Verifying measurements of residual calcium content in demineralised cortical bone
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Calcium contents of demineralised human cortical bone determined by titrimetric assay and atomic absorption spectrophotometry technique were verified by comparing to neutron activation analysis which has high recovery of more than 90%. Conversion factors determined from the comparison is necessary to correct the calcium content for each technique. Femurs from cadaveric donors were cut into cortical rings and demineralised in 0.5 M hydrochloric acid for varying immersion times. Initial calcium content in the cortical bone measured by titration was 4.57%, only 21% of the measurement by neutron activation analysis; while measured by atomic absorption spectrophotometer was 13.4%, only 61% of neutron activation analysis. By comparing more readings with the measurements by neutron activation analysis with 93% recovery, a conversion factor of 4.83 was verified and applied for the readings by titration and 1.45 for atomic absorption spectrophotometer in calculating the correct calcium contents. The residual calcium content started to reduce after the cortical bone was demineralised in hydrochloric acid for 8 h and reduced to 13% after 24 h. Using the linear relationship, the residual calcium content could be reduced to less than 8% after immersion in hydrochloric acid for 40 h. Atomic absorption spectrophotometry technique is the method of choice for calcium content determination as it is more reliable compared to titrimetric assay.
KeywordsAtomic absorption spectrophotometer Calcium content Cortical bone Demineralisation Neutron activation analysis Titrimetric assay
The study was supported by University of Malaya Research Grant (RG542-13HTM) and Bone Bank Internal Fund. The authors would like to thank Mr Hong Hao Chan for his technical assistance.
The study was supported by University of Malaya Research Grant (RG542-13HTM) and Bone Bank Internal Fund.
Compliance with ethical standards
Conflict of interest
All authors declared no competing of interest in the study.
- American Association of Tissue Banks (AATB) (2008) Standard for tissue banking, 12th edn. AATB, McLeanGoogle Scholar
- Dozza B, Lesci IG, Duchi S, Della Bella E, Martini L, Salamanna F, Falconi M, Cinotti S, Fini M, Lucarelli E, Donati D (2017) When size matters: differences in demineralised bone matrix particles affect collagen structures, mesenchymal stem cell behaviour, and osteogenic potential. J Biomed Mater Res, Part A 10(4):1019–1033CrossRefGoogle Scholar
- Hilmy N, Abbas B, Anas F (2007) Validation for processing and irradiation of freeze-dried bone grafts. In: Nather A, Yusof N, Hilmy N (eds) Radiation in Tissue banking: basic science and clinical applications of irradiated tissue allografts. World Scientific Publishing, Singapore, pp 219–234CrossRefGoogle Scholar
- Salim NAA, Hamzah MS, Elias MS, Siong WB, Rahman SA, Hashim A, Shukor SA (2013) Instrumental neutron activation analysis of marine sediment in-house reference material. J Nucl Relat Technol 10(1):1–7Google Scholar