Direct spectrometric analysis of solid samples

Adapted from Moenke-Blankenburg [217]. From L. Moenke-Blanken-burg, in Lasers in Analytical Atomic Spectroscopy (J. Sneddon et al., eds), VCH Publishers, New York, NY (1997), pp. 125-195. Reproduced by permission of Wiley-VCH. 

The influence of matrix concomitants often cannot be recognised or quantified. Progress in background correction techniques (e.g. direct Zeeman-AAS [218]), furnace techniques, microweighing, and electronic signal processing have gradually made possible the elimination 

Different analytical procedures have been developed for direct atomic spectrometry of solids applicable to inorganic and organic materials in the form of powders, granulate, fibres, foils or sheets. For sample introduction without prior dissolution, a sample can also be suspended in a suitable solvent. Slurry techniques have not been used in relation to polymer/additive analysis. The required amount of sample taken for analysis typically ranges from 0.1 to 10 mg for analyte concentrations in the ppm and ppb range. In direct solid sampling method development, the mass of sample to be used is determined by the sensitivity of the available analytical lines. Physical methods are direct and relative instrumental methods, subjected to matrix-dependent physical and nonspectral interferences. Standard reference samples may be used to compensate for systematic errors. The minimum difficulties cause INAA, SNMS, XRF (for thin samples), TXRF and PIXE. 

Hybrid systems which have been used to determine metals in solids include ETV-ICP, spark-MIP, spark-flame, arc-flame, laser-flame, laser-ETA and laser-DCP. ETV-ICP-MS is a solid sampling process which is automated, multi-element with high detection power, and amongst the best currently achieved. 

Direct solid sample analysis is still mostly a subsidiary method, confined to specific analytical tasks, rather than truly complementary to traditional analysis via solutions. Solid sampling is not standard in routine 

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