We explored the potential of using energy-dispersive X-ray analysis (EDX), a non-destructive technique, to assess elemental contents in dolphin bones. Specimens were deposited in museum collections, and prepared by different methodologies. Fifty eight Commerson's dolphins (Cephalorhynchus c. commersonii) chevron bones and 24 Franciscana dolphins (Pontoporia blainvillei) were analysed. The EDX allowed us to detect the following elements: Ca, P, Na, Mg, Fe, K, Zn, S, Cl and Al; and quantify their proportion (weight percent of element). Principal components analysis differentiates two groups according to the cleaning procedures applied, supporting that cleaning methods could influence the chemical integrity of bone. No significant age-dependent increase was found for elements analysed in species, and no significant differences were found between sex and physical maturity stages. Alternative assessment was made through atomic absorption spectrophotometry, providing quantitative information on the principal elements in bones (Ca, P, Mg, Na, Fe and Zn) and allowing comparisons with other studies. A standard protocol for bone cleaning and conditioning is needed to exclude any effect on the mineral integrity of calcified tissue. This would enable future comparative studies on the bone mineral matrix over time housed in natural history museums or other scientific collections. ARTICLE HISTORY

We prepared high porous γ-Al2O3 samples via a modified sol-gel method in which polyvinyl-alcohol (PVA) was incorporated to hydrolysis water before the formation of boehmite sol with two different PVA contents (44 and 174 wt%). We compared our results with those of other γ-Al2O3 samples also prepared via sol-gel with different procedures; a sample without additives (sample S) and samples with the same contents of PVA but added to the already synthesized boehmite sol (A-samples); the latter as standard for evaluation of our modified sol-gel method (B-samples).Samples were characterized by means of XRD, adsorption-desorption isotherms of nitrogen at 77K and DTA-TG, and also were investigated against thermal cycling at 600 °C.Pore volume, porosity, BET area, and pore distribution were determined. B-sample with 44 wt% PVA showed similar characteristics to those of A-samples, while an important increase of pore volume, porosity and BET area (50%) was observed for sample with 174% PVA. Pore diameter of B-samples also exhibited a different behaviour with PVA content: addition of 44 wt% of PVA gave a 16% increase while 174 wt% PVA, 42%. These results indicated that adding PVA to the already sinthesized boehmite sol, mainly stabilizes the boehmite structure, without affecting it. On the contrary, incorporation of PVA before hydrolysis influences the particle size in the sol, greatly modifying the final boehmite network and giving place to larger pores in the final γ-Al2O3, this effect being significant when adding 174 wt% PVA.Results of thermal treatments at 600°C showed a decrease in BET area of all samples up to 80h, then stabilised. A minimal effect of the thermal treatments on the pore volume and porosity was observed in all samples while the pore diameter increased, this increase being most important in case of sample with 174 wt% PVA.

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