Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in t...Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in three factors, 5% phenol volume, H2SO4 volume, and temperature of water bath, we adopted the L9（3）3 orthogonal array design to gain the optimal colorimetric method. 3.0 ml of polysaccharide solution, 1.0 ml, 5% phenol and 7.0 ml H2SO4 were mixed with constant stirring in a glass vessel, and then kept in a water bath at 40 ℃. After cooling to room temperature for 20 min, the absorbance values were recorded by the UV-2501 PC spectrometer at the wavelength range of 485 nm. The polysaccharide content in Curcuma wenyujin were 3.21%, 3.23%, 3.20%, 3.18~/0, 3.22% and 2.38%, respectively. All results showed that this method was adequate, valid and applicable, may be applied to the determination of other bacterial polysaccharide as well.展开更多
The quantification of transparent exopolymer particles(TEP) by colorimetric method is of large error and low repeatability,one major reason of which is related to the absence of clear definition and evaluation for par...The quantification of transparent exopolymer particles(TEP) by colorimetric method is of large error and low repeatability,one major reason of which is related to the absence of clear definition and evaluation for part steps of the original method.It is obscure that the 80% sulfuric acid solution,acted as the extraction solution in the determination of TEP,is prepared based on a volume ratio or mass ratio.Furthermore,the change of solubility of recently available Gum Xanthan(GX) from the market means that the original protocol is no longer applicable,and the grinding of GX stock solution with a tissue grinder is replaced by shaking with a rotating shaker in the study to prevent the excessive dissolution of GX.We found that different preparation techniques could result in the varied concentrations of 80% H_(2)SO_(4).The duration of shaking during the preparation of standard solution significantly affected the slope of the calibration curve,which caused different correction results of TEP.The impacts of different extraction solution concentrations and shaking time of GX solution on the quantification of TEP were investigated based on the field sampling and laboratory analysis.The extraction capacities of H_(2)SO_(4) with different concentrations for Alcian Blue were distinct,but had limited effect on the final measuring result of TEP.The change of the standard curve slope came along with the variation of shaking time,which markedly altered the detection limit and calibration result,and the extended shaking time was in favor of the determination of low-concentration TEP.It was suggested that the extraction solution concentration,shaking time and filtration volume of standard solution are required to be well controlled and selected to obtain more accurate results for TEP with different concentrations.展开更多
[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selec...[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selected to recrystallize Jinggangmycin （content 62% ）. Phenol-sulfuric acid colofirnetric method was adopted to determine its content, and the effects of different determination conditions on the content results were also studied. E Result~ The purity of the samples after re-eryatallization was increased to 97.7%. The optimal conditions for phenol-sulfuric acid colorimetric method to determine the content of Jinggan^nyein were as follows： anhydrous glucose as control sample, 5% phenol, 1.0 ml phenol solution, 5.0 nfl sulfuric acid, stilly placed for20 min after reaction, 490 nm as detec- tion wavelength; the correlation coefficient of glucose standard curve （ R2 ） was 0. 993 9; the average recovery of standard addition was 99.72%, RSD was 0. 362 8%. ~ Conclusion] Re-cryatallization is a good way to refine Jinggan^nycin. Phenol-sulfuric acid colorimetric method can be used to determine the content of Jinggangmycin with simple operation, high accuracy and strong reliability, which can be widely applied in industrial production.展开更多
文摘Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in three factors, 5% phenol volume, H2SO4 volume, and temperature of water bath, we adopted the L9（3）3 orthogonal array design to gain the optimal colorimetric method. 3.0 ml of polysaccharide solution, 1.0 ml, 5% phenol and 7.0 ml H2SO4 were mixed with constant stirring in a glass vessel, and then kept in a water bath at 40 ℃. After cooling to room temperature for 20 min, the absorbance values were recorded by the UV-2501 PC spectrometer at the wavelength range of 485 nm. The polysaccharide content in Curcuma wenyujin were 3.21%, 3.23%, 3.20%, 3.18~/0, 3.22% and 2.38%, respectively. All results showed that this method was adequate, valid and applicable, may be applied to the determination of other bacterial polysaccharide as well.
基金The National Key Research and Development Project of China under contract No.2019YFC1407805the National Natural Science Foundation of China under contract Nos 41876134, 41676112 and 41276124+1 种基金the Tianjin 131 Innovation Team Program under contract No.20180314the Changjiang Scholar Program of Chinese Ministry of Education under contract No.T2014253。
文摘The quantification of transparent exopolymer particles(TEP) by colorimetric method is of large error and low repeatability,one major reason of which is related to the absence of clear definition and evaluation for part steps of the original method.It is obscure that the 80% sulfuric acid solution,acted as the extraction solution in the determination of TEP,is prepared based on a volume ratio or mass ratio.Furthermore,the change of solubility of recently available Gum Xanthan(GX) from the market means that the original protocol is no longer applicable,and the grinding of GX stock solution with a tissue grinder is replaced by shaking with a rotating shaker in the study to prevent the excessive dissolution of GX.We found that different preparation techniques could result in the varied concentrations of 80% H_(2)SO_(4).The duration of shaking during the preparation of standard solution significantly affected the slope of the calibration curve,which caused different correction results of TEP.The impacts of different extraction solution concentrations and shaking time of GX solution on the quantification of TEP were investigated based on the field sampling and laboratory analysis.The extraction capacities of H_(2)SO_(4) with different concentrations for Alcian Blue were distinct,but had limited effect on the final measuring result of TEP.The change of the standard curve slope came along with the variation of shaking time,which markedly altered the detection limit and calibration result,and the extended shaking time was in favor of the determination of low-concentration TEP.It was suggested that the extraction solution concentration,shaking time and filtration volume of standard solution are required to be well controlled and selected to obtain more accurate results for TEP with different concentrations.
文摘[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selected to recrystallize Jinggangmycin （content 62% ）. Phenol-sulfuric acid colofirnetric method was adopted to determine its content, and the effects of different determination conditions on the content results were also studied. E Result~ The purity of the samples after re-eryatallization was increased to 97.7%. The optimal conditions for phenol-sulfuric acid colorimetric method to determine the content of Jinggan^nyein were as follows： anhydrous glucose as control sample, 5% phenol, 1.0 ml phenol solution, 5.0 nfl sulfuric acid, stilly placed for20 min after reaction, 490 nm as detec- tion wavelength; the correlation coefficient of glucose standard curve （ R2 ） was 0. 993 9; the average recovery of standard addition was 99.72%, RSD was 0. 362 8%. ~ Conclusion] Re-cryatallization is a good way to refine Jinggan^nycin. Phenol-sulfuric acid colorimetric method can be used to determine the content of Jinggangmycin with simple operation, high accuracy and strong reliability, which can be widely applied in industrial production.
