Atomic absorption spectroscopy screening

HI. Hasegawa, N., Hiroi, A., Shibata, T., Sugino, H., and Kashiwagi, T., Determination of lead in hair by atomic absorption spectroscopy for simple screening of lead intoxication. Annii. Rep. Res. Inst. Environ. Med., Nagoya Univ. 18, 1-5 (1970). 

Lead detection kits are useful as a quick check for screening areas for lead abatement. A positive response is evidence of the presence of lead or a positive interference. A negative response, however, is not conclusive evidence of the absence of lead. The test provides presumptive evidence for the presence of lead, not its absence. A more thorough determination may need to be performed by a quantitative laboratory analysis of any representative bulk material available to substantiate the absence of lead. Samples are analyzed for lead at OSHA s Salt Lake Technical Center (SLTC) using OSHA methods ID-121 with Atomic Absorption Spectroscopy (AAS), ID-125 G with Inductively Coupled Plasma (ICP), or ID-206 (Solders by ICP). If necessary, lower limits of detection for lead may be achieved using ICP Mass Spectrometer procedures. 

The final method of determining depth-distribution information is to compare the surface-sensitive measurements with those from less surface-sensitive or thin-film techniques, such as EDS, WDS, or FTIR, or even with those from purely bulk composition techniques, such as atomic absorption, emission spectroscopy, or neutron-activation analysis. Such comparisons will tell if the constituent in question is localized on the surface, but they will not provide a distribution of constituents nor even information about the thickness of an overlayer, unless it is thick enough (or the bulk is thin enough) that the overlayer is a significant fraction of the sample, or of the detection volume for the thin-film techniques. These comparisons are useful in thick-film analysis or when the bulk of thin-film analysis is used as a screening procedure before surface analysis. 

In deep core level absorption spectroscopies the overlap of the core level wavefunction with the wavefunction of the excited state is of little or no importance. Deep core levels may be regarded as classical charge distributions, completely screened by the inner shells and the photoelectron. Most of the deep core level spectra can therefore be described neglecting many-electron processes. The large spatial overlap of the shallow 4d wayefunction with the 4f wavefunctions, however, favors relaxation processes of the excited atom involving spectacular many-electron effects as the giant resonances . The correlation of these exotic final-state structures... 

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