Atomic emission multielement detection

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. 

Microwave-induced plasma (MIP), direct-current plasma (DCP), and inductively coupled plasma (ICP) have also been successfully utilized. The abundance of emission lines offer the possibility of multielement detection. The high source temperature results in strong emissions and therefore low levels of detection. Atomic absorption (AA) and atomic fluorescence (AF) offer potentially greater selectivity because specific line sources are utilized. On the other hand, the resonance time in the flame is short, and the limit of detectability in atomic absorption is not as good as emission techniques. The linearity of the detector is narrower with atomic absorption than emission and fluorescence techniques. 

In the struggle for supremacy in the area of multielement atomic emission, the recent advent of the induction-coupled plasma (1 -9 ) may result in the eventual extinction of combustion flames as spectroscopic sources. In the area of detection systems, numerous configurations have been proposed, and, at this time, it is... 

Inductively coupled plasma-atomic emission spectrometry was investigated for simultaneous multielement determinations in human urine. Emission intensities of constant, added amounts of internal reference elements were used to compensate for variations in nebulization efficiency. Spectral background and stray-light contributions were measured, and their effects were eliminated with a minicomputer-con-trolled background correction scheme. Analyte concentrations were determined by the method of additions and by reference to analytical calibration curves. Internal reference and background correction techniques provided significant improvements in accuracy. However, with the simple sample preparation procedure that was used, lack of sufficient detecting power prevented quantitative determination of normal levels of many trace elements in urine. 

Atomic emission spectroscopy apparatus, 77,78-79t,80 procedure, 77,78-79t,80 multielement detection, 75 SIT, 31-56... 

An AED detector is a multielement detector capable of detecting elements with atomic emission lines in the vacuum UV, UV-VIS, and near IR portions of the electromagnetic spectrum. 

For the practical analysis of Ni in biological materials, GF-AAS techniques are by far the most important, and for biological fluids demand only very simple steps for sample preparation. Voltammetrio methods can provide lower detection limits in specially prepared samples, while less sensitive methods such as inductively coupled plasma-atomic emission spectrometry (ICP-AES) may be useful in multielement protocols with tissues and other solid samples. 

Atomic emission spectroscopy with inductive coupled exitation (ICP-AES), although quite costly, is important for multielement determination with high sample rate. Neutron activation analysis (NAA) is a powerful detection method but costly in terms of both financial and work expenditures. X-ray fluorescence (XRF) methods are perfect multielement methods with high sampling rate. ICP-MS is also applied. 

Atomic spectrometric techniques such as flame atomic absorption spectrometry (FAAS), electrothermal AAS (ETAAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), and ICP-MS are used for the determination of elements, particularly metals. ICP-MS is the most sensitive, typically with microgram per liter detection limits and multielement capability but it has high start-up and operating costs. UV-visible spectrophotometry is also used for the determination of metal ions and anions such as nitrate and phosphate (usually by selective deriva-tization). It is a low cost and straightforward technique, and portable (handheld) instruments are available for field deployment. Flow injection (FI) provides a highly reproducible means of manipulating solution chemistry in a contamination free environment, and is often used for sample manipulation, e.g., derivatization, dilution, preconcentration and matrix removal, in conjunction with spectrometric detection. Electroanalytical techniques, particularly voltammetry and ion-selective electrodes (ISEs), are... 

Atomic absorption spectrometry is commonly used to measure a wide range of elements as shown in Table 2. Such techniques as flame, graphite furnace, hydride generation, and cold vapor are employed. Measurements are made separately for each element of interest in turn to achieve a complete analysis these techniques are relatively slow to use. More sensitive, but also more expensive, multielement analytical techniques such as inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry can be used if lower (pgl and below) detection limits are required. These detectors can also be coupled with separation systems if speciation data, e.g., Cr(III) and Cr(VI), are needed. 

Multichannel spectrometers which allow the simultaneous determination of a large number of elements, as in atomic emission spectrometry have not encountered a breakthrough in AAS yet. However, over a number of years, work with high-intensity continuous sources and high-resolution echelle spectrometers for multielement AAS determinations has aroused some interest [160]. Fourier transform spectrometry and multichannel detection with photodiode arrays has opened new perspectives for the simultaneous detection of... 

Atomic absorption remains a staple of forensic chemistry, given its low cost, simple operation, and easy maintenance. The limitations are related to versatility. Unless multielement lamps are used, only one element can be tested for at a time, and each element requires a separate lamp and instrument optimization. For small target lists such as a list of barium, antimony, and lead for GSR, this is not onerous, but still is inconvenient. Limits of detection are in the low-ppm to high-ppb range for most elements, As a result, a few forensic laboratories have turned to inductively coupled plasma atomic emission spectroscopy (ICP-AES) for additional elemental analysis capability. 

The roots of ICP-MS began in the mid-1960s with the advent of a technique called inductively couple plasma—atomic emission spectrometry (ICP-AES). For decades, prior to this, atomic emission spectrometry (flame, direct current-arc, and controUed-waveform spark) was the predominant method used for elemental analysis. The work of Greenfield et al. (1964) and work done essentially simultaneously by Wendt and Fassel (1965) introduced an emission spectrometric technique that provided high sensitivity trace element analysis with a multielement detection capability. This technique is still widely used today and can be studied in publications by Boumans (1987) and Montaser and Golightly (1992). 

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. 

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