by

Nuclear Activation AMS

Recently, I have been cooperating with the VERA laboratory on dedecting minute amounts of Chlorine in steel [1]. Usually, the detection of Cl is easily done by regular Neutron Activation Analysis (see e.g. [2, 3]), in this case the very small amount of chlorine in combination with the interference from the matrix (Fe) made it necessary to find new ways of detection.

What we came up with is the idea [1] of using the long-lived isotope 36Cl that can be created by neutron capture from the stable 35Cl and measure it after dissolution of the samples by AMS.

For all the dirty details, check out the article!

References

[1] [doi] S. R. Winkler, R. Eigl, O. Forstner, M. Martschini, P. Steier, J. H. Sterba, and R. Golser, “Using the nuclear activation ams method for determining chlorine in solids at ppb-levels and below,” Nuclear instruments and methods in physics research section b: beam interactions with materials and atoms, p. –, 2015.
[Bibtex]
@Article{Winkler2015,
Title = {Using the nuclear activation AMS method for determining chlorine in solids at ppb-levels and below},
Author = {Winkler, Stephan R. and Eigl, Rosmarie and Forstner, Oliver and Martschini, Martin and Steier, Peter and Sterba, Johannes H. and Golser, Robin},
Journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
Year = {2015},
Number = {0},
Pages = {--},
Abstract = {Abstract Neutron activation analysis using decay counting of the activated element is a well-established method in elemental analysis. However, for chlorine there is a better alternative to measuring decay of the short-lived activation product chlorine-38 (t1/2 = 37.24 min) – accelerator mass spectrometry (AMS) of 36Cl: the relatively high neutron capture cross section of chlorine-35 for thermal neutrons (43.7 b) and combined the AMS technique for chlorine-36 (t1/2 = 301 ka) allow for determination of chlorine down to ppb-levels using practical sample sizes and common exposure durations. The combination of neutron activation and AMS can be employed for a few other elements (nitrogen, thorium, and uranium) as well.},
Doi = {10.1016/j.nimb.2015.06.003},
File = {Winkler2015.pdf:Winkler2015.pdf:PDF},
ISSN = {0168-583X},
Keywords = {Trace elements, Chlorine, Nuclear Activation Analysis, Accelerator mass spectrometry, VERA},
Owner = {Johannes},
Spezifikation = {AA, inhouse},
Timestamp = {2015.06.22},
Url = {http://www.sciencedirect.com/science/article/pii/S0168583X15005406}
}
[2] G. Steinhauser, J. H. Sterba, K. Poljanc, M. Bichler, and K. Buchtela, “Neutron Activation Analysis of Sea-, Lake-, and evaporated Salt,” Czechoslovak journal of physics, vol. 56, p. D165–D175, 2006.
[Bibtex]
@Article{Steinhauser2006c,
Title = {{N}eutron {A}ctivation {A}nalysis of {S}ea-, {L}ake-, and evaporated {S}alt},
Author = {Steinhauser, G. and Sterba, J. H. and Poljanc, K. and Bichler, M. and Buchtela, K.},
Journal = {Czechoslovak Journal of Physics},
Year = {2006},
Pages = {D165--D175},
Volume = {56},
Abstract = {Salt is essential for human nutrition. Recently, it has become popular in Europe to rather use exotic sea salt or lake salt instead of purified evaporated salt, because of an alleged higher content of trace elements. In this study the content of trace elements and their bioavailability of 19 samples of different types of salt and 1 sample of brine purification sludge were investigated using instrumental neutron activation analysis. In general, sea-, lake-, and evaporated salt are quite pure. Trace elements determined in salt were Al, Br, Co, Cr, Cs, Fe, Rb, Sc, Sr, and Zn; some of them only in individual cases. It was found that, in general, the content of trace elements in sea- or lake salt was higher than in purified salt. Nevertheless, the use of sea- or lake salt does not contribute significantly to the human needs of essential trace elements, because their concentration in salt is too low or their compounds are not bioavailable.},
File = {Steinhauser2006c.pdf:Steinhauser2006c.pdf:PDF;Steinhauser2006c.pdf:Steinhauser2006c.pdf:PDF},
Spezifikation = {inhouse, AA, salz},
Timestamp = {2006.12.21}
}
[3] G. Steinhauser, J. H. Sterba, K. Poljanc, M. Bichler, and K. Buchtela, “Trace elements in rock salt and their bioavailability estimated from solubility in acid,” J. trace elem. med. bio., vol. 20, iss. 3, p. 143–153, 2006.
[Bibtex]
@Article{Steinhauser2006b,
Title = {{T}race elements in rock salt and their bioavailability estimated from solubility in acid},
Author = {Steinhauser, Georg and Sterba, Johannes H. and Poljanc, Karin and Bichler, Max and Buchtela, Karl},
Journal = {J. Trace Elem. Med. Bio.},
Year = {2006},
Month = sep,
Number = {3},
Pages = {143--153},
Volume = {20},
Abstract = {In this study, 18 partly commercially available samples of rock salt from Austria, Germany, Pakistan, Poland, Switzerland, and Ukraine were investigated with respect to their content of trace elements using instrumental neutron activation analysis. Elements detected were Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, La, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, and Zn, some of them only in individual cases.An estimation of the bioavailability of these trace elements was performed by dissolving an equivalent of the sodium chloride samples in diluted hydrochloric acid (simulating stomach acid), filtering off the insoluble components, and analyzing the evaporated filtrate. It could be shown that in most cases bioactive trace elements like Fe can be found in rock salt in the form of almost insoluble compounds and are therefore not significantly bioavailable, whereas thorium, for example, was partly bioavailable in two cases. A significant contribution to the recommended daily intake of metal trace elements by using rock salt for nutrition can be excluded.},
File = {Steinhauser2006b.pdf:Steinhauser2006b.pdf:PDF;Steinhauser2006b.pdf:Steinhauser2006b.pdf:PDF},
Keywords = {Rock salt, Nutrition, Neutron activation analysis, Sodium chloride, Bremsstrahlung spectrum},
Spezifikation = {salz, inhouse},
Timestamp = {2006.09.07},
Url = {http://www.sciencedirect.com/science/article/B7GJC-4KM46S0-1/2/0dca5f210b0696a7d0a3dc5988bc6520}
}

Write a Comment

Comment

*