Preliminary results on a new method for producing yttrium phosphorous microspheres.

This paper reports on a new method to embed phosphorus particles into the matrix of yttrium aluminum silicate microspheres. Yttrium phosphorus glass microspheres about 20µm in size were obtained when an aqueous solution of YCl3 and AlCl3 were added to tetraethyl orthosilicate (TEOS) (phosphoric acid was used to catalyze the hydrolysis and condensation of TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by this method are regular and nearly spheric in shape. Paper chromatography was used to determine the radiochemical impurity of radioactive microspheres. Radionuclide purity was determined using a gamma spectrometry system and an ultra-low level liquid scintillation spectrometer. The P(+) ions implantation stage was eliminated by embedding phosphorus particles in the matrix of the glass microspheres. This paper shows that a high temperature is not required to produce yttrium phosphorus aluminum silicate microspheres. The result shows that the silicone oil spheroidization method is a very suitable way to produce yttrium phosphorus glass microspheres. The topographical analysis of microspheres shows that the Y, P, Si, and Al elements are distributed in the microspheres and the distribution of elements in the samples is homogenous.

Production and quality control of radioactive yttrium microspheres for medical applications.

In this paper, a method for production of yttrium silicate microspheres is reported. Yttrium silicate microspheres with approximate sizes of 20-50µm were obtained when an aqueous solution of Y(NO3)3 was added to tetraethyl orthosilicate (TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by the proposed method were regular and nearly spherical. The spherical shapes, composition and element distribution were investigated by scanning electron microscopy (SEM), carbon/sulfur analysis and SEM/EDS mapping analysis. Paper chromatography was used to identify radiochemical impurities in the radioactive microspheres. The radionuclide purity was determined using a gamma spectrometry system and an ultra-low-level liquid scintillation spectrometer. The results indicated that the proposed silicone oil spheroidization method is suitable for the production of yttrium silicate microspheres.

[Accumulation of magnetic nanoparticles in plants grown on soils of Apsheron peninsula].

The disclosure of magnetic nanoparticles in five plant species growing in Apsheron peninsula have been detected by the EPR method. The EPR spectra of these nanoparticles proved to be similar to those of synthesized magnetic nanoparticles. The result demonstrated that plants are capable of absorbing magnetic nanoparticles from the soil. The accumulation of nanoparticles in plants is confirmed by the presence of a broad EPR signal whose maximum position of the low-field component changes from g = 2.38 and halfwidth of the signal of 32 mT at room temperature to g = 2.71 and 50-55 mT at 80 K. The intensity of the broad EPR signal for plants grown in radioactively contaminated areas (170-220 mkR per h) was substantially lower compared with plants grown on clean soil. The parameters of the broad EPR signal and its dependence on the temperature of recording were identical with those for synthetic magnetic nanoparticles. The photosynthetic activity and changes in the genome of irradiated plants by the analysis of PCR products were studied.