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STATISTICAL ANALYSIS OF VISIBLE ABSORPTION SPECTRA AND MASS SPECTRA OBTAINED FROM DYED TEXTILE FIBERS
| Title: | STATISTICAL ANALYSIS OF VISIBLE ABSORPTION SPECTRA AND MASS SPECTRA OBTAINED FROM DYED TEXTILE FIBERS. |
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| Name(s): |
White, Katie, Author Sigman, Michael, Committee Chair University of Central Florida, Degree Grantor |
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| Type of Resource: | text | |
| Date Issued: | 2010 | |
| Publisher: | University of Central Florida | |
| Language(s): | English | |
| Abstract/Description: | The National Academy of Sciences recently published a report which calls for improvements to the field of forensic science. Their report criticized many forensic disciplines for failure to establish rigorously-tested methods of comparison, and encouraged more research in these areas to establish limitations and assess error rates. This study applies chemometric and statistical methods to current and developing analytical techniques in fiber analysis. In addition to analysis of commercially available dyed textile fibers, two pairs of dyes are selected for custom fabric dyeing based on the similarities of their absorbance spectra and dye molecular structures. Visible absorption spectra for all fiber samples are collected using microspectrophotometry (MSP) and mass spectra are collected using electrospray ionization (ESI) mass spectrometry. Statistical calculations are performed using commercial software packages and software written in-house. Levels of Type I and Type II error are examined for fiber discrimination based on hypothesis testing of visible absorbance spectra profiles using a nonparametric permutation method. This work also explores evaluation of known and questioned fiber populations based on an assessment of statistical p-value distributions from questioned-known fiber comparisons with those of known fiber self-comparisons. Results from the hypothesis testing are compared with principal components analysis (PCA) and discriminant analysis (DA) of visible absorption spectra, as well as PCA and DA of ESI mass spectra. The sensitivity of a statistical approach will also be discussed in terms of how instrumental parameters and sampling methods may influence error rates. | |
| Identifier: | CFE0003454 (IID), ucf:48396 (fedora) | |
| Note(s): |
2010-12-01 M.S. Sciences, Department of Chemistry Masters This record was generated from author submitted information. |
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| Subject(s): |
forensic science fiber examination fiber dyes microspectrophotometry (MSP) visible absorption spectra electrospray ionization mass spectrometry (ESI-MS) mass spectra nonparametric statistics type I error type II error multivariate statistics principal components analysis (PCA) discriminant analysis (DA) |
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| Persistent Link to This Record: | http://purl.flvc.org/ucf/fd/CFE0003454 | |
| Restrictions on Access: | public 2010-11-01 | |
| Host Institution: | UCF |
