de Jjm Jeroen Goeij

Magnesium transport between carp and water studied with 28Mg2+ as radiotracer

Abstract Neutron activation analysis and 28Mg2+ as radiotracer were used to measure magnesium distribution in fish and magnesium flows between carp and water. A novel tracer kinetic approach was applied to determine magnesium flows “to fish from water” (F ƒw ) and “to water from plasma (fish)” (Fwp). This revealed that F ƒw wp and thus pointing to another magnesium source than water, namely food.

Multi-element analysis of biological material by RNAA using HPLC with on-line yield determination

The idea to use high performance liquid chromatography with continuous UV detection for multi-element radiochemical separation and simultaneous multi-element “on-line” yield determination is introduced. The validity of the concept was evaluated by demonstrating the constancy of the ratio of the signals for a main isotope (60Co) and a carrier (59Co) as a function of the elemental mass processed in the separation. The suitability of the method for practical purposes is demonstrated by its application to the RNAA determination of cobalt in biological materials. It is concluded that the method, although not yet completely developed, bears the potential of improving both accuracy and precision of multi-element RNAA.

Co(III)EDTA as extra-cellular marker in μPIXE-analysis of rat cardiomyocytes

In previous studies no clear difference was found between the intra- and extra-cellular compartment in nuclear microprobe elemental distribution maps of freeze-dried cryo sections of heart tissue. Probably due to artefacts during the preparation of these samples, the intra-cellular and the extra-cellular content of elements are mixed up. In this article a method, using NaCo(III)EDTA as an extra-cellular marker, was applied to deconvolute the total ion content in an extra- and intra-cellular contribution. This method was both applied to normoxic heart tissue and low-flow ischemic heart tissue. Intra-cellular ion concentrations calculated from the corrected ion contents of the normoxic tissue agrees well with literature values. Moreover a clear elevation of the intra-cellular sodium and chlorine concentration was found in low-flow ischemic tissue.

Position of RNAA in trace-element analysis

An overview is presented of the characteristic features of RNAA (radiochemical neutron activation analysis). Criteria are given for comparison of RNAA with other trace-element analytical techniques. Appropriate fields of application of RNAA are indicated as well as approaches to secure the future position of the technique. Finally, some trends for further development of chemical separations in RNAA are outlined.

Neutron activation analysis: trends in developments and applications

New developments in instrumentation for, and methodology of, Instrumental Neutron Activation Analysis (INAA) may lead to new niches for this method of elemental analysis. This paper describes the possibilities of advanced detectors, automated irradiation and counting stations, and very large sample analysis. An overview is given of some typical new fields of application.

Nuclear, physical and chemical aspects in cyclotron production of radionuclides

The cyclotron has developed into an indispensable machine for production of a variety of radionuclides. Several nuclear, physical and chemical aspects are treated, with emphasis on their interdependencies, which are illustrated with examples. Attention is also given to production of short-lived positron emitters. These are of increasing interest, not only for clinical investigations, but also for technological research. Finally, the cyclotron as a production machine is compared to the nuclear reactor.

Thorium determination in a liver autopsy sample via direct γ-spectrometry and neutron activation analysis

Thorium was determined in a liver autopsy sample from a person treated with Thorotrast ca. 40 y earlier. The decay products228Ac,224Ra,212Pb,212Bi, and208Tl from the232Th series were identified by direct γ-spectrometry. Instrumental neutron activation analysis yielded a value of ca 22 g thorium per kg dry liver material. The total radiation dose to the whole liver was estimated in the order of 16 Gy.

NUCLEAR ELEMENTAL ANALYSES WITH A CYCLOTRON ON BIOMEDICAL SAMPLES

The Eindhoven scanning proton microprobe enables the determination of the ion content of heart tissue on a sub-cellular scale. It is shown that intra-cellular elemental concentrations can be determined. Measurements are carried out for physiological and patho-physiological rat heart muscle tissue. Important alterations in Na and K concentrations are reported as measured with PIXE, RBS and NFS techniques employing a variable energy cyclotron (3–30 MeV). However, quantitative intra-cellular determinations are hampered by the presence of extra-cellular space (ECS). For this purpose, cobaltic ethylene-diamine-tetra-acetic-acid (Co(III)EDTA) was used as an exogenic ECS marker. The intra-cellular ion concentrations of normoxic tissue after correction for the ECS agree well with the literature values.