ABSTRACT
Objective:To measure the color values of Gentianae Radix et Rhizoma and the contents of gentiopicroside,the appearance index value of the representative color was correlated with the intrinsic index value representing the quality,in order to explore the correlation between the contents of active ingredients and the color values,and provide basis for the quality evaluation of Gentianae Radix et Rhizoma. Method:The color difference values of Gentianae Radix et Rhizoma powder was measured by colorimeter.The content determination method of gentiopicroside in the 2015 edition of China Pharmacopoeia was adopted. The content of gentiopicroside was determined by HPLC,and the correlation and regression analysis was carried out by SPSS 21.0 software. Result:There was a significantly positive correlation between the contents of gentiopicroside and L* (representing colorshade)and E* ab(representing total color difference)(Pa* (representing color red-green direction) and b* (representing color yellow-blue direction) had a significantly negative correlation (PConclusion:The color value of Gentianae Radix et Rhizoma has a certain correlation with the content of gentiopicroside,and yellowish Gentianae Radix et Rhizoma contain more active ingredients, with a better quality.The contents of gentiopicroside active ingredients in Gentianae Radix et Rhizoma can be quickly predicted by determining the color difference values,which can provide a new idea for quality evaluation of this herb.
ABSTRACT
An analytical method was developed for determination of low-level uranium isotopes in vegetation samples. Dry ashing method was employed to decompose organic matters of vegetation. The sample ash was further digested using multiple acids. Uranium in the prepared sample solution was separated and purified by an extraction chromatography using UTEVA resin. The chemical recovery of uranium in the separation procedure was more than 94% , and more than 99% of Na, K, Ca and other matrix elements and interfering elements were removed. Three natural uranium isotopes were finally measured with high sensitivity ICP-MS/MS. The detection limits of the method for 238U, 235U, 234U were 3. 05, 0. 34 and 0. 04 pg/g, respectively. The detection limits for 238U and 235U were 10 times better than the reported values. Analysis result of U in GBW-10046 standard reference material was in good agreement with reference value, indicating that this method was reliable. The method was successfully applied to determination of uranium isotopes in the vegetation samples collected in Xi′an region, and it was found that the uranium concentrations and isotopic ratios in these vegetation samples fall well into natural level, and there was no significant artificial uranium contamination. This was the first survey of the three natural uranium isotopes in vegetation samples in this region.