X-ray Spectrometric Method Research Articles

Analysis of aluminosilicate materials by X-ray fluorescence spectrometry

The high precision of X-ray fluorescence spectrometric analysis is often adversely affected by various interfering factors. In the analysis of aluminosilicate materials, mineralogical, particle-size and surface-finish effects can be eliminated by fusing the sample with a flux and inserting the specimen into the spectrometer as a polished cast disc.Inter-element effects can be overcome in several ways and in this work two methods are reported: a narrow range calibration, with slightly diluted specimens, for felspathic materials, and a multiple dilution method to cover a wide range of clays and refractories.Several examples of felspathic materials have been analysed very carefully by a combination of chemical and spectrochemical methods, and the results are compared with those from the X-ray spectrometric method described. The X-ray spectrometric method appears to offer advantages in cost and time, and the results obtained are satisfactory for control analysis.The multiple dilution method involves the use of standards that consist of pure compounds. This method was used to analyse a series of samples, including some commercially available standards. The results obtained indicate that the X-ray spectrometric method is considerably faster than the more commonly used combined methods, and that its accuracy is at least as good for normal control analysis.The multiple dilution method should be applicable to a wide range of materials, but it is dependent upon a sophisticated and carefully performed specimen preparation technique.

Combined Infrared and X-Ray Spectrometric Method for Determining Sulfonate and Sulfate Concentration of Detergent Range Alkylbenzene Sulfonate Solutions.

Combined Infrared and X-Ray Spectrometric Method for Determining Sulfonate and Sulfate Concentration of Detergent Range Alkylbenzene Sulfonate Solutions.

Copper Artifact Analysis with the X-Ray Spectrometer

AbstractThe X-ray spectrometer method as an archaeological tool is discussed with special reference to its limitations as a chemical analytical instrument. Qualitative results are presented for six North American copper samples, one European trade brass, and nine artifacts from the Great Lakes region. From this pilot study it is concluded that the most fruitful results in the problem of the determination of provenance of copper artifacts will be obtained from semi-quantitative optical spectographic analyses of carefully collected artifacts and raw materials. The largest inherent error in this problem is that of meaningful sampling techniques. The only recourse is to treat such chemical data statistically and determine the probabilities that given specimens came from the various possible sources.

The determination of niobium in pyrochlore soils

A method is described for the determination of niobium in pyrochlore soils, based upon the photometric measurement of the peroxy-complex.The samples are extracted with hydrofluoric acid, the niobium precipitated with tannin and the determination completed in sulphuric-phosphoric acid solution. This method of analysis has been examined using an isotope dilution technique and the final results compared with those obtained by polarographic and X-ray spectrometric methods.

Transformation characteristics of a lithium-magnesium alloy

The martensite-type transformation curves for a lithium-magnesium alloy were investigated in detail by X-ray spectrometer methods. Critical temperatures for formation and decomposition of the low-temperature phase were determined, and the influence of previous thermal and mechanical history investigated.

THE CRYSTAL STRUCTURE OF THIOUREA

Abstract Using the Laue photographic and X-ray spectrometric methods the crystal structure of thiourea was investigated. The unit of structure built upon the simple orthorhombic translation group Γ0, is of the dimensions a=5.47, b=7.64 and c=8.54 A., and contains four chemical molecules of CSN2H4. Thus the density is 1.408. The plausible space group being Vh16, a possible atomic arrangement, neglecting H atoms, was found to be as follows: (Remark: Graphics omitted.) with x=0.300, y=0.164 and z=0.144. The molecule has the symmetry of Cs, i.e. it has one plane of symmetry in it. In such a model, the distance. C–S is 1.81 Å., and that C–N is 1.39 Å. Discussion was also made upon its crystalline and molecular structures in comparison with those of urea.

The variation with temperature of the intensity of reflection of X-rays from quartz and its bearing on the crystal structure

Since the appearance of Sir William Bragg’s first work on the structure of martz (these ‘Proceedings,’ A, vol. 89, p. 595 (1914)) this mineral has been the subject of many investigations. It has lent itself very well to study by the older crystallographic methods, by which, from symmetry considerations, has been placed in the trapezohedral class of the trigonal system, i. e ., it exhibits trigonal symmetry about one ( c ) axis and digonal symmetry about ree others, lying symmetrically in a plane perpendicular to the first and intersecting in it. Two enantiomorphous forms were found to exist. Investigation by the X-ray spectrometer method enabled Bragg to give the dimensions of the unit triangular prismatic cell as a = 4·89 Å. U. and = 5·375 Å. U., whilst density considerations clearly indicated that three olecules were associated with such a unit cell. It was also shown that the three molecules were associated with the unit cell in such a way that planes of equal weight occurred at o , c /3, 2 c /3, c , etc., along the vertical c axis.