Platform atomization

4 Platform Atomization. A platform is a thin, rectangular shaped piece of graphite (normally prepared from pyrolytic graphite), which is mounted inside the conventional graphite tube. The platform is positioned in the centre of the cuvette. The platform is heated by cuvette wall radiation since it fits into a slot in the wall of the graphite cuvette and therefore does not come into direct contact with the hot centre portion of the tube. 

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Aguilera de Benzo Z, Fraile R, Carrion N, et al. 1989. Determination of lead in whole blood by electrothermal atomization atomic absorption spectrometry using tube and platform atomizers and dilution with Triton X-100. Journal of Analytical and Atmospheric Spectrometry 4 397-400. 

Platform atomization. See Isothermal operation Pneumatic nebulization. See Nebulization... 

Figure 3.1. Platform atomization of Pb in the CRM DORM-2 Fish muscle.

It is apparent from two reports (Subramanian and Meranger. 1985 Neve and Leclerq, 1991) that platform atomization offers no advantage for this determination. A method using platform atomization has been described (Paschal and Bailey, 1987) but no comparison was made with wall atomization. 

Using pyrolytic graphite tubes, platform atomization and integrated absorbance readings a Zeeman-based instrument provides an acceptable situation for selenium determinations and permits most analyses to be performed against matrix matched calibration graphs. In Table 1 recommended procedures for the direct GF-AAS determination of selenium in body fluids are listed. 

For thallium, the detection limits achieved in pure solutions at 276.8 nm are fairly good (about 0.3-0.5/Other cations in large excess, such as Fe and P, also depress the signal (Machata and Binder, 1973). Nitric acid soil extracts could be determined by platform atomization/standard addition without further separation (Hofer et al.. 1990). 

Two principal advantages of the probe atomization are (i) Improved control of the vapour temperature the atoms experience (ii) Rapid heating of the atomization surface to the volatilization temperature of the analyte and matrix. A comparison of typical furnace programmes for wall/platform atomization and probe atomization is given in Table 8. The probe is not in... 

Platform Cuvettes. The concept of platform atomization was first described by L vov in 1978. A platform is a thin rectangular piece of pyrolytic graphite. The platform is positioned within a conventional graphite cuvette as shown in Figure 47. Samples are injected on the platform. Contact... 

Another example of the usefulness of the probe atomization is the determination of lead in urine. Figure 70 shows the peak shapes obtained for an aqueous Pb standard and a urine sample containing the same amounts of lead. The peak shapes and appearance times are totally different for tube wall and platform atomization. Only in the case of probe atomization are the... 

Figure 67 Peak shapes for (A) tube wall and (B) platform atomization...

Platform atomization with high-atomization heating rates... 

This concept should probably be referred to as the stabilized temperature platform atomizer, in line with recent International Union of Pure and Applied Chemists nomenclature recommendations, but will... 

Claeys-Thoreau F. (1982). Determination of low levels of cadmium and lead in biological fluids with simple dilution by atomic absorption spectrophotometry using Zee-man effect background absorption and the L Vov platform. Atomic Spectroscopy, 3,188-191. 

Fernandez, F. J. and Hilligoss, D. (1982) An improved graphite furnace method for the determination of lead in blood using matrix modification and the L vov platform. Atomic Spectrosc., 3, 130-131... 

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