RMS Foundation
Bischmattstrasse 12
2544 Bettlach
Switzerland
Phone +41 32 644 2000
METHODS
Solubility product
Calcium phosphate ceramics are used, in part, as coatings on orthopedic implants. These materials are slowly absorbed in human tissue. In order to ensure the purity and consistency of calcium phosphate materials, it is advisable to determine the solubility product (KSP). The KSP is a material property that describes a chemical equilibrium between a solid substance and a solution of the same substance. The RMS Foundation offers a standardized procedure in which a sample is soaked in phosphoric acid for 60 days and the KSP is subsequently determined based on the pH value and the Ca and P concentrations
According to which standards do we test?
Whenever possible, we carry out our testing services in accordance with or based on these international standards:
- ISO 13779-6 (Annex A.8)
Which devices do we use?
- Temperature-controlled incubator shaker IKA™ KS 4000i
- Agilent 7700x ICP-MS
- pH electrodes
What you should know about this method?
Below are some questions you may have and which we will be happy to answer. If your question is not listed, please contact us and we will discuss your problem in a personal meeting.
What needs to be considered with these methods and samples?
We can test powders or coatings.
The minimum quantity is approx. 3 g
On request, we can also carry out parallel measurements on reference material (NIST).
Which products can be tested at the RMS?
The determination of the KSP is useful for monitoring the purity and consistency of hydroxyapatite raw materials on recurring production batches, or to compare the purity of the material with a hydroxyapatite NIST reference material. Further information can be found here.
Are the RMS analyses accredited?
Yes, the determination of the KSP of hydroxyapatite raw material powders according to ISO 13779-6 is validated and accredited.
New or customer-specific analysis methods can be validated by us.
Who is your contact person?
Christoph Stähli
PhD, MSc EPFL Mat. Sc.
Senior Scientist Bioceramics
+41 32 644 2044