METHODS AND OBJECTS OF CHEMICAL ANALYSIS ISSN title: "Metody i obʺekty himičeskogo analiza" An international journal devoted to all aspects of Analytical chemistry ISSN 2413-6166 (Online), ISSN 1991-0290 (Print)
		Ukr | En

Determination of cerium species in nanoscale calcium hydroxyapatite

A.O. Stoyanov, E.V. Khomenko I.V., N.P. Efryushina Stoyanova, N.A.Chivireva, V.P. Antonovich

Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine, Lyustdorfskaya dor. 86, Odessa, 65080 Ukraine

Results of the determination of cerium species in calcium hydroxyapatite samples Ca₁₀(PO₄)₆(OH)₂:Се activated by Ce(III) ions were presented. Samples were prepared by precipitation from water liquors and heated at different temperatures at air in reducing medium of carbon monoxide (II).
In this work luminescent spectroscopy, integral and derivative spectrophotometry were used. Dissolution of the samples was carried out in phosphoric acid, which in the decomposition of cerium-containing materials allows to keep the original species of cerium. To confirm obtained results considering the absence of appropriate reference materials quantitative determination cerium species in calcium hydroxyapatite samples activated by Ce(III) ions was carried by two spectrophotometric procedures: using integral and derivative absorption spectra of phosphate complexes Ce(III) and Ce(IV); and RedOx-reactions of inherent cerium species (spectrophotometric determination of Ce(III) by reduction of optical absorbance of the KMnO4; Ce(IV) – reduction of optical absorbance of the methanil yellow).
Significant influence of heat treatment conditions on the cerium species ratio was found.

Key words: cerium (III, IV), spectrophotometry, derivative spectrophotometry, hydroxyapatite

83-87