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Iron, Manganese and Copper Release from Synthetic HydroxyapatiteKinetic stir-flow dissolution experiments were performed on iron- (Fe-SHA), manganese- (Mn-SHA), and copper- (Cu-SHA) containing synthetic hydroxyapatites. Solution treatments consisted of de-ionized water, citric acid and DTPA. Initially, Mn concentrations were higher than Cu concentrations and Fe concentrations were the lowest in all treatments. At later times Mn and Cu concentrations dropped in the DTPA treatment while Fe rose to the concentration similar to Mn and Cu. At all times, metal release concentrations in the water and citric acid treatments followed the trend of Mn>Cu>Fe. Rietveld analysis of x-ray diffraction data and ^31P NMR indicated that the metals substituted for Ca in the SHA structure. However, EPR data suggested that a metal (hydr)oxide phase existed either on the SHA surface or between the SHA crystallites. The metal concentration trend of Mn>Cu>Fe suggested that the initial solution metal concentrations are dependent on the dissolution of (hydr)oxides from SHA surfaces or between SHA crystallites. Similar metal concentrations at later times in the DTPA experiments suggests that metal concentrations were controlled by the release of Mn, Cu, or Fe from the SHA structure.
Document ID
20000084335
Acquisition Source
Johnson Space Center
Document Type
Preprint (Draft being sent to journal)
Authors
Sutter, B.
(Texas A&M Univ. TX United States)
Hossner, L. R.
(Texas A&M Univ. TX United States)
Ming, Douglas W.
(NASA Johnson Space Center Houston, TX United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1999
Subject Category
Geophysics
Meeting Information
Meeting: Science Serving Agriculture and Natural Resources: Past/Present
Location: Salt Lake City, UT
Country: United States
Start Date: October 30, 1999
End Date: November 4, 1999
Sponsors: American Society of Agronomy
Funding Number(s)
PROJECT: RTOP 131-50-20-23
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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