In:
Soil Science Society of America Journal, Wiley, Vol. 66, No. 2 ( 2002-03), p. 455-463
Abstract:
The incorporation of micronutrients into synthetic hydroxyapatite (SHA) is proposed for slow release of these nutrients to crops in the National Aeronautics and Space Administration's (NASA's) Advanced Life Support (ALS) program for Lunar or Martian outposts. Solid state 31 P nuclear magnetic resonance (NMR) was utilized to examine the paramagnetic effects of Fe 3+ , Mn 2+ , and Cu 2+ to determine if they were incorporated into the SHA structure. Separate Fe 3+ , Mn 2+ , and Cu 2+ containing SHA materials along with a transition metal free SHA (pure‐SHA) were synthesized using a precipitation method. The proximity ( 〈 1 nm) of the transition metals to the 31 P nuclei of SHA were apparent when comparing the integrated 31 P signal intensities of the pure‐SHA (87 arbitrary units g −1 ) with the Fe‐, Mn‐, and Cu‐SHA materials (37–71 arbitrary units g −1 ). The lower integrated 31 P signal intensities of the Fe‐, Mn‐, and Cu‐SHA materials relative to the pure‐SHA suggested that Fe 3+ , Mn 2+ , and Cu 2+ were incorporated in the SHA structure. Further support for Fe 3+ , Mn 2+ , and Cu 2+ incorporation was demonstrated by the reduced spin‐lattice relaxation constants of the Fe‐, Mn‐, and Cu‐SHA materials relative to pure‐SHA Inversion recovery spectra indicated that Fe 3+ , Mn 2+ , and Cu 2+ were not homogeneously distributed about the 31 P nuclei in the SHA structure. Extraction with diethylene‐triamine‐penta‐acetic acid (DTPA) suggested that between 50 and 80% of the total starting metal concentrations were incorporated in the SHA structure. Iron‐, Mn‐, and Cu‐containing SHA are potential slow release sources of Fe, Mn, and Cu in the ALS cropping system.
Type of Medium:
Online Resource
ISSN:
0361-5995
,
1435-0661
DOI:
10.2136/sssaj2002.4550
Language:
English
Publisher:
Wiley
Publication Date:
2002
detail.hit.zdb_id:
241415-6
detail.hit.zdb_id:
2239747-4
detail.hit.zdb_id:
196788-5
detail.hit.zdb_id:
1481691-X
SSG:
13
SSG:
21
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