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  • Author or Editor: C. van Dijk x
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Abstract  

At the laboratory for INAA in Delft, the final approval of the analysis' report partly depends on the quality of the results of simultaneously processed reference materials (RM's). An extensive databank exists holding the information on RM type and analysis conditions. This information can be convented into control charts. The control charts can display (1) an element concentration in one RM as a function of moment of analysis, (2) an element concentrations in one RM as a function of the concentration of an interfering element, (3) an element concentration in all RM's, and (4) the nomalized concentrations of all elements in one RM. The inspection of the various chats facilitates the decision on, e.g., the need for renewed standardization, the fitness-for-use of a RM, any analyst-dependent results, rigidity of the spectrum analysis software etc.

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Abstract  

When slab-shaped samples are analyzed with prompt gamma neutron activation analysis (PGNAA), sensitivity changes can be observed depending on the hydrogen content of the sample. In PGNAA experiments performed by MACKEY at NIST where D2O solutions were compared to H2O solutions, it was found that most elements tested showed statistically equal sensitivity increases with increasing hydrogen concentration. Outliers were manganese, hydrogen and samarium. For manganese, it is hypothesized in this paper that the sensitivity for ions dissolved in D2O is influenced by neutron diffraction due to local ordering of hydrogen bonds. This hypothesis is tested with instrumental activation analysis and falsified.

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