Forensic identification of elephant and giraffe hair artifacts using HATR FTIR spectroscopy and discriminant analysis
Publication Type: |
Journal Article |
Year of Publication: |
2008 |
Authors: |
E. O. Espinoza, B. W. Baker, T. D. Moores, D. Voin |
Publication/Journal: |
Endangered Species Research |
Keywords: |
elephant, forensic mammalogy, giraffe, hair identification, infrared spectroscopy, wildlife trade |
ISBN: |
1863-5407 1613-4796 |
Abstract:
We investigated the utility of horizontal-attenuated total-reflection Fourier transform infrared (HATR FTIR) spectroscopy for the analysis and identification of tail hair of reputed elephant and/or giraffe origin, commonly used to manufacture indigenous artifacts (e.g. bracelets, earrings, finger rings, etc.) in the wildlife trade. We describe a prominent peak at 1032 cm–1, seen extensively in proboscidean standards and absent in giraffe samples. This absorption appears to be related to surface cystine oxides and suggests that cysteic acid is one of the compounds useful for distinguishing elephant and giraffe hairs. While spectral libraries are helpful in determining the material class represented by suspected hair artifacts (i.e. keratin vs. plastic vs. botanical), mathematical post-processing of the spectra employing discriminant analysis provided a more useful statistical tool for differentiating elephant and giraffe hairs than relying on visual inspection of spectral peaks alone. A resulting performance index of 91.8% shows that HATR FTIR, combined with discriminant analysis, is a powerful, nondestructive, quantitative technique for distinguishing elephant and giraffe keratins often encountered in museum collections and the modern wildlife trade.