Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer a...Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.展开更多
The sonolytic degradation of 2-chlorobiphenyl was investigated. Mass spectroscopy was used to detect the products of sonolytic degradation of 2-chlorobiphenyl. The results show that the products of sonolytic degradati...The sonolytic degradation of 2-chlorobiphenyl was investigated. Mass spectroscopy was used to detect the products of sonolytic degradation of 2-chlorobiphenyl. The results show that the products of sonolytic degradation, such as biphenyl, ethyl benzene, diethylbiphenyl, dibutylbiphenyl, phenol, propylphenol and di-tert-butyl phenol are produced by thermolysis and hydroxyl free radical reactions, in which biphenyl counts for almost 40%（mole fraction） of the mother compound and others are at trace level. Rapid accumulation of chloride ion shows quick dechlorination, and 78% organic chlorine is converted into chloride ion. Free radical scavengers, bicarbonate and carbonate, decrease the reaction rate of sonolytic degradation of 2-chlorobiphenyl significantly, and the pseudo 1st order rate constant of sonolytic degradation of 2-chlorobiphenyl decreases linearly with the natural logarithm of the concentration of the added free radical scavenger, showing that the pyrolysis and hydroxyl free radical reaction are the two major pathways for the sonolytic degradation of 2-chlorobiphenyl, in which the hydroxyl radical concentration is estimated to be 1×10-10 （mol/L.）展开更多
文摘Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.
文摘The sonolytic degradation of 2-chlorobiphenyl was investigated. Mass spectroscopy was used to detect the products of sonolytic degradation of 2-chlorobiphenyl. The results show that the products of sonolytic degradation, such as biphenyl, ethyl benzene, diethylbiphenyl, dibutylbiphenyl, phenol, propylphenol and di-tert-butyl phenol are produced by thermolysis and hydroxyl free radical reactions, in which biphenyl counts for almost 40%（mole fraction） of the mother compound and others are at trace level. Rapid accumulation of chloride ion shows quick dechlorination, and 78% organic chlorine is converted into chloride ion. Free radical scavengers, bicarbonate and carbonate, decrease the reaction rate of sonolytic degradation of 2-chlorobiphenyl significantly, and the pseudo 1st order rate constant of sonolytic degradation of 2-chlorobiphenyl decreases linearly with the natural logarithm of the concentration of the added free radical scavenger, showing that the pyrolysis and hydroxyl free radical reaction are the two major pathways for the sonolytic degradation of 2-chlorobiphenyl, in which the hydroxyl radical concentration is estimated to be 1×10-10 （mol/L.）
