success is not guaranteed[]. DNA analysis is extremely costly and time consuming, not to mention that most laboratories are currently backlogged. A method for determining the identity of an unknown fiber quickly, with a high degree of certainty, and eliminating examiner bias would be extremely useful and cost-effective for the field of forensic science. ATR FTIR spectroscopy is a technique rising in popularity for analytical and biological purposes. It has been employed for the analysis of biomedical samples[], paint[, ], fingerprints[] and ink[]. The attributes of ATR FTIR spectroscopy are very attractive for forensics because of its rapid and non-destructive nature, its ease-of-use and minimal to no sample preparation. An infrared spectrum displays the vibrational characteristics of a sample based on the different absorption frequencies of the individual functional groups[]. The ATR attachment allows for analysis of solid samples, often with no sample preparation[]. The advantage of combining ATR FTIR spectroscopy with chemometrics is its ability to enhance the selectivity of the instrument and create classification models[, , ]. Two published studies demonstrate the use of FTIR and chemometrics to differentiate the spectra from different types of hair. Espinoza et al. applied infrared spectroscopy and advanced statistics to the forensic identification of elephant and giraffe hair[]. They visually observed a difference in the elephant and giraffe hair spectra at a very prominent peak (1032 cm-1), which is due to surface cystine oxides and the presence of cysteic acid. Through the discriminant analysis of their spectral data they demonstrated a performance index of 91.8%, which specifies how well their algorithm can differentiate between elephant and giraffe hair. Another group combined FTIR microscopy and chemometrics to differentiate Asian hair samples and black Caucasian hairs[]. Using Principle Component Analysis (PCA), they were able to separate the three female Asian hair samples from the three female Caucasian hair samples demonstrating their ability to discriminate between hair from two different races.
success is not guaranteed[]. DNA analysis is extremely costly and time consuming, not to mention that most laboratories are currently backlogged. A method for determining the identity of an unknown fiber quickly, with a high degree of certainty, and eliminating examiner bias would be extremely useful and cost-effective for the field of forensic science. ATR FTIR spectroscopy is a technique rising in popularity for analytical and biological purposes. It has been employed for the analysis of biomedical samples[], paint[, ], fingerprints[] and ink[]. The attributes of ATR FTIR spectroscopy are very attractive for forensics because of its rapid and non-destructive nature, its ease-of-use and minimal to no sample preparation. An infrared spectrum displays the vibrational characteristics of a sample based on the different absorption frequencies of the individual functional groups[]. The ATR attachment allows for analysis of solid samples, often with no sample preparation[]. The advantage of combining ATR FTIR spectroscopy with chemometrics is its ability to enhance the selectivity of the instrument and create classification models[, , ]. Two published studies demonstrate the use of FTIR and chemometrics to differentiate the spectra from different types of hair. Espinoza et al. applied infrared spectroscopy and advanced statistics to the forensic identification of elephant and giraffe hair[]. They visually observed a difference in the elephant and giraffe hair spectra at a very prominent peak (1032 cm-1), which is due to surface cystine oxides and the presence of cysteic acid. Through the discriminant analysis of their spectral data they demonstrated a performance index of 91.8%, which specifies how well their algorithm can differentiate between elephant and giraffe hair. Another group combined FTIR microscopy and chemometrics to differentiate Asian hair samples and black Caucasian hairs[]. Using Principle Component Analysis (PCA), they were able to separate the three female Asian hair samples from the three female Caucasian hair samples demonstrating their ability to discriminate between hair from two different races.