Preparation and Comprehensive Characterization of a Calcium Hydroxyapatite Reference Material

Area of Science:

• Materials Science
• Biomaterials Science
• Chemistry

Background:

• Calcium hydroxyapatite (Ca10(PO4)6(OH)2) is extensively utilized in various scientific disciplines.
• Understanding its precise properties is crucial for reliable experimental outcomes.

Purpose of the Study:

• To conduct a detailed physicochemical characterization of calcium hydroxyapatite (HA).
• To certify HA as a National Institute of Standards and Technology (NIST) standard reference material (SRM 2910).

Main Methods:

• Employing a suite of analytical techniques including chemical and thermal analyses, X-ray diffraction, infrared and Raman spectroscopies.
• Utilizing scanning and transmission electron microscopy, and the Brunauer, Emmett, and Teller (BET) surface-area method.

Main Results:

• Determined elemental composition (Ca2+, PO4 3-, OH-, HPO4 2-, H2O, CO3 2-, trace elements) and Ca/P molar ratio.
• Characterized crystal size, morphology, surface area, unit-cell parameters, crystallinity, and solubility.
• Confirmed high purity, homogeneity, and high crystallinity of the synthesized HA.

Conclusions:

• The characterized calcium hydroxyapatite meets the stringent requirements for a NIST standard reference material.
• This certified HA (SRM 2910) will serve as a reliable standard for future research and applications.