[en] Instrumental neutron activation analysis (INAA) techniques for filterable river water and suspended particulate matter (SPM) are described together with preconcentration techniques and simple radiochemical procedures to allow analyses when the trace element concentrations are very low (e.g. for mercury) and also when the sodium and calcium concentrations are very high. Detection limits are given for these methods and compared with those of other analytical techniques, including inductively coupled plasma emission spectrometry. The precision of measurement is between 10-15% for most elements and the detection limits are between 1 ng - 1 μg. (author)

[en] Soil samples from a waste water cleaning facility in Berlin, Germany, have been analyzed using several activation analysis methods. 43 elements have been determined by instrumental high energy photon activation analysis (PAA), instrumental thermal neutron activation analysis (NAA) and 14 MeV neutron activation analysis (fNAA). Conventional gamma-ray spectroscopy and low energy photon spectroscopy (LEPS) have been applied for product activity measurement. It has turned out that these methods in combination offer a wide spectrum of analytical information. (author)

[en] With the aim of indicating environmental pollution effects by heavy metals on humans using hair, nondestructive activation analysis was applied to 382 normal Japanese hair samples (background level). Elemental contents of hair could be determined for Ag, Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, I, K, La, Mg, Mn, Na, S, Sb, Sc, Se, Sm, Ti, V and Zn. As these elements in hair have wide concentration ranges, the differences in concentration distribution between groups (sex, age, permanent treatment and regional difference) are discussed. A method for hair sampling is presented. (author)

[en] The effect of temperature on the extraction of Co²⁺, Zn²⁺, Cd¹⁺ and Hg²⁺ by salicylaldoxime diluted with carbon tetrachloride was investigated radiometrically. It is found that the extraction constants at 25 deg C increase linearly with 1/r, where r is the effective coordination radius of the metal cation. The thermodynamic data calculated from the effect of temperature on the extraction showed that, 1) the extraction process is endothermic, 2) the dehydration of the metal cation in the extraction process is the predominating factor in determining the enthalpy variation and 3) the entropy variation is a contribution of the degree of order caused by the hydration of the proton and the highly ordered chelate structure of the extracted species. (author)

[en] Uranium and thorium in large scale integration (LSI) materials were determined by INAA. α-particles were also measured in these materials. The contents of uranium and thorium and the α-activity in ceramics and zirconia samples were very high. Calculation of α-flux from uranium and thorium contents and analysis of α-spectra were carried out for the ceramics and zirconia samples. The calculated values of α-flux in these samples agreed with the α-flux measured. (author)

[en] The solubility and solubility product of europium trifluoride were measured by radiometric, potentiometric and conductometric methods. There are significant differences in the values of both solubility and solubility product obtained by the three different techniques. Due to reasons discussed on the text, radiometric values seem to be more acceptable than the others. The thermodynamic functions such as ΔH⁰, ΔG⁰ and ΔS⁰ for the dissolution process were also measured. The positive values of ΔH⁰ and ΔG⁰ and the negative value of ΔS⁰ are indicative of the slight solubility of EuF₃. The dependence of solubility on pH and also on the fluoride concentration has also been studied. It was confirmed that europium forms a monofluoride in aqueous solution. The stability constant of this complex was estimated. (author)

[en] The possibility to use the most intensive gamma-peak of ²³⁹Np for INAA of uranium with epithermal neutrons and high resolution Ge(Li)-spectrometry is evaluated. A way for calculation of the peak area of overlapping peaks of ¹⁵³Sm and ²³⁹Np is proposed. This can be used in other similar cases in the practice of NAA. On this basis a scheme for NAA of uranium in geological objects is proposed. The lower detection limit is 8x10^-8 g U and the precision is 5-10% (relative standard deviation). The accuracy is demonstrated by the analysis of some geological standard reference materials. (author)

[en] Cherenkov photometry can be used for measuring coloured solutions. The use of Cherenkov photometry is very advantageous, because Beer's law is true in a very wide concentration interval. It was studied how the various isotopes and the external standard can be used for Cherenkov Photometry with Cr₂O₇^2- and CrO₄^2- in the 2-200 μg/cm³ interval. The upper measuring limits were found to be the lowest with low β energy isotopes. From among the isotopes studied the one with the highest energy can be used in the widest concentration interval. (author)

[en] Radiometric techniques for the determination of the nickel content in lateritic ore samples are described. In some of the methods proposed a semiconductor detector and a multichannel pulse height analyzer are required. In another technique a simple portable equipment with a proportional counter was used. Calculation methods of correction for matrix effects were applied, in combination with measurements of the fluorescence to scatter ratio and the use of edge filters. (author)

[en] Measurements on daughter radionuclides of parent-daughter relations can be used in routine instrumental neutron activation analysis if appropriate corrections for differences in irradiation, decay and counting time are applied. These corrections and their precision are discussed. (author)