Related Experiment Video
Updated: Jan 1, 2026

Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications
Published on: February 23, 2017
Accuracy of Thermodynamic Databases for Hydroxyapatite Dissolution Constant.
Nita Sahai1,2,3, Martin A Schoonen4,5
1Department of Polymer Science, University of Akron, Akron, Ohio.
Discrepancies in calcium phosphate solubility data across databases can lead to errors in water speciation calculations. This study highlights significant variations in hydroxyapatite solubility, suggesting Thermo.dat offers a more reliable value.
Area of Science:
- Geochemistry
- Environmental Science
- Aqueous Chemistry
Background:
- Aqueous speciation calculations rely on solubility constant values from various databases.
- Discrepancies in these values, particularly for calcium phosphate minerals, can introduce significant errors in water chemistry modeling.
- Hydroxyapatite (HAP) solubility data exhibits substantial variability across different sources.
Purpose of the Study:
- To identify and highlight discrepancies in solubility constant values for calcium phosphate minerals used in common aqueous speciation software.
- To investigate the reasons behind the wide range of experimental solubility product determinations for hydroxyapatite.
- To evaluate the reliability of HAP solubility values in different databases.
Main Methods:
- Review and comparison of solubility constant values for calcium phosphate minerals from various databases.
- Analysis of experimental challenges affecting hydroxyapatite solubility determinations, including impurities, incongruent dissolution, and carbon dioxide contamination.
- Evaluation of the consistency of HAP solubility values with experimental data, considering potential experimental artifacts.
Main Results:
- Significant discrepancies, up to 10 orders of magnitude, exist in experimental hydroxyapatite solubility product values.
- Common experimental issues like impurities, incongruent dissolution, and CO2 contamination contribute to data variability.
- The solubility value for HAP in the Thermo.dat database is suggested to be more consistent with high-quality experimental data.
Conclusions:
- Inconsistent solubility data for calcium phosphate minerals can lead to erroneous water speciation calculations.
- The Thermo.dat database appears to provide a more accurate representation of hydroxyapatite solubility compared to other common databases.
- Careful consideration of experimental data quality and database selection is crucial for accurate geochemical modeling.
More Related Videos
13:46Separation of Single-stranded DNA, Double-stranded DNA and RNA from an Environmental Viral Community Using Hydroxyapatite Chromatography
Published on: September 29, 2011
13:00Hot Biological Catalysis: Isothermal Titration Calorimetry to Characterize Enzymatic Reactions
Published on: April 4, 2014
Related Concept Videos
Weak Acid Solutions
Solubility Equilibria
The...
Aqueous Solutions and Heats of Hydration
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
EDTA: Conditional Formation Constant
For the equilibrium reaction of the metal with the...
Constant Pressure Calorimetry
Thermodynamics: Activity Coefficient
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...