Radiochemical analysis of 93Zr.

The zirconium isotope 93Zr is a long-lived pure beta-particle-emitting radionuclide, which is produced by nuclear fission and neutron activation of the stable isotope 92Zr. This element is a constituent of the structural components of nuclear reactor vessels. A selective liquid-liquid extraction method for radiochemical separation of Zr, based on liquid-liquid extraction with 1-(2'-thenoyl)-3,3,3-trifluoroacetone in xylene and a subsequent stripping of 93Zr by an aqueous acid solution, has been developed. The method was utilised to separate Zr from other pure beta-particle and beta-gamma emitters in different kinds of samples. Decontamination factors higher than 99% for the pure beta-particle and beta-gamma emitters and an overall chemical yield of 80% were obtained. The sensitivity of the method allows the determination of the isolated 93Zr by liquid scintillation counting and the minimum detectable activity value obtained was 0.067 Bq over a counting period of 60 min.

Radiochemical analysis of 41Ca and 45Ca.

The radioactive isotopes of calcium, 41Ca (t1/2 = 1.03 x 10(5) yr) and 45Ca (t1/2 = 163 d), are produced by neutron capture in the stable isotopes 40Ca and 44Ca, respectively. These radionuclides are present in the environment due to the reactions between the galactic cosmic rays and the earth's surface, and in nuclear power plants by the activation of the structural components of nuclear reactor vessels. The aim of this paper is to propose a radiochemical separation method of 41Ca and 45Ca from the other beta gamma emitters present in radioactive materials, based on selective precipitation reactions. The activities were measured by liquid scintillation counting (LSC). The obtained decontamination factors are satisfactory for each radioactive component of the initial sample in that their activities in the final product were lower than the minimum detectable activity (MDA) due to the effectiveness of the radiochemical procedure. The sensitivity of the method allows the radiological characterization of 41Ca and 45Ca content in radioactive materials.

Direct determination of prolintane and its metabolite oxoprolintane in human urine by capillary zone electrophoresis and beta-cyclodextrin-modified micellar electrokinetic chromatography.

This paper describes a fast and simple method for the direct determination of the stimulant prolintane and its principal urinary metabolite, oxoprolintane, in human urine by capillary zone electrophoresis and beta-cyclodextrin-modified micellar electrokinetic chromatography. The determination was performed in phosphate buffer, pH 8.5, with UV detection at 211 nm. The effect of the ionic strength ratio between sample and running electrolyte, pH, sodium dodecyl sulphate and beta-cyclodextrin concentrations, and other factors, on the electrophoretic signals of these drugs was examined. This method can be applied for doping control. The determination limits are 1.0 microgram ml-1 for prolintane and 0.7 microgram ml-1 for oxoprolintane.