Multielement emission

Comparison with the highest possible values of a multivariate random correlation (see also Section 6.6.3) shows a correlation period of approximately two weeks and two days. This means that sampling of suspended dust at intervals of two weeks is sufficient for the characterization of the average impact of multielement emissions (for all investigated elements simultaneously) at that particular sampling point. 

Multielement Emission Spectrometry Using a Charge-Injection Device Detector... 

Echelle monochromators. In the past 10 years, Echelle monochromators have become increasingly common in multielement emission systems. These are often... 

Multielement atomic absorption spectroscopy is complicated by the need for a multielement emission source. Some multielement hollow cathode lamps are available and continuum sources are possibilities. Another method is to place several hollow cathode lamps along the focal plane of a spectrometer, at positions corresponding to the desired wavelengths, thus permitting all the radiation to emerge from a single slit. In this approach the... 

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. 

Minganti V, Capelli R, Depellegrini R (1995) Evaluation of different derivatization methods for the multielement detection of Hg, Pb and Sn compounds by gas chromatography-microwave induced plasma-atomic emission spectrometry in environmental samples. Fresenius Journal of Analytical Chemistry, 351 (4-5) 471 77. 

Flame and spark emission spectroscopy Not very accurate. Gives multielement analyses 10 = to 10 M... 

Mass spectrometry is the only universal multielement method which allows the determination of all elements and their isotopes in both solids and liquids. Detection limits for virtually all elements are low. Mass spectrometry can be more easily applied than other spectroscopic techniques as an absolute method, because the analyte atoms produce the analytical signal themselves, and their amount is not deduced from emitted or absorbed radiation the spectra are simple compared to the line-rich spectra often found in optical emission spectrometry. The resolving power of conventional mass spectrometers is sufficient to separate all isotope signals, although expensive instruments and skill are required to eliminate interferences from molecules and polyatomic cluster ions. 

One important factor which limits the performance of flame AAS is interference, both spectral and chemical. Spectral interference occurs where emission lines from two elements in the sample overlap. Despite the huge number of possible emission lines in typical multielement samples, it is rarely a problem in AA, unless molecular species (with broad emission bands) are present in the flame (in which case, a higher temperature might decompose the interfering molecule). If spectral interference does occur (e.g., A1 at 308.215 nm, V at 308.211 nm) it is easily avoided by selecting a second (but perhaps less sensitive) line for each element. 

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. 

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. 

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. 

Analytical Techniques Atomic absorption spectrometry, 158, 117 multielement atomic absorption methods of analysis, 158, 145 ion microscopy in biology and medicine, 158, 157 flame atomic emission spectrometry, 158, 180 inductively coupled plasma-emission spectrometry, 158, 190 inductively coupled plasma-mass spectrometry, 158, 205 atomic fluorescence spectrometry, 158, 222 electrochemical methods of analysis, 158, 243 neutron activation analysis, 158, 267. 

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) ... 

The interest in the graphite furnace as an emission source stems from the desire to achieve a multielement detection capability whilst retaining the low limits of detection and the possibility of sample pretreatment. Several... 

KirkbrightjG. F. Sample introduction, signal generation and noise characteristics for argon inductively-coupled plasma optical emission spectroscopy in Instrumentelle Multielement-analyse (ed.) Sansoni, B., Weinheim, VCH 1985... 

Quantitative trace element analysis of diamond by LA-ICP-MS using different synthetic multielement carbon based standards (e.g., cellulose pellets) is discussed by Rege et al 2, whereby 13C was used for internal standardization. Concentrations of 41 elements were determined in two fibrous diamonds from Jwaneng Botswana (JWA 110 and 115) by relative sensitivity coefficients measured using the synthetic cellulose standard. The analytical data were verified by means of instrumental neutron activation analysis (INAA) and proton induced X-ray emission (PIXE).72... 

E. M. Seco-Gesto, A. Moreda-Pineiro, A. Bermejo-Barrera and P. Bermejo-Barrera, Multielement determination in raft mussels by fast microwave-assisted acid leaching and inductively coupled plasma-optical emission spectrometry, Talanta, 72(3), 2007, 1178-1185. 

C. Pena-Farfal, A. Moreda-Pineiro, A. Bermejo-Barrera, P. Bermejo-Barrera, H. Pinochet-Cancino and I. De-Gregori-Henriquez, Ultrasound bath-assisted enzymatic hydrolysis procedures as sample pretreatment for multielement determination in mussels by inductively coupled plasma atomic emission spectrometry, Anal. Chem., 76(13), 2004, 3541-3547. 

L. Ebdon, M. Foulkes and K. O Hanlon, Optimised simultaneous multielement analysis of environmental slurry samples by inductively coupled plasma atomic emission spectrometry using a segmented array charge-coupled device detector. Anal. Chim. Acta, 311, 1995, 123-134. 

The inductively coupled plasma13 shown at the beginning of the chapter is twice as hot as a combustion flame (Figure 21-11). The high temperature, stability, and relatively inert Ar environment in the plasma eliminate much of the interference encountered with flames. Simultaneous multielement analysis, described in Section 21 1. is routine for inductively coupled plasma atomic emission spectroscopy, which has replaced flame atomic absorption. The plasma instrument costs more to purchase and operate than a flame instrument. 

An inductively coupled plasma emission spectrometer does not require any lamps and can measure as many as —70 elements simultaneously. Color Plates 23 and 24 illustrate two designs for multielement analysis. In Plate 23, atomic emission enters the polychromator and... 

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