Magnesium interference in the determination of sodium in biological material by neutron activation analysis

Irradiation of MgSO₄ in a neutron flux with a thermal neutrons to fast neutrons ratio of $\text{12.1}\text{1}$ resulted in the production of 0.65 μg of Na per mg of Mg. Using this constant and the Mg content of the peanut sample the Mg contribution to the observed Na was estimated. Such estimates revealed that in some peanut tissues Mg contribution accounted for as much as 42% of the total observed Na.     

Charged-particle activation analysis of biological material

Charged-particle activation analysis offers a number of interesting possibilities for the determination of trace elements in biological material. It allows the determination of those elements that are difficult or impossible to determine by neutron activation, such as Li, B, Al, Si, V, Cr, Ni, Cd, Sn, Tl, and Pb. Up to now, protons have been successfully applied to samples of both vegetale and human origin. A number of difficulties have to be overcome, one of which is excessive heating of the samples owing to the limited range of the charged particles, thus giving rise to a high energy deposition in a small volume. Moreover, the sample composition has to be known to allow the calculation of the range of the particles. an interesting alternative has been proposed using an internal standard together with a standard additions procedure. Proton activation analysis was tested on a wide variety of reference materials, giving evidence that accurate results can be obtained for many trace elements, even when applying a purely instrumental method. Thus, the method can also be applied in the certification of reference materials, since nuclear methods are independent of chemical properties of the sample.     

Neutron activation analysis for the determination of trace elements in biological materials

Biological Trace Element Research - Neutron activation analysis, in both its radiochemical and instrumental forms, is a precious technique for the determination of trace elements in biological...     

Vanadium determination at the ultra-trace level in biological reference materials and serum by radiochemical neutron activation analysis

In order to help resolve present inconsistencies of two orders of magnitude or more in reported levels of vanadium in human serum and blood, a totally postirradiation radiochemical neutron activation analysis (NAA) method was further developed and applied to some pertinent nanogram and subnanogram reference materials. In particular, the second generation human serum reference material of Versieck was found to contain a value of 0.67±0.05 ng/g dry wt., corresponding to 0.061±0.005/4/ (see Table 1) ng/mL original fresh serum. Results are also reported for some other appropriate CRMs. Additionally, a small-scale study in 10 normal subjects (5 m, 5 f) revealed levels similar to those in the serum reference material and in agreement with the lowest data reported in the literature. Discussion of pitfalls of vanadium determination and the use of reference materials is included.     

Aspects of accuracy and precision in the determination of As and Sb in biological materials by neutron activation analysis

Biological Trace Element Research - Aspects of accuracy and precision of the determination of As and Sb in biological materials, using neutron activation with hydride generation, are discussed. It...     

A sensitive assay for the determination of propionyl-CoA in biological material

A method has been developed for the determination of low amounts of propionyl-CoA in biological material. The method involves ¹⁴CO₂ fixation by propionyl-CoA in the presence of purified propionyl-CoA carboxylase. Values for propionyl-CoA in rat liver in vivo and in isolated rat livers perfused in the presence of propionate are reported.