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A. Limbeck, C. Feldgitscher, G. Kickelbick:
"Determination of the rare earth elements La and Eu in hybrid materials";
Poster: European Symposium of Atomic Spectroscopy (ESAS08), Weimar, Germany; 2008-09-28 - 2008-10-01; in: "ESAS08 - Book of Abstracts", (2008), 70.

Hybrid materials containing lanthanide ions attracted much interest in the last few years due to the wide range of optical applications, such as tunable lasers, luminescence displays, amplifiers for optical communication and optical storage based on photochemical hole burning. The incorporation of lanthanide ions or nanoparticles into a flexible and chemically stable polymeric matrix decrease concentration quenching and agglomeration phenomena. The preparation of the nanoparticles follows a 2 step procedure: the infiltration of the hybrid polymers with salt solutions and the subsequent precipitation of the nanoparticles. A third hydrothermal step can be applied resulting in crystalline nanoparticles. For improvement of the individual synthesis steps as well as for characterization of the final products an accurate quantification of lanthanide levels in hybrid materials is required.
In this work a digestion procedure for the quantitative mineralization of hybrid materials is presented, which enables in combination with conventional ICP-AES analysis measurement of Eu and La in these solid matrices. The method is based on a preliminary treatment of the hybrid materials with methanol and sodium hydroxide leading to a degradation of the polymer matrix. In a second step the derived reaction products were completely mineralized using nitric acid and hydrogen peroxide. For method optimization was this decomposition step performed with different procedures - namely a microwave assisted technique, an open vessel treatment at 115°C and reaction at room temperature in closed PE bottles. Analysis of the prepared solutions was performed using a Spectroflame P optical emission spectrometer (Spectro, Germany). Results derived for different hybrid materials indicated only minor differences between the individual approaches, unexpectedly showed the simple digestion performed under ambient pressure and temperature conditions best results for all investigated samples.

hybrid materials, rare earth elements, ICP-AES