadder first increased and then decreased,while the other common peaks showed a decreasing trend.The values of L*,a*and b*decrease gradually,while△E*increases gradually.The values of L*,a*and b*were significantly positively correlated with hydroxyl madder,6-hydroxylmethylmadder and madder,respectively.Two principal components were extracted by principal component analysis,and the cumulative variance contribution rate was 88.292%.The results of cluster analysis showed that the samples processed for 0-6 min were clustered into one class,and those processed for 8-34 min were clustered into two classes.The results of orthogonal partial least squares discriminant analysis showed that 6-hydroxymethylmadder,isomadder,a*and b*were the main indexes of quality change of Rubiae Radix et Rhizoma pieces during processing.CONCLUSION The chromaticity value of different processing time of Rubiae Radix et Rhizoma pieces is closely related to the UPLC characteristic map,which could provide a comprehensive basis for online monitoring and quality evaluation of Rubiae Radix et Rhizoma pieces.