This paper deals with the structure of spherical particles in the micrometer range containing concentrated solutions of ceramic precursors. An appropriate cell has been developed for measuring in situ XAS spectra of aerosols. With this device, we have analysed a concentrated precursor solution of zirconia powder. Comparing spectra of zirconium nitrate nebulized solutions with that of hydrated zirconyl nitrate and monoclinic zirconia (ZrO2) clearly shows important differences in the coordination shells of the zirconium atoms related to modifications of the precursor during its transformation towards the oxide formation. On the other hand substantial alteration of the x-ray absorption spectrum of soluted salts with respect to the crystallized products is evidenced.