| Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 103 === Textile fibers transferred during an activity can be used as physical evidence in
support of investigations or as evidence in court. For instance, an object left at a crime
scene by a suspect may have fiber evidence that can link a suspect to the crime scene or in
the very least provide investigative clues about the suspect’s environment.
Polyester fibers are most common fibers in the world; especially they are usually involved
in the forensic cases. There is little chemical composition distinction between polyester
fibers from different sources.
This is practically true for those composed of polyethylene terephthalate (PET).
Statistical and multivariate data analyses can be useful tools in the evaluation of
spectroscopic data. Principle component analysis (PCA) is the one of the widely used
types of multivariate data analyses, has been used for pattern recognition within sets of
Raman spectra. The purpose of this study was to demonstrate the potential and suggest a
protocol for PET fiber individualization for the use of principal component analysis (PCA)
in the forensic analysis of PET fibers, using Raman spectroscopic data. 48 Polyester fibers
were chosen to analyze in this study.
The absorbance values were calculated for the 10 wavenumbers which included 627
cm -1 , 699 cm -1 , 854 cm -1 , 995 cm -1 , 1110 cm -1 , 1174 cm -1 , 1285 cm -1 , 1452 cm -1 , 1611 cm -1 ,
1725 cm -1 . Systematic classification of PET fibers has been performed using the signs and
magnitudes of the PCA loading.
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