Emission spectrographic analyses

The authors wish to thank Mr. Edmund Huff of the Chemical Technology Division for performing the inductively couple plasma atomic emission spectrographic analyses. Work performed under the auspices of the Office of Basic Energy Sciences, Division of Chemical Sciences, U. S. Department of Energy under contract number W-31-109-ENG-38. 

Metal Analyses of Commercial Pigments. Quantitative emission spectrographic analyses were performed for 38 metals (Stewart Laboratories, Inc.). Detection limits for the 24 undetected metals are given in Table 3. 

The distribution of the elements are based on qualitative emission spectrographic analyses of the numbered segments. The Cs and Na distributions are based on quantitative analyses of each segment. Since Cs is concentrated in the leading band, the 137cs DF was dependent on the degree of column loading, i.e., for columns loaded to 50 capacity and washed with one column volume of water,... 

Transition metal dopants and impurities are probably incorporated substitutionally for Ti in BaTi03. Emission spectrographic analyses indicate that the distribution coefficients for Mn and Fe dopants are on the order of 1 to 2, i.e., the crystals are slightly enriched relative to the melt. Cr and Ni may have distribution coefficients slightly less than 1. For Co, the measured concentrations in the crystals display considerable scatter we estimate that the distribution coefficient is on the order of 4. Fe is the most prevalent transition metal impurity and is typically present at a concentration of 10-15 ppm by weight. Si, Al, Mg, and Cu are also typically present at 5-50 ppmw. Fe and Cr impurities have also been observed by EPR spectroscopy, although Cr could not be detected by emission spectroscopy, with a detection limit of 10 ppmw. 

Later laboratory demonstrations using actual solutions, however, showed that acceptably pure product could be precipitated from a 4 or 6 g Am/L solution, the equivalent of evaporating the solution to about 900 L. Emission spectrographic analyses showed the total impurities of the americium product from both the 4 and 6 g/L solutions to be about 1.5 wt %. 

Emission spectrographic analyses indicate the product to be of high purity and to contain the following impurities 02% Ba, 0.05% K, 0.005% Li, 0.005% Ca, and a faint trace (<0.01%) of Na.11 Attempts at preparing this compound by a chemical preparation using a tenfold or threefold excess of 30% H202 have failed to produce a similar product. 

Emission spectrographic analyses were performed by J. P. Fans of Argonne National Laboratory. 

Qualitative emission spectrographic analyses for macro-and trace element distribution have been undertaken routinely... 

Tables 2 and 3 present the chemical analyses data. Table 4 shows the free water, and Table 5 shows the pH for increment samples. Table 6 gives size distribution data. Tables 7 through 10 address radium, uranium, and thorium results, and Table II lists emission spectrographic analyses.

Particle size distribution is shown in Table 6. Three size distributions were used for uranium, thorium, radium and emission spectrographic analyses. These were the total coarse size (retained on 0.25-mm sieve), total medium size (passes 0.25-mm sieve, retained on 0.045-mm sieve), and fine size (passes 0.045-mm sieve). The coarse, medium, and fine fractions are also convenient summaries of the data. The cumulative percent distribution is a linear function of the logarithm of the sieve opening. 

Emission spectrographic analyses were performed on 13 core samples, on 90 3 m interval samples, and on 7 sized samples. This yielded 1780 individual analytical results for semiquantitative concentrations of 30 elements. These re suits are summarized in Table 11. 

Much the same problem exists in the materials analysis field today. The scientific literature contains numerous references to materials of 5-9 s and 6-9 s purity. Such statements are misleading and of questionable validity because the estimates are in many cases derived from resistivity measurements supplemented by emission spectrographic analyses (with a sensitivity of only 1-10 ppm for most elements). To establish that a sample of material contained less than 1 ppm total impurities would require analyses for all elements present by techniques with sensitivities and accuracies in the range 1-20 ppb. 

Specific absorption coefficient 650 Specific gravities solutions of acids, (T) 829 of selected reagents (T), 829 Spectral half bandwidth 663 Spectrofluorimetry 731 Spectrograph adjustment of, 771 commercial instruments, 761, 775, 776 Spectrographic analysis see Emission spectrographic analysis... 

Ultimately, all quantitative analytical methods rely upon standards, whose composition is determined by the classical techniques of wet chemical quantitative analysis. Obviously, the preferred techniques for analyzing art objects are nondestructive, such as x-ray fluorescence, neutron activation, electron microprobe (both dispersive and nondispersive techniques), and so forth. Emission spectrographic analysis is not suit-... 

Emission spectrographic analysis shows only silver and iron as major constituents. Of special interest is the fact that sodium is... 

The ampul is removed from the furnace and opened. Caution. Hydrogen selenide vapors are formed during the washing, and it is advisable that this operation also be performed in a hood. The crystals of cadmium chromium(III) selenide can be washed in water to remove the cadmium chloride. The crystals are black octahedra which vary in size up to about 3 mm. on an edge. The only impurities detected in these crystals by arc emission spectrographic analysis were Mg and Cu, and these are present only in amounts of less than 20 p.p.m. Anal. Calcd. for CdCr2 Se4 Cd, 21.1 Cr, 19.5 Se, 59.3. Found Cd, 20.8 Cr, 17.7 Se, 58.6. 

Several octahedral crystals were ground to powder and studied by the Guinier-Hagg technique (Cu radiation). All diffraction lines could be indexed on the basis of a cubic cell with a = 4.560 0.001 A., which is within experimental error of that reported previously for MnSi, 4.558 0.001 A.2 In view of the similarity of the cell constants of the ground crystals to those of previous preparations, significant replacement of manganese by copper is not indicated. This was checked on a few crystals by emission spectrographic analysis which indicated an upper limit of ca. 1% of copper. 

The amounts of 16 elements (see also Tab. 7-1) were determined with the above mentioned method of emission spectrographic analysis in a total of 170 samples of sedimented airborne particulates from three urban areas (Gera, Jena, and Greiz) in Thuringia (Germany) during one year of investigation. 

We wish to thank Mr. J. P. Fans of Argonne National Laboratory, who checked impurity levels in all materials reported in this series using emission spectrographic analysis techniques. This also confirmed the presence of the indicated metals. 

Materials. The UFe used in this work was a portion of a larger batch originally obtained from Oak Ridge National Laboratory. Almost two-thirds of the original batch had been distilled away in previous experimental work, presumably contributing to the purification of the UFe from low boiling impurities e.g., HF, CF4, F2). Emission-spectrographic analysis of the material indicated that the predominant impurities were P, at a concentration of <400 p.p.m., and As, B, Cs, Pd, Re, Sb, Sn, and Th, each present at concentrations of <100 p.p.m. Two determinations of the triple point of a sample of the UFe yielded values of 64.1 °C. and 64.2°C. The best literature value 19) for this is 64.05°C. 

Elements not increasing in concentration with ash content are generally those with (a) organic affinities (Ca, Mg, Sr, Ba) (b) sulfide affinities (Fe, Zn) (c) carbonate affinities (Ca, Mn, Mg) or (d) sulfate affinities (Ba, Sr, Ca). Sulfides, carbonates, and sulfates are generally epigenetic phases, that is, they precipitate in the cleats and fractures subsequent to coalification. Presence of epigenetic phases affects element concentration more than ash content. The concentrations of Zr and Nb would be expected to increase with ash content, because these elements are usually associated with the detrital compounds of coal. The reason that this behavior is not apparent in Table II may be the poor resolution of the technique (emission spectrographic analysis) used to obtain the data. 

Whereas quantitative emission spectrographic analysis jnelds accurate identification and elements present, an attempt at semi-quantitative interpretation frequently leads to erroneous conclusions. This unfortunate circumstance and its frequent abuse have brought the technique into disrepute, and, as,a result, its obvious and desirable features have been largely ignored. 

Emission spectrographic analysis indicated the product to be of high purity and confirmed the presence of only the metals Pt and Cs.8... 

The impurity contents of the fired samples were determined by emission spectrographic analysis, and detailed data are presented in Reference 18. In summary, forthe mullite batches, impurity levels were less than 1000 ppm, with W,Zr and Naas the major impurities. Forthe mullite-Zr02 batches, total impurity contents were 1000 to 1500 ppm, with Fe, W, Ni and Ca as the maj or impurities. It is believed that most of the impurities were introduced during the powder processing. The SiC whiskers contained -7000 ppm impurities, with Ca, Al, Mg, Fe and Cr as the major contributors. 

In 1912 Shibata moved to Paris to study under Georges Urbain (1872-1938). He intended to study the rare earth elements, but Urbain advised him not to do so because such study required tedious fractional crystallization, which was not suitable for a foreign chemist with only limited time to spend. Instead, Urbain suggested that Shibata carry out absorption spectrographic studies of cobalt complexes. Fortunately, Shibata was able to use the newly obtained medium-sized quartz spectrograph of Adam Hilger, type E2, and he carried out absorption measurements of cobalt-ammine complexes (5). In Urbains s laboratory Shibata also learned from Jacques Bardet the technique of emission spectrographic analysis, which Shibata later used to analyze the rare earth minerals found in Japan. 

Emission spectrography. The polymer is ashed as above and the ash blended with carbon containing 0.1% palladium prior to emission spectrographic analysis for sodium. Calibration is achieved against known blends of sodium carbonate in magnesium sulphate. 

Thermogravimetric analysis (25-100°) shows a <0.05% weight loss, indicating that Tl4(C03)[Pt(CN)4] is anhydrous. Emission spectrographic analysis indicates the product to be of high purity it contains the metals Tl and Pt and impurities as follows faint traces of Ca and Li (<0.001%). Iodine-thiosulfate titration studies are negative, indicating no partial oxidation of Pt therefore, Pt is present as Pt °. 

Analysis of refined germanium products is done in a wide variety of ways, including several methods that have become ASTM standards (47). Electronic-grade Ge02 is analyzed using an emission spectrograph to determine its spectrographic purity. Its volatile content is measured in accord with ASTM F5 and its bulk density with F6. Other ASTM standards cover the preparation of a metal biHet from a sample of the oxide (F27), and the determination of the conductivity type (F42) and resistivity (F43) of the biHet. 

Ultrapure (triple distilled) mercury is commonly tested by evaporation or spectrographic analysis. In the former, a composite sample is evaporated and the residue weighed. In spectrographic analysis, a sample is dissolved and evaporated, the residue mixed with graphite [7782-42-5] and the emission spectmm determined with a spectrograph. 

Rubidium metal is commeicially available in essentially two grades, 99 + % and 99.9 + %. The main impurities ate other alkali metals. Rubidium compounds are available in a variety of grades from 99% to 99.99 + %. Manufacturers and suppliers of mbidium metal and mbidium compounds usually supply a complete certificate of analysis upon request. Analyses of metal impurities in mbidium compounds are determined by atomic absorption or inductive coupled plasma spectroscopy (icp). Other metallic impurities, such as sodium and potassium, are determined by atomic absorption or emission spectrograph. For analysis, mbidium metal is converted to a compound such as mbidium chloride. 

It is obvious that a record of the kind in Figure 7-1 can yield valuable information about an unknown mineral in the minimum time at little cost. The x-ray emission spectrograph may well become the most valuable single tool for the qualitative analysis of minerals. Its advantages are obvious enough to make further discussion supererogatory. 

In 1951Castaing8 published results to show that an electron microscope could be converted into a useful x-ray emission spectrograph for point-to-point exploration on a micron scale. The conversion consisted mainly in adding a second electrostatic lens to obtain a narrower electron beam for the excitation of an x-ray spectrum, and adding an external spectrometer for analysis of the spectrum and measurement of analytical-line intensity. Outstanding features of the technique were the small size of sample (1 g cube, or thereabouts) and the absence of pronounced absorption and enhancement effects, which, of course, is characteristic of electron excitation (7.10). Castaing8 gives remarkable quantitative results for copper alloys the results in parentheses are the quotients... 

The apparatus as modified for x-ray emission spectrograph is also shown in Figure 11-1. The proportional counter may be used alone (pulse-height analysis Section 2.13) or a curved-crystal spectrometer can be employed to achieve better resolution. Analytical results were comparable to those quoted above, but localization of the area analyzed was considerably less sharp than the micron-diameter spot achieved in differential absorptiometry. 

---