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  • Author or Editor: J. Török x
  • Chemistry and Chemical Engineering x
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Abstract  

Based on the method of SAMSAHL a programmed, semi-automated processing system has been developed and tested for the neutron activation analysis of the following elements: As, Se, Sb, Br, Sn and Te. The main characteristics of the procedure are the following: wet ashing of the sample (by means of digestion in a mixture of concentrated sulphuric acid and hydrogen peroxide), bromination, and chlorination. The procedure is controlled via the appropriate dosage of the reagents and a carefully managed thermal balance. The chemical yield and its reproducibility were determined by tracer techniques using exactly the same parameters as for the active runs. According to the results the method can be used for the routine determination of the given elements except antimony.

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Abstract  

We have been working on mercury collection from flue gas by amalgamation and subsequent XRF analysis. Previous results showed unexpectedly high relative standard deviation (30%) in collection efficiency when silver-coated filters were exposed to gas phase mercury in a pilot-scale test chamber. Filters were analyzed by micro-XRF, TXRF and conventional XRF to explore the source of scattering. It was concluded that mercury had inhomogeneously adsorbed in the filter as the cause of this variation, leading to a positive bias of 50% in efficiency value. Results reported in this paper suggest the TXRF method is accurate to within ±10% when X-ray counting statistics are not the limiting factor. Application of this filter in flue gas measurement will be presented.

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