Diffraction powder, analysis

Yamamoto H, Matsuyama T, Wada M. 2002. Shape distinction of particulate materials by laser diffraction powder analysis. Powder Technol. 122 205-211. 

Solid compounds, solid solutions, and solid mixtures can be differentiated through X-ray diffraction powder analysis and DSC, or other thermoanalytical techniques as mentioned in Sections 2,4.2 and 2.5.2. 

X-Ray Diffraction Powder Analysis Synthesis Stability Metabolism Methods of Analysis... 

X-Ray Diffraction Powder Analysis Rajeswaran and Kirk (1) have reported... 

The Rietveld Fit of the Global Diffraction Pattern. The philosophy of the Rietveld method is to obtain the information relative to the crystalline phases by fitting the whole diffraction powder pattern with constraints imposed by crystallographic symmetry and cell composition. Differently from the non-structural least squared fitting methods, the Rietveld analysis uses the structural information and constraints to evaluate the diffraction pattern of the different phases constituting the diffraction experimental data. 

US patent 6,723,728, Polymorphic and other crystalline forms cis-FTC [106], The present invention relates to polymorphic and other crystalline forms of (—)-and ( )-cA-(4-amino-5-fluoro-l-(2-(hydroxymethyl)-l,3-oxathiolan-5-yl)-2(lH)-pyrimidinone, or FTC) [106]. Solid phases of (—)-cz>FTC that were designated as amorphous (—)-FTC, and Forms II and III were found to be distinguishable from Form I by X-ray powder diffraction, thermal analysis properties, and their methods of manufacture. A hydrated crystalline form of ( )-cA-FTC and a dehydrated form of the hydrate, were also disclosed, and can similarly be distinguished from other forms of FTC by X-ray powder diffraction, thermal properties, and their methods of manufacture. These FTC forms can be used in the manufacture of other forms of FTC, or as active ingredients in pharmaceutical compositions. Particularly preferred uses of these forms are in the treatment of HIV or hepatitis B. 

Practical aspects of powder diffraction data analysis, Stud. Surf Sd. Catal., vol. 85, Elsevier, Amsterdam, pp. 391 28. 

It is possible that the future may also see the use of digital calculators in qualitative spectrometric analyses. Various types of punched cards have been used as a method of recording spectral data on pure compounds. The purpose of these files is to facilitate the identification of spectral data on unknown substances. Their use in infrared analysis has been covered by Mecke and Schmid (M6), Keuntzel (K3), and Baker, Wright, and Opler (B2). The last named authors describe a file of 3150 spectra which was expected eventually to be expanded to include up to 10,000 spectra. Zemany (Zl) discussed the use of edge-notched cards in cataloging mass spectra and Matthews (M4) describes a similar application in connection with X-ray diffraction powder data. These two applications made use of only hand-sorting methods the files of Baker et al. were intended to be processed by machine. 

Two types of X-ray studies are commonplace X-ray powder analysis and crystal structure determination. Even in powders, the regular arrangement of atoms within the solid leads to characteristic diffraction patterns. X-ray powder patterns may therefore be used to characterize solids in much the same way that a UV or IR spectrum will give useful information but not necessarily a definitive structure. 

IR and Raman spectra of ofloxacin and levofloxacin were measured and evaluated [06SA(A)159]. Saccharin salt of ofloxacin was prepared and characterized by FTIR, X-ray powder diffraction, thermal analysis, and and 13C NMR spectroscopy in solution and in solid state (09JPS3788). Nondestructive discrimination between levofloxacin and ofloxacin containing tablets was achieved by using diffusion reflectance NIR spectroscopy (08PHA628). 

In Mode I (feeding time 1 min), the results are similar to those obtained in the repeated verifying experiments mentioned in the previous section. The TEM photo of the product shows particle-clumping and the results of X-ray diffraction (XRD) analysis indicate that the product consists mainly of copper powder with a little Cu20. The X-ray spectrum of the product obtained in this feeding mode is shown in Fig. 14.3, which indicates the major part being Cu, with little Cu20 and no CuO. 

Early investigations of the PrNiSb compound showed that it had the AlB2-type structure with a = 0.4376, c = 0.4053 (Pecharsky et al., 1983a X-ray powder analysis). For experimental procedure, see ScNiSb. At variance with these data, Hartjes and Jeitschko (1995) suggested a ZrBeSi type structure, a = 0.4375, c = 0.8123 from X-ray powder diffraction. For experimental details, see LaNiSb. 

X-Ray Diffraction Data. The X-ray diffraction powder patterns of the cancrinites, referred to in the synthesis section, have been indexed in accordance with the space group P63 as found by Jarchow (16). Table II reports the cell parameters of the three synthetic cancrinite samples and of a natural sample (16) for comparison. Chemical Analysis. Data for the three cancrinite samples on anhydrous basis are shown in Table III. Values of water content are reported in the next section. 

All available methods of diffraction, microscopy, and spectroscopy are used for structure elucidation in present-day materials chemistry.1,2 For detailed structure determination, even powders suffice for the most part because of the advances in diffraction profile analysis. These advances in structural tools enable more meaningful correlations of structure with properties and phenomena. Catalysis is becoming more of a science partly because of our ability to unravel the structures and surfaces of catalysts. Phase transitions of all varieties5 are being investigated more and more by chemists. 

The amount of adsorbed metal was determined by the weight difference of the pre-and post-sorption sorbent. The structural and morphological change of kaolinite granules during sorption tests was investigated by the powdered X-ray diffraction (XRD) analysis (Philips, X pert MPD) and scanning electron microscopy (SEM) (JEOL, JXA 8600). 

X-Ray diffraction (XRD) of the green material from side B of the halberd produced the powder pattern characteristic of malachite as well as another pattern that was attributed to some aluminum oxide or hydroxide. The exact form of the aluminum material could not be determined conclusively from the data available. XRD analysis of mixtures is difficult and involves more speculation than that of a pure material, particularly in ancient alloys (JO). Although the diffraction powder pattern of the green fiber pseudomorphs from side A was not as clear as that of the green nodule from side B, all of the lines apparent in the pattern could be correlated with those of the green nodule. The two must contain the same material, that is, malachite and some aluminum oxide or hydroxide. 

---