TY - JOUR
T1 - La ions in precipitated hydroxyapatites
AU - Mayer, I.
AU - Layani, J. D.
AU - Givan, A.
AU - Gaft, M.
AU - Blanc, Ph
PY - 1999/4/15
Y1 - 1999/4/15
N2 - Hydroxyapatites were synthesized by precipitation from an aqueous solution with La3+ (0-0.75%) and with carbonate (0-6.1%) at controlled pH 7.0. Uptake of La3+ was 90-95% complete. Relatively low Ca/P (1.54-1.63) ratios were attributed to nonstoichiometry. Carbonate in samples was identified by IR spectroscopy as B-type carbonate. Lattice parameters of the hexagonal apatite structure were not affected by the La3+ content. Noncarbonated samples heated to 800°C transform partially to β- Ca3(PO4)2. Thermogravimetric analysis showed release of 0.4 mol adsorbed and 1 mol crystalline water up to 400°C and decomposition of carbonate up to 900°C in the samples. Luminescence data obtained for Gd-containing hydroxyapatites prove that Gd3+ ions are not incorporated in the precipitated hydroxyapatite. These findings suggest that, in the La- containing samples, La3+ is surface adsorbed and not incorporated in hydroxyapatite.
AB - Hydroxyapatites were synthesized by precipitation from an aqueous solution with La3+ (0-0.75%) and with carbonate (0-6.1%) at controlled pH 7.0. Uptake of La3+ was 90-95% complete. Relatively low Ca/P (1.54-1.63) ratios were attributed to nonstoichiometry. Carbonate in samples was identified by IR spectroscopy as B-type carbonate. Lattice parameters of the hexagonal apatite structure were not affected by the La3+ content. Noncarbonated samples heated to 800°C transform partially to β- Ca3(PO4)2. Thermogravimetric analysis showed release of 0.4 mol adsorbed and 1 mol crystalline water up to 400°C and decomposition of carbonate up to 900°C in the samples. Luminescence data obtained for Gd-containing hydroxyapatites prove that Gd3+ ions are not incorporated in the precipitated hydroxyapatite. These findings suggest that, in the La- containing samples, La3+ is surface adsorbed and not incorporated in hydroxyapatite.
KW - Carbonated hydroxyapatite
KW - Lanthanum hydroxyapatite
KW - Luminescence of Gd- hydroxyapatite
UR - http://www.scopus.com/inward/record.url?scp=0032991731&partnerID=8YFLogxK
U2 - 10.1016/S0162-0134(99)00019-7
DO - 10.1016/S0162-0134(99)00019-7
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 10376345
AN - SCOPUS:0032991731
SN - 0162-0134
VL - 73
SP - 221
EP - 226
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
IS - 4
ER -