Flame atomic emission spectrometry FAES

Flames (temperatures from 1700°C to 3100°C) and plasmas (temperatures ranging between 4000°C and 6000°C) are very efficient means of atomization they are used in FAAS, flame atomic emission spectrometry (FAES), ICP-OES, and ICP-MS. High temperatures (up to 3000°C) can also be obtained if an intense electrical current is set up between two electrical contacts. This type of atomization by electrical heating (electrothermal atomization) is the basis of ETA AS. 

For instance, those elements present at relatively high concentration levels in milk are usually determined by FAAS or flame atomic emission spectrometry (FAES). On the other hand, if better LoDs are needed (e.g., ng g-1), the technique of choice would be ET-AAS. For multielemental analysis plasma-based techniques are recommended, such as AES for major elements and trace elements, or, as described below, mass spectrometry (MS) for major, trace, and ultratrace elements. The most relevant applications of these atomic techniques for elemental analysis in milk samples are summarized in Table 13.7. 

Emission spectrometry using chemical flames (flame atomic emission spectrometry, FAES) as excitation sources is the earlier counterpart to flame atomic absorption spectrometry. In this context emission techniques involving arc/spark and direct or inductively coupled plasma for excitation are omitted and treated separately. Other terms used for this technique include optical emission, flame emission, flame photometry, atomic emission, and this technique could encompass molecular emission, graphite furnace atomic emission and molecular emission cavity analysis (MEGA). 

Tests for certain metals can be carried out conveniently on solutions using flame atomic emission spectrometry (FAES) or flame atomic absorption spectrometry (FAAS), if the appropriate apparatus is available. These tests will be described under Section 2.7. 

In flame atomic emission spectrometry (FAES) the sample solution is sprayed into a flame, and by means of a monochromator the emitted radiation is analysed. As the emission spectrum is characteristic for each element, by identifying the wavelengths of the lines in the spectrum, the presence or absence of a metal can thus be established. 

Sodium is determined in physiological samples using flame atomic emission spectrometry (FAES), UV-visible spectrophotometry, or potentiometry. All the methods can be used for serum (for convenience and brevity, serum here includes plasma obtained from heparinized blood) or urine, whereas blood can only... 

Analytical systems that measure substance concentrations in moles per liter of plasma, e.g., atomic [ 5] absorption spectrometry (AAS) and flame atomic emission spectrometry (FAES), coexist with determinations of relative ion activity in undiluted and diluted samples. In consequence a system of computing and reporting results of sodium and potassium ions was proposed by the International Federation of Clinical Chemistry (IFCC) to convert the results of direct ISE assays to FAES/AAS and vice versa. 

The flame atomic emission spectrometry (FAES) was used by us to measure the com-plexing ability of tested compound. The flame photometiy constitutes the relatively sensitive method which allows the determination of studied element concentrations in the range of 0.1-1000 ppm with a relative small error of 1-3 %. This approach was used for the determination of the calcium concentration in the water solution over solid calcium oxalate i.e. the shift of the solid-hquid interphase equiUbrium in and without the presence of synthetic or natural complexing agent [45-47],... 

Among the spectrometric methods used to determine metal concentrations, FAAS is particularly useful to perform water analysis (Figure 11.1). It is a relatively inexpensive method, which presents an adequate sensitivity sufficiently high for the determination of major metals in most of aquatic systems. Considering that most of atomic absorption instruments are also equipped to operate in an emission mode, large number of alkali metals (i.e., Na, K) are typically determined by flame photometry or flame atomic emission spectrometry (FAES) due to their relatively low excitation and simplicity of the emission techniques. This technique is relatively free from spectral interferences, and considering its versatility and simplicity of operation, it has become the most extensively used method for the determination of metals within water samples. 

FAES flame atomic emission spectrometry FANES furnace atomic non-thermal excitation spectrometry... 

Flame atomic emission spectrometry Basic information on FAES is presented elsewhere in this encyclopedia. Sodium measurements are performed at 590 nm with the use of a propane flame (1925°C). Physiological samples for sodium determination are highly diluted before measurement. The diluent and the calibrator solution contain the same concentration of lithium ions so as to balance flame instability by a concomitant measurement of lithium in the reference beam (the so-called lithium guideHne). At the same time, lithium ions inhibit the ionization of sodium atoms. This procedure cannot be used in the case of therapy with lithium salts. That is why some authors prefer the concomitant measurement of caesium to that of lithium. Dilution adjusts the viscosity of the sample to that of the calibrator solution to produce identical aspiration rate and drop size on nebulization. As other electrolytes interfere with sodium measurement, their concentration in the caH-brator solution must be similar to their concentration in the sample. For the measurement of sodium in urine, calibrator solutions different from those for serum measurement are needed as the electrolyte concentrations in urine samples are quite different from those in serum and their relations are very variable. As the concentration of the electrolytes in serum is rather constant, calibrator solutions for serum measurements can fulfill their function better than those for urine in other words, urine determinations are usually less accurate. FAES proved to be sufficiently reliable to be used as the basic principle of the sodium reference measurement procedure. In routine use, however, FAES is less accurate. Its application is given up by most clinical laboratories in favor of potentiometric measurements... 

Flame atomic emission spectrometry Although FAES is not as reliable as FAAS, it was widely used because it allows the simultaneous mechanized determination of sodium, potassium, and calcium with adequate analytical performance for routine laboratory work. As calcium is not as easily excitable as the alkali metals, an air-acetylene flame (2325°C) instead of an air-propane flame must be used, which is less appropriate for the measurement of sodium and potassium. The flame spectrum of calcium has emissions at 422.7, 554, and 622 nm, the first being an arc line and the others being molecular bands. Usually 622 nm (CaO) is chosen for measurement. Errors from anionic interference due to phosphate salts, which are not easily volatilized, can be excluded by the addition of phosphate ions in excess. For further details, see Sodium above. 

Flame atomic emission spectrometry Magnesium has a flame spectrum with a band emission with peaks at 370 nm and 383 nm and an arc line at 285.2 nm. Wavelengths of 370 nm or 383 nm have been proposed for FAES, but the method is only rarely applied. 

Flame Atomic Absorption and Atomic Emission Spectrometry (FAAS and FAES)... 

Flame Atomic Emission /Absorption Spectrometry FAES has been applied in milk samples for the determination of the major elements K and Na [35, 36]. Other elements such as Sr can be also determined by FAES [37]. 

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