Atomic spectrometry, analytical

Source Optical spectrometry emission absorption fluorescence Mass spectrometry 

Analytical atomic spectrometry nowadays includes the use of flames and plasma discharges for optical and mass spectrometry. The sources are then used directly as 

In atomic absorption spectrometry we need a primary source delivering monochromatic radiation of which the wavelength agrees with that of a resonance line of the elment to be determined. The spectral width must be narrow with respect to the absorption profile of the analyte line. From this point of view atomic absorption 

In the case of atomic absorption and atomic fluorescence the selectivity is thus already partly realized by the radiation source delivering the primary radiation, which in most cases is a line source (hollow cathode lamp, laser, etc.). Therefore, the spectral bandpass of the monochromator is not as critical as it is in atomic emission work. This is especially true for laser based methods, where in some cases of atomic fluorescence a Alter is sufficient, or for laser induced ionization spectrometry where no spectral isolation is required at all. 

For glow discharges and inductively coupled high-frequency plasmas ion generation takes place in the plasmas. In the first case mass spectrometry can be performed directly on solids and in the second case on liquids or solids after sample dissolution. In the various atomic spectrometric methods, real samples have to be delivered in the appropriate form to the plasma source. Therefore, in the treatment of the respective methods extensive attention wUl be given to the techniques for sample introduction. 

Analytical atomic spectrometry nowadays includes the use of flames and plasma discharges for optical and mass spectrometry. The sources are used directly as emission sources or atom reservoirs for atomic absorption or atomic fluorescence or they are used for ion production. In optical atomic spectrometry, atomic emission, absorption, and fluorescence all have their specific possibilities and analytical features. The type of information obtained is clear from the transitions involved (Fig. 6). 

In atomic emission, thermal or electrical energy is used to bring the analyte species to an excited state, from which they return to their ground state through emission of radiation characteristic of all the species present that were sufficiently excited. Thus, from the principle of atomic emission spectrometry it is clearly a 

Applications Basic methods for the determination of halogens in polymers are fusion with sodium carbonate (followed by determination of the sodium halide), oxygen flask combustion and XRF. Crompton [21] has reported fusion with sodium bicarbonate for the determination of traces of chlorine in PE (down to 5 ppm), fusion with sodium bisulfate for the analysis of titanium, iron and aluminium in low-pressure polyolefins (at 1 ppm level), and fusion with sodium peroxide for the complexometric determination using EDTA of traces of bromine in PS (down to 100ppm). Determination of halogens in plastics by ICP-MS can be achieved using a carbonate fusion procedure, but this will result in poor recoveries for a number of elements [88]. A sodium peroxide fusion-titration procedure is capable of determining total sulfur in polymers in amounts down to 500 ppm with an accuracy of 5% [89]. 

In this chapter, only atomic spectrochemical methods are discussed. Atomic spectra are line spectra, and are specific to the absorbing or emitting atoms (elements), i.e. the spectra contain information on the atomic structure. Each spectral line can be regarded as the difference between two atomic states  

Atomic spectra are much simpler than the corresponding molecular spectra, because there are no vibrational and rotational states. Moreover, spectral transitions in absorption or emission are not possible between all the numerous energy levels of an atom, but only according to selection rules. As a result, emission spectra are rather simple, with up to a few hundred lines. For example, absorption and emission spectra for sodium consist of some 40 peaks for elements with several outer electrons, absorption spectra may be much more complex and consist of hundreds of peaks. 

Atomisation method Typical atomisation temperature (K) Basis for method11 

Both emission and absorption spectra are affected in a complex way by variations in atomisation temperature. The means of excitation contributes to the complexity of the spectra. Thermal excitation by flames (1500-3000 K) only results in a limited number of lines and simple spectra. Higher temperatures increase the total atom population of the flame, and thus the sensitivity. With certain elements, however, the increase in atom population is more than offset by the loss of atoms as a result of ionisation. Temperature also determines the relative number of excited and unexcited atoms in a source. The number of unexcited atoms in a typical flame exceeds the number of excited ones by a factor of 103 to 1010 or more. At higher temperatures (up to 10 000 K), in plasmas and electrical discharges, more complex spectra result, owing to the excitation to more and higher levels, and contributions of ionised species. On the other hand, atomic absorption and atomic fluorescence spectrometry, which require excitation by absorption of UV/VIS radiation, mainly involve resonance transitions, and result in very simple spectra. 

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A. Montaser and D. W. GoHghdy, eds.. Inductively Coupled Plasmas in Analytical Atomic Spectrometry, 2nd ed., VCH PubHshers, New York, 1992. 

Prange A, Jantzen E (1995) Determination of organometallic species using GC-ICP-MS. Journal of Analytical Atomic Spectrometry, 10 105-109. 

Bysouth, S. R., and Tyson, J. R, A Comparison of Curve Fitting Algorithms for Hame Atomic Absorption Spectrometry, Journal of Analytical Atomic Spectrometry, 1, February 1986, 85-87. 

Williams, M. and Plepmeler, . H. "Commercial Tungsten Filament Atomizer for Analytical Atomic Spectrometry". 

Element analytical pretreatment 8.3 Analytical atomic spectrometry 605... 

Atomic spectroscopy has been reviewed [92] a recent update is available [93]. An overview of sample introduction in atomic spectrometry is available [94]. Several recent books deal with analytical atomic spectrometry [95-100],... 

After Resano et al. [413]. From M. Resano et al., Journal of Analytical Atomic Spectrometry, 15, 389-395 (2000). Reproduced by permission of The Royal Society of Chemistry. 

J. A.C. Broekaert, Analytical Atomic Spectrometry with Flames... 

L. Ebdon, E.H. Evans, A. Fisher and S. Hill (eds), An Introduction to Analytical Atomic Spectrometry, John Wiley Sons, Ltd, Chichester (1998). 

Delves HT, Campbell MJ. 1988. Measurements of total lead concentrations and of lead isotope ratios in whole blood by use of inductively coupled plasma source mass spectrometry. J Analytical Atomic Spectrometry 3 343-348. 

Xu Y, Liang Y. 1997. Combined nickel and phosphate modifier for lead determination in water by electrothermal atomic absorption spectrometry. Journal of Analytical Atomic Spectrometry 12(4) 471-474. 

R. Van Ham, L. Van Vaeck, A. Adriaens, F. Adams, B. Hodges and G. Groenewold, Inorganic speciation in static SIMS a comparative study between monatomic and polyatomic primary ions, Journal of Analytical Atomic Spectrometry, 17, 753 758 (2002). 

Walder, A.J. and Freedman, P.A. (1992). Isotopic ratio measurement using a double focusing magnetic sector mass analyser with an inductively coupled plasma as an ion source. Journal of Analytical Atomic Spectrometry 1 571-575. 

Clayton, R., Andersson, P., Gale, N.H., Gillis, C. and Whitehouse, MJ. (2002). Precise determination of the isotopic composition of Sn using MC-ICP-MS. Journal of Analytical Atomic Spectrometry 17 1248-1256. 

Journal of Analytical Atomic Spectrometry Applied Spectroscopy Spectrochimica Acta Part B... 

Jackson, K. W. (1999). Electrothermal Atomization for Analytical Atomic Spectrometry. Chichester, Wiley. 

Perezarantegui, J., Querre, G., and Castillo, J. R. (1994). Particle-induced X-ray-emission -thick-target analysis of inorganic materials in the determination of light-elements. Journal of Analytical Atomic Spectrometry 9 311-314. 

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 major goals for the future development of analytical atomic spectrometry measurements are improved detection Hmits and the development of simple ways of couphng to other analytical techniques. The nebuHzer systems of the spectrometric instruments are the parts that need to be improved in order to achieve these goals. Typically, nebuHzer efficiencies are of the order of 1—2%, and, as a result, they are Hmiting factors for instruments which can cost between 100,000 and 150,000. 

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