Spark source mass

SRM. selected reaction monitoring SSMS. spark source mass spectrometry... 

Spark Source Mass Spectrometry (SSMS) is a method of trace level analysis—less than 1 part per million atomic (ppma)—in which a solid material, in the form of two conducting electrodes, is vaporized and ionized by a high-voltage radio frequency spark in vacuum. The ions produced from the sample electrodes are accelerated into a mass spectrometer, separated according to their mass-to-charge ratio, and collected for qualitative identification and quantitative analysis. 

Figure 1 Schematic diagram of a Mattauch-Herzog geometry spark source mass spectrometer using an ion-sensitive plate detector.

Qualitatively, the spark source mass spectrum is relatively simple and easy to interpret. Most instrumentation has been designed to operate with a mass resolution Al/dM of about 1500. For example, at mass M= 60 a difference of 0.04 amu can be resolved. This is sufficient for the separation of most hydrocarbons from metals of the same nominal mass and for precise mass determinations to identify most species. Each exposure, as described earlier and shown in Figure 2, covers the mass range from Be to U, with the elemental isotopic patterns clearly resolved for positive identification. 

C. W. Magee. Critical Parameters Affecting Precision and Accuracy in Spark Source Mass Spectrometry with Electrical Detection. PhD thesis, Univetsity of Virginia, University Microfilms, Ann Arbot, MI, 1973. 

Because GDMS can provide ultratrace analysis with total elemental coverage, the technique fills a unique analytical niche, supplanting Spark-Source Mass Spectrometry (SSMS) by supplying the same analysis with an order-of-magnitude better accuracy and orders-of-magnitude improvement in detection limits. GDMS analy-... 

Spark Source Mass Spectrometry Spark Source Mass Spectrometry... 

H. Kramer, S. Semel J.E. Abel, Trace Elemental Survey Analysis of Trinitrotoluene , PATR 4767 (1975) (An evaluation of the applicability of spark source mass spectrometry and thermal neutron activation for the detn of origin-related trace elemental impurities in TNT) 10) C. Ribando J. Haber-man, Origin-Identification of Explosives Via Their Composite Impurity Profiles I. The... 

Neutron Activation Analysis X-Ray Fluorescence Particle-Induced X-Ray Emission Particle-Induced Nuclear Reaction Analysis Rutherford Backscattering Spectrometry Spark Source Mass Spectrometry Glow Discharge Mass Spectrometry Electron Microprobe Analysis Laser Microprobe Analysis Secondary Ion Mass Analysis Micro-PIXE... 

Principles and Characteristics The original idea of spark-source mass spectrometry (SSMS) is due to Dempster [356], long before the first commercial instruments. In spark-source MS, atomisation and ionisation... 

Applications Real applications of spark-source MS started on an empirical basis before fundamental insights were available. SSMS is now considered obsolete in many areas, but various unique applications for a variety of biological substances and metals are reported. Usually, each application requires specific sample preparation, sparking procedure and ion detection. SSMS is now used only in a few laboratories worldwide. Spark-source mass spectrometry is still attractive for certain applications (e.g. in the microelectronics industry). This is especially so when a multi-element survey analysis is required, for which the accuracy of the technique is sufficient (generally 15-30% with calibration or within an order of magnitude without). SSMS is considered to be a... 

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. 

FMW Focused microwave-enhanced GSSMS Gliding spark source mass... 

Table 5.6 compares the ICP-AES results with data generated for the same sample by two other independent methods - isotope dilution spark source mass spectrometry (IDSSMS), and graphite furnace atomic absorption spectrometry (GFAAS). The IDSSMS method also uses 25-fold preconcentration of the metals and matrix separation using the ion exchange procedure, following isotope... 

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

The earlier stable isotope dilution mass spectrographic work was accomplished with a thermal ion mass spectrometer which had been specifically designed for isotope abundance measurements. However, Leipziger [829] demonstrated that the spark source mass spectrometer could also be used satisfactorily for this purpose. Although it did not possess the excellent precision of the thermal unit, Paulsen and coworkers [830] pointed out that it did have a number of important advantages. 

The thermal ion mass spectrometer was specifically developed for the measurement of isotope abundances and is capable of excellent precision. Although the spark source mass spectrometer used in this work lacks some of this precision, it has proved very useful in stable isotope dilution work. It has a number of advantages, including greater versatility, relatively uniform sensitivity, and better applicability to a wide range of elements. 

Heavy Metals, Isotope Dilution, Spark Source Mass Spectrometry, and Inductively Coupled Plasma Atomic Emission Spectrometry... 

A logical approach which serves to minimise such uncertainties is the use of a number of distinctly different analytical methods for the determination of each analyte wherein none of the methods would be expected to suffer identical interferences. In this manner, any correspondence observed between the results of different methods implies that a reliable estimate of the true value for the analyte concentration in the sample has been obtained. To this end Sturgeon et al. [21] carried out the analysis of coastal seawater for the above elements using isotope dilution spark source mass spectrometry. GFA-AS, and ICP-ES following trace metal separation-preconcentration (using ion exchange and chelation-solvent extraction), and direct analysis by GFA-AS. These workers discuss analytical advantages inherent in such an approach. 

Identification and structural analysis of organic compounds. Determination of trace impurities in a wide range of inorganic materials (spark source mass spectrometry). 

Spark source mass spectrometry is used for the examination of non-volatile inorganic samples and residues to determine elemental composition. An RF spark of about 30 kV is passed between two electrodes, one of which may be the sample itself, causing vaporization and ionization. Powdered samples or residues from ashed organic materials can be formed into an electrode after mixing with pure graphite powder. 

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