title: Advantages of TOF-SIMS analysis of hydroxyapatite and fluorapatite in comparison with XRD, HR-TEM and FT-IR.
abstract: The chemical analysis of hydroxyapatite and fluorapatite was carried out using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Hydroxyapatite and fluorapatite were synthesized at 80 +/- 1 degrees C and pH 7.4 +/- 0.2. Fluorapatite was better crystallized, with its (300) reflection shifted to a slightly higher angle. High-resolution transmission electron microscopy clearly revealed a typical, regular hexagonal cross section perpendicular to the c-axis for fluorapatite and a flattened hexagonal cross section for hydroxyapatite. FT-IR spectra of fluorapatite confirmed the absence of OH absorption peak--which was seen in hydroxyapatite at about 3570 cm(-1). TOF-SIMS mass spectra showed a peak at 40 amu due to calcium. In addition, a peak at 19 amu due to fluorine could be clearly seen, although the intensities of PO, PO2, and PO3 were very low. It was confirmed that TOF-SIMS clearly showed the differences between positive and negative mass spectra of hydroxyapatite and fluorapatite, especially for F-. We concluded that TOF-SIMS exhibited distinct advantages compared with other methods of analysis.
authors.affiliation: Department of Biomaterials Science, Graduate School of Biomedical Sciences, Hiroshima University, Minami-ku, Japan. okazakix@hiroshima-u.ac.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Okazaki
authors.forename: Isao
authors.initials: I
authors.lastname: Hirata
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Junzo
authors.initials: J
authors.lastname: Takahashi
mesh_terms: D001031:Apatites / Q000737:chemistry*; D002118:Calcium / Q000032:analysis; D018360:Crystallography, X-Ray; D017886:Durapatite / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis; D046529:Microscopy, Electron, Transmission; D010710:Phosphates / Q000032:analysis; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001031:Apatites; D010710:Phosphates; D017886:Durapatite; C025105:fluorapatite; D005459:Fluorides; D002118:Calcium