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Publication Citation: Elemental and Molecular Imaging of Human Hair Using Secondary Ion Mass Spectrometry

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Author(s): John G. Gillen; S V. Roberson; C M. Ng; M Stranick;
Title: Elemental and Molecular Imaging of Human Hair Using Secondary Ion Mass Spectrometry
Published: April 01, 1999
Abstract: Secondary ion mass spectrometry (SIMS) is used to image the spatial distribution of elemental and molecular species on the surface and in cross-sections of doped human hair using a magnetic sector SIMS instrument operated as an ion microprobe. Analysis of electrically insulating, non-planar hair samples requires one of two different methods of charge compensation to be used depending on the polarity of the sputtered secondary ions. For detection of positive secondary ions, the hair is imaged using a {approximately} 0.5 υm diameter, 19.5 keV impact energy, O- microbeam with no auxiliary electron bombardment. For detection of negative secondary ions, a {approximately} 0.2 υm diameter, 14.5 keV impact energy Cs+ microbeam is used in conjunction with normal incidence, low energy electron bombardment. Both of these methods allow submicrometer spatial resolution elemental and molecular secondary ion images to be obtained from hair samples without metallic coating of the sample surface prior to analysis. Several examples are presented that reflect potential application areas for these analytical methods.
Citation: Scanning Microscopy
Volume: 21
Pages: pp. 173 - 181
Keywords: hair analysis;molecular imaging;secondary ion mass spectrometry
Research Areas: Nanotechnology, Chemistry