Towards realistic measurements of bone mineral elemental composition through correlative spectroscopy

Ewerman, Josefin (author), Benedini Galli Zambardino, Fabiana (author), Leskovar, Tamara (author), Ben Amara, Heithem (author), Palmquist, Anders (author), Shah, Furqan A. (author)

Bone mineral is an ion-substituted carbonated apatite that is highly susceptible to lattice substitutions, and the commonly used Ca/P ratio does not adequately reflect this non-stoichiometric chemistry. We therefore propose cation-to-anion ratios (CARs) that account for major substitutions, including magnesium and sodium at calcium sites and carbonate at phosphate sites (B-type substitution). Bovine cortical bone slices were used as whole bone or after deproteinisation with 5% NaOCl for up to 168 h. B-type carbonate content determined by Raman spectroscopy and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) was used to correct phosphorus values measured by energy-dispersive X-ray spectroscopy (EDX). With progressive deproteinisation, Ca/P and Ca+Mg+Na/P increased significantly, revealing a substantial contribution of phosphorus from the organic matrix. Phosphorus correction by accounting for carbonate substitution generally lowered CAR values, showing that uncorrected CARs substantially overestimate bone mineral composition. These findings indicate that elemental ratios obtained directly from whole bone should be interpreted cautiously, while corrected CARs in deproteinised bone provide a more mineral-focussed basis for assessing bone mineral elemental composition.

• Language: English
• Keywords: Bones, Biomineralization, Raman spectroscopy, FTIR, EDX, Apatite
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FF - Faculty of Arts
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.01.2026
• Year: 2026
• Number of pages: Str. 1-4
• Numbering: Vol. 421, no. 141224
• PID: 20.500.12556/RUL-185205
• UDC: 902.3:6
• ISSN on article: 1873-4979
• DOI: 10.1016/j.matlet.2026.141224
• COBISS.SI-ID: 286202371
• Publication date in RUL: 28.07.2026

Record is a part of a journal

• Title: Materials letters
• Publisher: Elsevier Science
• ISSN: 1873-4979
• COBISS.SI-ID: 152132611

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: kosti, biomineralizacija, ramanska spektroskopija, FTIR, EDX, apatit