A new method of the quantitative phase analysis of the sample containing an amorphous phase or a standardless phase by X-ray diffraction is proposed in the paper. The addtion of a reference phase or some analytical ph...A new method of the quantitative phase analysis of the sample containing an amorphous phase or a standardless phase by X-ray diffraction is proposed in the paper. The addtion of a reference phase or some analytical phase to the analyzed sample is not required in this method and the experimental results are satisfactory.展开更多
A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtai...A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtained. For a multicomponent system in which (n-2) pure phases are added into an n-phase compnent sample and theweight fractions of all n phases can be determined by the method. The test results of confirmation agree well with the theory.展开更多
Calcium silicate slag is the residue of process of pre-desilication alkali lime sintering applied in the high-alumina fly ash to extract the alumina.The quantitative phase analysis(QPA) of the calcium silicate slag ha...Calcium silicate slag is the residue of process of pre-desilication alkali lime sintering applied in the high-alumina fly ash to extract the alumina.The quantitative phase analysis(QPA) of the calcium silicate slag has been performed by the Rietveld method based on the powder X-ray diffraction(XRD) with the aid of noncommercial software GSAS-EXPGUI.A known weight of crystalline internal standard(10% CaF_2) was added to the calcium silicate slag to calculate the fraction of amorphous phase and other crystalline phases on an absolute basis.Besides,the calcium silicate slag was characterized by X-ray fluorescence(XRF) and thermo gravimetric(TG) differential scanning calorimetry(DSC) to test the QPA results and investigate its other characters.Finally,the results show that the amorphous fraction is 17.5%(hereinafter,the percentages refer to the mass fraction),and the major crystalline phases detected in the calcium silicate slag consist of 23.5% Beta-Ca_2 SiO_4,10.0% bredigite,10.3% Ca_3Al_2O_6(C_3A) and 21.6% CaCO_3.展开更多
A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample ...A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.展开更多
Tibolone, a synthetic steroid, is used in the treatment of natural or surgical menopause disturbs resultant of estrogenic deficiency. Isotibolone (Δ4-tibolone) is one of the three active metabolic degradation product...Tibolone, a synthetic steroid, is used in the treatment of natural or surgical menopause disturbs resultant of estrogenic deficiency. Isotibolone (Δ4-tibolone) is one of the three active metabolic degradation products of tibolone that displays progestagenic effects on carcinoma cell growth and gene regulation. Isotibolone can be present in raw material of tibolone due to some inadequate synthesis or storage. Its presence is necessary to be identified and quantified in active pharmaceutical ingredients (API), before its use in the manufacturing of medicines. After a recent study on the crystal structure determination of isotibolone, quantitative phase analyses of both tibolone and isotibolone in raw materials and tablets became possible to be conducted. X-ray powder diffraction is one recommended tool for this purpose, but it can be highly frustrating due to the extreme peak overlap when conventional laboratory equipments are used. In this work we show that the use of Brazilian Synchrotron Light Source X-ray powder diffraction data and the Rietveld method can be successfully applied to identify and quantify the isotibolone in two samples of tibolone raw materials.展开更多
文摘A new method of the quantitative phase analysis of the sample containing an amorphous phase or a standardless phase by X-ray diffraction is proposed in the paper. The addtion of a reference phase or some analytical phase to the analyzed sample is not required in this method and the experimental results are satisfactory.
文摘A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtained. For a multicomponent system in which (n-2) pure phases are added into an n-phase compnent sample and theweight fractions of all n phases can be determined by the method. The test results of confirmation agree well with the theory.
基金the National Natural Science Foundation of China(Nos.51302012 and 51274042)the China Postdoctoral Science Foundation Funded Project(No.2016T90034)the Inner Mongolia Science and Technology Major Projects 2013
文摘Calcium silicate slag is the residue of process of pre-desilication alkali lime sintering applied in the high-alumina fly ash to extract the alumina.The quantitative phase analysis(QPA) of the calcium silicate slag has been performed by the Rietveld method based on the powder X-ray diffraction(XRD) with the aid of noncommercial software GSAS-EXPGUI.A known weight of crystalline internal standard(10% CaF_2) was added to the calcium silicate slag to calculate the fraction of amorphous phase and other crystalline phases on an absolute basis.Besides,the calcium silicate slag was characterized by X-ray fluorescence(XRF) and thermo gravimetric(TG) differential scanning calorimetry(DSC) to test the QPA results and investigate its other characters.Finally,the results show that the amorphous fraction is 17.5%(hereinafter,the percentages refer to the mass fraction),and the major crystalline phases detected in the calcium silicate slag consist of 23.5% Beta-Ca_2 SiO_4,10.0% bredigite,10.3% Ca_3Al_2O_6(C_3A) and 21.6% CaCO_3.
文摘A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.
基金the financial support of FAPESP(proc.nos.2008/10537-3,2010/06849-0)CAPES and CNPq(proc.nos.476335/2008-6,309811/2009-0,306293/2009-9 and 477296/2011-4)and the LNLS(Brazilian Synchrotron Light Laboratory)for beam time.
文摘Tibolone, a synthetic steroid, is used in the treatment of natural or surgical menopause disturbs resultant of estrogenic deficiency. Isotibolone (Δ4-tibolone) is one of the three active metabolic degradation products of tibolone that displays progestagenic effects on carcinoma cell growth and gene regulation. Isotibolone can be present in raw material of tibolone due to some inadequate synthesis or storage. Its presence is necessary to be identified and quantified in active pharmaceutical ingredients (API), before its use in the manufacturing of medicines. After a recent study on the crystal structure determination of isotibolone, quantitative phase analyses of both tibolone and isotibolone in raw materials and tablets became possible to be conducted. X-ray powder diffraction is one recommended tool for this purpose, but it can be highly frustrating due to the extreme peak overlap when conventional laboratory equipments are used. In this work we show that the use of Brazilian Synchrotron Light Source X-ray powder diffraction data and the Rietveld method can be successfully applied to identify and quantify the isotibolone in two samples of tibolone raw materials.