Ultraviolet-visible Spectrophotometry And Near Infrared Spectrum Technology In The Application Of Licorice Quality Quick Analysis Research

In view of the situation that licorice from different sources exists significant differences in the active ingredient contents, Licorice quality is uneven. Now the commonly used detection mean for licorice quanlity is HPLC, but HPLC has several shortages such as time-consuming, high analysis cost and low applicability. So, a simple and rapid quality analysis method to detect the active ingredient in licorice is necessary. This paper starts form the view of establishing qualitative and quantitative mathematical models, with the use of mathematical statistics method and statistic analysis software, in order to develop a simple and rapid quanlity analysis method for licorice with the application of uv-vis spectrophotometry, the near infrared spectroscopy and chromaticity analysis method respective. The main research results are as follows:(1) On the basis of the existing determination method for licorice active ingredients, this paper has established a more simple and rapid determination method for total Licorice saponins and flavonoids with the use of uv-vis spectrophotometry; has established a method to determinate glycyrrhizin, liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin simultaneously with the use of HPLC.(2) There exsits a very significant positive correlation between glycyrrhizin and total saponins, there also exsits a very significant positive correlation between liquiritin, liquiritigenin, isoliquiritin, isoliquiritigenin and total flavonoids. This paper has established discriminant models, through which we can discriminant the contents range of glycyrrhizin and liquiritin only if we get the contents of total saponins and total flavonoids, the discriminant accuracy of glycyrrhizin discriminant model is91.3%, and the discriminant accuracy of liquiritin discriminant model is90.0%; this paper has established linear regression models, through which we can estimiate the contents of glycyrrhizin and liquiritin only if we get the contents of total saponins and total flavonoids, the estimiate accuracy of glycyrrhizin discriminant model is68.6%and the estimiate accuracy of liquiritin discriminant model is75.3%.(3) This paper has established calibration models between glycyrrhizin content and NIR spectrum of wild and cultivated licorice, the R of the wild and cultivated calibration models are both above0.999, the predicting accuracy are91.4%and95.7%respective; has eatabliseh calibration models between liquirtin content and NIR spectrum of wild and cultivated licorice, the R of the wild and cultivated calibration models are0.996and0.998respective, the the predicting accuracy are86.2%and93.2%respective; has eatabliseh calibration models between isoliquirtin content and NIR spectrum of wild and cultivated licorice, the R of the wild and cultivated calibration models are both above0.999, the the predicting accuracy are89.4%and89.0%respective.(4) There don’t exist significant differences between licorice with different surface colour in total saponins, total flavonoids, glycyrrhizin, liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin contents, but licorice with different Section color has very significant differences in total saponins contents and has significant differences in glycyrrhizin, liquiritin, liquiritigenin and liquiritin, contents. The chromaticity analysis results shows that the Lightness value L*of the licorice powder with shin off has significant negative correlation with total saponins and isoliquiritigenin content, and the yellow value b*has significant positive correlation with glycyrrhizin content, and the yellow index Y1has significant positive correlation with total saponins and glycyrrhizin content.(5) NIR is the most suitable method in the Licorice quality fast detection from the speediness, simplification, economy and accuracy aspects. This paper has revalidated the glycyrrhizin, liquiritin and isoliquiritin NIR models. The results show that the glycyrrhizin and liquiritin NIR models are stable, but the isoliquirtin NIR model is unstable.