Spark AES

Arc and spark AES have found wide use for the analysis of solids and are still important methods for routine analysis, especially when many elements have to be determined in numerous samples. 

Spark AES has also been used for oil analysis. Here the oil is sampled by a rotating carbon electrode. Also electrically non-conducting powders can be analyzed after mixing them with graphite powder and briquetting. 

Dual Laminate (Fluoropolymer-lined FRP) Same as Adhesive-bonded Fabricate liner first on a mandrel (hand and machine welding) and build FRP laminate over the liner. Use carbon cloth for spark testing Shop and Field Pressure OK (RTP-1 Dual lam) Vacuum OK for FRP/fluoropolymer bond. Design FRP for vacuum 33 dia max Visual Spark AE CRBBD Possible Testing recommended... 

Analytic Jena AG, Germany AAS Fisher Scientific, USA AAS GBC, Australia TOF-ICP-MS, AAS Hitachi, Japan ICP-AES. AAS, ICP-MS PerkinElmer Instruments (incorporating Princeton Applied Research, ORTEC, Signal Recovery and Berthold products). USA AAS, ICP-OES, ICP-MS. GC. GC/MS Shimadzu. Japan arc/spark AES. ICP-AES, AAS... 

Agilent Technologies (formerly Hewlett Packard), USA ICP-MS, MIP-AES Baird Atomic, USA arc/spark AES. ICP-AES, AAS... 

The main detectors used in AES today are photomultiplier tubes (PMTs), photodiode arrays (PDAs), charge-coupled devices (CCDs), and vidicons, image dissectors, and charge-injection detectors (CIDs). An innovative CCD detector for AES has been described [147]. New developments are the array detector AES. With modem multichannel echelle spectral analysers it is possible to analyse any luminous event (flash, spark, laser-induced plasma, discharge) instantly. Considering the complexity of emission spectra, the importance of spectral resolution cannot be overemphasised. Table 8.25 shows some typical spectral emission lines of some common elements. Atomic plasma emission sources can act as chromatographic detectors, e.g. GC-AED (see Chapter 4). 

Applications Atomic emission spectrometry has been used for polymer/additive analysis in various forms, such as flame emission spectrometry (Section 8.3.2.1), spark source spectrometry (Section 8.3.2.2), GD-AES (Section 8.3.2.3), ICP-AES (Section 8.3.2.4), MIP-AES (Section 8.3.2.6) and LIBS. Only ICP-AES applications are significant. In hyphenated form, the use of element-specific detectors in GC-AED (Section 4.2) and PyGC-AED deserves mentioning. 

GDS instruments are viable alternatives to the traditional arc and spark-source spectroscopies for bulk metals analysis. Advantages of GDS over surface analysis methods such as AES, XPS and SIMS are that an ultrahigh vacuum is not needed and the sputtering rate is relatively high. In surface analysis, GD-OES, AES, XPS and SIMS will remain complementary techniques. GD-OES analysis is faster than AES (typically 10 s vs. 15 min). GD-OES is also 100 times more sensitive than... 

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. 

SS-AES Sliding spark-source atomic emission spectrometry... 

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... 

For spectra corresponding to transitions from excited levels, line intensities depend on the mode of production of the spectra, therefore, in such cases the general expressions for moments cannot be found. These moments become purely atomic quantities if the excited states of the electronic configuration considered are equally populated (level populations are proportional to their statistical weights). This is close to physical conditions in high temperature plasmas, in arcs and sparks, also when levels are populated by the cascade of elementary processes or even by one process obeying non-strict selection rules. The distribution of oscillator strengths is also excitation-independent. In all these cases spectral moments become purely atomic quantities. If, for local thermodynamic equilibrium, the Boltzmann factor can be expanded in a series of powers (AE/kT)n (this means the condition AE < kT), then the spectral moments are also expanded in a series of purely atomic moments. 

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