Spark source mass standards

Table 8.60 shows the main features of GD-MS. Whereas d.c.-GD-MS is commercial, r.f.-GD-MS lacks commercial instruments, which limits spreading. Glow discharge is much more reliable than spark-source mass spectrometry. GD-MS is particularly valuable for studies of alloys and semiconductors [371], Detection limits at the ppb level have been reported for GD-MS [372], as compared to typical values of 10 ppm for GD-AES. The quantitative performance of GD-MS is uncertain. It appears that 5 % quantitative results are possible, assuming suitable standards are available for direct comparison of ion currents [373], Sources of error that may contribute to quantitative uncertainty include sample inhomogeneity, spectral interferences, matrix differences and changes in discharge conditions. 

Precision expressed as 95% confidence intervals Spark source mass spectrometry, internal standard method From [735]... 

Because of the very important role of impurities in determining semiconductor properties, it is desirable to know their concentrations, at least of the electrically active ones. Of course, the techniques we have discussed in this chapter never make a positive identification of a particular impurity without confirmation by one of the established analytical techniques, such as spark-source mass spectroscopy (SSMS) or secondary-ion mass spectroscopy (SIMS). Once such confirmation is established, however, then a particular technique can be considered as somewhat of a secondary standard for analysis of the impurity that has been confirmed. It must be remembered here that an analytical method such as SSMS will see the total amount of the impurity in question, no matter what the form in the lattice, whereas an electrical technique will see only that fraction that is electrically active. 

A Xany insights into early civilizations have been provided by the study of ceramics. Various physical and chemical methods are considered standard techniques for modem archaeology (I, 2). The macroanalysis, microanalysis, and trace chemical analysis of artifacts have added greatly to the understanding of prehistoric civilizations (3-6). The chemical techniques used for ceramic analysis have included spark source mass spectrometry (7) ... 

While high sensitivity has been obtained in the examination of pure materials, a far more rigorous test of the activation method is found in its application to materials of a more complex matrix. Emission and X-ray spectrometry and direct spark source mass spectrometry are all restricted by the lack of suitable standards when applied to materials of complex composition. Provided that precautions are taken to avoid self-shielding errors radioactivation is largely independent of the nature of the matrix material. It is this advantage which has enabled activation analysis to prove such an invaluable tool in geochemistry. 

Standard Mean Ocean Water — the standard used in oxygen and hydrogen stable isotopic measurements Spark Source Mass Spectrometry syn-COLlisional Granite... 

Radermacher, L., Breske, H. E. Improvement of analysis in spark-source mass spectrometry without standards by complete use of photoplate information. In Advances in mass spectrometry, 7A. Daly, N. R. (ed.). London Heyden 1978, pp. 545-548... 

Gauneau, M., Rupert, A., Minier, M., Regreny, O., CoquiUe, R. (1960) Use of implanted samples as standards in spark-source mass spectrometry with application to the analysis of III-V semiconductors. Analytica ChimicaActa, 135,193—204. 

Data for Smithsonian Institution Allende Meteorite Standard Sample obtained by spark source mass spectrometry. 

P. J. Paulsen, R. Alvarez, and C. W. Mueller, Spark source mass spectrographic analysis of ingot iron for Ag, Cu, Mo, and Ni by isotope dilution and for Co by an internal standard technique, Anal. Chem. 42, 673-675 (1970). 

Spark source (SSMS) and thermal emission (TEMS) mass spectrometry are used to determine ppb to ppm quantities of elements in energy sources such as coal, fuel oil, and gasoline. Toxic metals—cadmium, mercury, lead, and zinc— may be determined by SSMS with an estimated precision of 5%, and metals which ionize thermally may be determined by TEMS with an estimated precision of 1% using the isotope dilution technique. An environmental study of the trace element balance from a coal-fired steam plant was done by SSMS using isotope dilution to determine the toxic metals and a general scan technique for 15 other elements using chemically determined iron as an internal standard. In addition, isotope dilution procedures for the analysis of lead in gasoline and uranium in coal and fly ash by TEMS are presented. 

In spark ablation, a spark at constant density is obtained in a matter of seconds, and thus, particularly in the case of small spark chambers, prebum times are accordingly low. In plasma emission as well as in plasma mass spectrometry a linear dynamic range of more than four orders of magnitude can be obtained and RSDs are a few percent in the case of absolute measurements. However, as shown by the results in Table 6, they can easily fall to below 1%, when using an internal standard element (Fe in the case of steel samples). The matrix effects from the sampling source are low, as will be shown in combination with ICP-OES (see Refs. [242, 248]). They are lower than in arc ablation, as here differences stemming from the thermal volatility of the elements and their compounds play a lesser role. The... 

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