Conclusions Initial investigation of the hair sample found that there is a greater amount of lipid content in the medulla while primarily protein exists in the cortex of the hair sample. Infrared spectra of the medulla green and cortex red.
An FTIR imaging system that is coupled with a linear array detector does not require a step-scan instrument but provides a fast and efficient analytical method to study various systems while collecting complete infrared Human hair profiling with ftir spectroscopy and chemometrics.
You may subscribe either as an OSA member, or as an authorized user of your institution. The current methodology of microscopic examination of potential hair evidence is absent of statistical measures of performance, and examiner results for identification can be subjective. Infrared imaging was able to identify the different components of a hair specimen and also provide information concerning distribution of the secondary structures of the proteins present in the hair sample.
There are a wide range of applications that have taken advantage of the attractive qualities of FTIR imaging systems including product development, biomedical research, forensics, polymers, and proteins.
From a forensic perspective, this technique would be complementary to microscopic hair examination, and in no way replace it. Complete infrared spectra with a spectral range from — cm-1 were collected.
The presence of various toxins and nutrient deficiencies or abundances can be determined using this process. As such, this methodology is able to provide a statistical measure of confidence to the identification of a sample of human, cat, and dog hair, which was called for in the National Academy of Sciences report.
Infrared microscopy is one tool that can be used to examine the interior of the hair and differentiate passive contamination from drugs absorbed into the hair from ingestion. Hair sample image with FTIR microscope. Citation lists with outbound citation links are available to subscribers only.
This model was successful in distinguishing between the three classes and, more importantly, all human samples were correctly predicted as human.
An instrument resolution of 16 cm-1 was used to collect 32 scans for the single-beam background and sample spectra. Numerous methods for collecting the imaging data exist, many of them requiring expensive step-scan instruments in combination with a focal plane array FPA detector that involves sophisticated electronics for reading the multiple detector elements.
An external validation resulted in zero false positive and false negative assignments for the human class. More importantly, this approach is non-destructive, rapid, can provide reliable results, and requires no sample preparation, making it of ample importance to the field of forensic science.
Here, attenuated total reflection ATR Fourier transform-infrared FT-IR spectroscopy was used to analyze synthetic fibers and natural hairs of human, cat, and dog origin.
Chemometric analysis was used to differentiate hair spectra from the three different species, and to predict unknown hairs to their proper species class, with a high degree of certainty. By slicing the hair specimen as either a cross section or laterally, infrared spectra can be obtained of the cortex and medulla of a single hair with a spatial resolution as high as 6.
When the spectral data is input into the Secondary Structure Estimation software, it is found that a higher amount of alpha helix is present in the cortex while there is more beta sheet found in the medulla portion. Hair analysis can provide vital information concerning important chemicals that may be in the body.
Cited by links are available to subscribers only. FTIR imaging is used to describe the collection of a chemical profile of the sample area by expressing the intensity of a single absorption peak, or ratio of two absorption peaks, using an image "map".A forensic investigation of single human hair fibres using FTIR-ATR spectroscopy and chemometrics Barton, Paul Matthew John () A forensic investigation of single human hair fibres using FTIR-ATR spectroscopy and chemometrics.
Forensic differentiation of human and animal hair via ATR FT-IR spectroscopy and chemometrics The difference between a human hair and an animal hair may not be obvious to the naked eye, until it is scrutinized underneath the.
Here, attenuated total reflection (ATR) Fourier transform-infrared (FT-IR) spectroscopy was used to analyze synthetic fibers and natural hairs of human, cat, and dog origin. Chemometric analysis was used to differentiate hair spectra from the three different species, and to predict unknown hairs to their proper species class, with a high degree.
Use of FTIR spectroscopy and chemometrics for the classification of carobs origin. The elemental profiling of carob fruits (wild and grafted) has also been studied.
Carbohydrates composition and classification (differentiation) by HPAEC-PAD and FTIR spectroscopy-chemometrics. J Food Compos Anal, 52 (). i A Forensic Investigation of Single Human Hair Fibres using FTIR-ATR Spectroscopy and Chemometrics A thesis submitted as partial fulfilment of the requirements.
Human-scalp hair samples were discriminated by Fourier transform infrared (FT-IR) micro-spectroscopy and chemometrics. The hairs were flattened with a small metallic roller, and the spectra were collected in the reflectance mode.Download