A rapid method has been developed for the determination of thallium in mineral samples by substoichiometric radiochemical analysis. The method is based on the extraction of thallium with substoichiometric amouts of potassium ethyl xanthate into chloroform from pH 10 in ammonia buffer.The effect of foreign ions on the extraction was studied. Thallium contents of sphalerite and galena ores were determined.
A rapid radiochemical method has been designed for the determination of microgram quantities of zinc, based on the substoichiometric isotope dilution, using potassium ethyl xanthate as the extraction reagent, pH5.5 in acetate buffers and chloroform as the extractant were found to be suitable for quantitative substoichiometric extraction. The influence of the diverse ions on the extraction was studied. The zinc contents of a medicinal preparation and biological samples were determined by the present method.
Concentration of137Cs, 134Cs and potassium were measured in several higher fungi and in substrates, soils, woods and litters in some Kanto and the Koshin districts, Japan, following the Chernobyl accident during October to November 1989. 137Cs concentrations in fungi were in the range of 0.7-101 Bq kg-1⋅fresh. Maximum137Cs level in them was observed in Boletopsis leucomelas (Pers.: Fr.) Fayod. Significantly higher levels of concentration ratios of137Cs in fungi to substrates (e.g.; 137Cs concentration · fresh in fungus/137Cs concentration · dry in soil), 10-1to10×10-1, were found nearly 10 to 1000 times as much as leaf vegetables, root crops and potatoes to substrates. It was confirmed that levels of concentration ratios of potassium were similar to those of137Cs. In all fungi, 134Cs which released from the Chernobyl accident and is not present in nuclear weapons fallout was not detected.
Volume reduction (N), tritium retention factor (R), tritium concentration factor (Z) and apparent separation factor (β) were measured on the large and small electrolytic cell systems. The relative variation of R was smaller than that of Z. So, it is recommended to use R in calculation of tritium concentrations in water samples. Furthermore, it was empirically revealed that R can be obtained only from N if a reliable β-value is previously known. Therefore, it is possible to obtain R without electrolysis of the tritium standard solution. Taking into account the above facts, the so-called non-spike analysis of tritium, in which electrolytic enrichment and liquid scintillation counting are combined, becomes practicable.
Blood volume (V), blood flow (F) and glomerular filtration rate (GFR) per 100 g (100 ml) of kidney were calculated with C15O, H215O and68Ga-EDTA, to study age-related changes per unit tissue in 19 subjects using positron emission tomography. Age was negatively correlated with V, F and GFR. The agingrelated decrease in V was less marked than those in F and GFR. Analysis by regression formula induced that F, GFR for subjects in their 70 s are 76%, 46% and 55% for those in their 20 s, respectively.