Multielement analysis

Multielement analysis, excellent detection limits for heavy metals quantitative measurement of heavy-metal trace contamination on silicon wafers... 

In Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), a gaseous, solid (as fine particles), or liquid (as an aerosol) sample is directed into the center of a gaseous plasma. The sample is vaporized, atomized, and partially ionized in the plasma. Atoms and ions are excited and emit light at characteristic wavelengths in the ultraviolet or visible region of the spectrum. The emission line intensities are proportional to the concentration of each element in the sample. A grating spectrometer is used for either simultaneous or sequential multielement analysis. The concentration of each element is determined from measured intensities via calibration with standards. 

The Inductively Coupled Plasma (ICP) has become the most popular source for multielement analysis via optical spectroscopy since the introduction of the first commercial instruments in 1974. About 6000 ICP-Optical Emission Spectrometry (ICP-OES) instruments are in operation throughout the world. 

ICP-OES is one of the most successful multielement analysis techniques for materials characterization. While precision and interference effects are generally best when solutions are analyzed, a number of techniques allow the direct analysis of solids. The strengths of ICP-OES include speed, relatively small interference effects, low detection limits, and applicability to a wide variety of materials. Improvements are expected in sample-introduction techniques, spectrometers that detect simultaneously the entire ultraviolet—visible spectrum with high resolution, and in the development of intelligent instruments to further improve analysis reliability. ICPMS vigorously competes with ICP-OES, particularly when low detection limits are required. 

G. M. Levy, A. Quaglia, R, E. Lazure, and S. W. McGeorge. Spect. Acta. 42B, 341, 1987. Describes the diode array-based spectrally segmented spectrometer for simultaneous multielement analysis. 

Monochromator 663, 791 Monodentate ligand 51 Morphine (and codeine) D. of (fu) 740 Mortar agate, 155 mullite, 155 percussion, 155 synthetic sapphire, 155 Muffle furnace 97 Multielement analysis 174, 184, 775 Multiple range indicators 268 Murexide 316... 

XiE M, Von Bohlen A, Klockenkamper R, Jian X, Gunther K (1998) Multielement analysis of Chinese tea (Camellia sinensis) by total reflection X-ray fluorescence. Z Lebensm Unters Forsch 207A 3i-38. 

The preponderance of work on multielement analysis in seawaters has been carried out using the graphite furnace technique, as this has the additional sensitivity over the direct technique that is required in seawater analysis. 

Chong et al. [742] have described a multielement analysis of multicomponent metallic electrode deposits, based on scanning electron microscopy with energy dispersive X-ray fluorescence detection, followed by dissolution and ICP-MS detection. Application of the method is described for determination of trace elements in seawater, including the above elements. These elements are simultaneously electrodeposited onto a niobium-wire working electrode at -1.40 V relative to an Ag/AgCl reference electrode, and subjected to energy dispersive X-ray fluorescence spectroscopy analysis. Internal standardisation... 

Karbe, L., C. Schnier, and H.O. Siewers. 1977. Trace elements in mussels (Mytilus edulis) from coastal areas of the North Sea and the Baltic. Multielement analysis using instrumental neutron activation analysis. Jour. Radioanal. Chem. 37 927-943. 

Rouchaud, J.D., Boisseau, N. and Federoff, M. (1993). Multielement analysis of aluminium by NAA and ICP/AES. Journal of Radioanalytical and Nuclear Chemistry Letters 175 25-31. 

N. Jakubowski, D. Stuewer and W. Vieth, Performance of a glow discharge mass spectrometer for simultaneous multielement analysis of steel, Anal. Chem., 59 (1987) 1825-1830. 

Segal, I., Kloner, A., and Brenner, I. B. (1994). Multielement analysis of archaeological bronze objects using inductively coupled plasma-atomic emission spectrometry -aspects of sample preparation and spectral-line selection. Journal of Analytical Atomic Spectrometry 9 737-744. 

Unlike a flame, in which only a very limited number of metals emit light because of the low temperature, virtually all metals present in a sample emit their line spectrum from the ICP torch. Not only does this make for a very broad application for ICP, but it also means that a given sample may undergo very rapid and simultaneous multielement analysis. With this in mind, it is interesting to consider the options for the optical path for the ICP instrument. 

The advantage of ICP is that the emissions are of such intensity that it is usually more sensitive than flame AA (but less sensitive than graphite furnace AA). In addition, the concentration range over which the emission intensity is linear is broader. These two advantages, coupled with the possibility of simultaneous multielement analysis offered by the direct reader polychromator design, make ICP a very powerful technique. The only real disadvantage is that the instruments are more expensive. See Workplace Scene 9.3. 

ICP Light emitted by atoms and monoatomic ions in an inductively coupled plasma is measured A popular technique useful over a broad concentration range multielement analysis is possible instruments are costly... 

Advantages 1) more sensitive, 2) broader concentration range measurable, and 3) multielement analysis possible. Disadvantages cost. 

A brief comment on dimensionality is in order at this point. As used here, the number of dimensions is taken equal to the number of subscripts on the data matrix. Thus, an optical or mass or nuclear spectrum is one-dimensional, but if different samples or sampling times are involved it is considered two-dimensional, as in GC-MS. In this context, we treat the vector representation of a spectrum or a multielement analysis as single dimension, though it is frequently viewed as "a point in hyperspace."... 

Nielson, K.K., Sanders, R.W. 1983. Multielement analysis of unweighed biological and geological samples using backscatter and fundamental parameters. Advances in X-Ray Analysis 1983, 26, 385-390. 

Chapters 7 and 8 describe two major techniques for the monitoring of trace elements in environmental samples atomic absorption (AA) and inductively coupled plasma-atomic emission spectroscopy (ICP). AA is most ideally suited for analyses where a limited number of trace metal concentrations are needed with high accuracy and precision. ICP has the advantage of multielement analysis with high speed. 

Brzezinska-Paudyn A, VanLoon JC, Balicki MR. 1986. Multielement analysis and mercury speciation in atmospheric samples from the Toronto area. Water Air Soil Pollut 27 45-56. 

Methods of characterization of the solid, e.g. by X-ray diffraction techniques, have been improved and complemented by multielement analysis of impurities. 

Actinide metal samples are characterized by chemical and structure analysis. Multielement analysis by spark source mass spectrometry (SSMS) or inductively coupled argon plasma (ICAP) emission spectroscopy have lowered the detection limit for metallic impurities by 10 within the last two decades. The analysis of O, N, H by vacuum fusion requires large sample, but does not distinguish between bulk and surface of the material. Advanced techniques for surface analysis are being adapted for investigation of radioactive samples (Fig. 11) ... 

Because of its capability for rapid multielement analysis, ICP-MS is particularly suited to sample introduction methods which give rise to transient signals. For example, electrothermal vaporization, flow injection and chromatographic methods can be interfaced and many elements monitored in a single run (see Chapter 7). 

A Enantioselective multidimensional gas chromatography (MDGC)-mass spectrometry (MS), B gas chromatography (GC)-isotope ratio mass spectrometry (IRMS) multielement analysis (5 C, values), C enantiomeric purity (%), D total percentage (%)... 

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