Human Hair Profiling with FTIR Spectroscopy and Chemometrics

homophile tomentum cerebri Profiling with FTIR spectrum analysis and ChemometricsProfiling of Human sensory cops exploitation FTIR Spectroscopy and Chemometrics TechniqueAUFA MADIHAH BT MOHAMAD ANWARResearch Proposal TopicProfiling of Human Hairs victimization FTIR Spectroscopy and Chemometrics Technique. This research is nigh classifying gentleman blurs-breadthcloth (subjects) using FTIR and Chemometrics. The subjects should be Malay, Woman and included in one of the age group required. (20-30, 31-40, 41-50, 60) gateBackground StudyHuman whisker is - keratin proteins and contains deoxyribonucleic acid which ar collected as physical evidence in a offence scene. It jakes provide important information in assisting an investigation. Usually, the evidence ( type) is obtained by physical contact between perpetrator with victim or/and perpetrator with surrounding or/and victim with surrounding. This theory is based on Locards Principle of Exchange which states that every contact leaves a hunt down.The received forensic procedures use comparisons of cop morphology by microscopic exam and mitochondrial DNA analyses. Microscopic examinations of the morphological characteristics of valet de chambre hairs indicate the thickness, color, shape, body line of business (e.g. scalp or pubic, axilla (chest, armpit and limb regions)), race and method of removal whether forcibly removed or earthyly fall off.In addition, there is not enough selective information on tender-hearted hair. thither had been a research in diverseiating compassionate hair according to the race. Thus, to construct additional data about sympathetic hair this research pull up stakes be conducted on different age group. The subjects for this research should be Malay, charr and is included in one of the age group required (20-30, 31-40, 41-50, 60). two hundred subjects leave be needed and 50 subjects per age group ar required.Hair sample will be taken from these 200 subjec ts and will be examine using FTIR- Fourier Transform Infr ared Spectroscopy method. The data obtained will be collapse using Chemometrics.3.0 Literature Reviews3.1 Human HairHair starts from its root embedded in the follicle, through the dermis, epidermis, stratum corneum, skin, into a shaft and stops at the tip end. Human hair is unremarkably 15-100 in diameter. in that location are three major of regions in pitying hair that are identifiable using FTIR-ATR ( inscribe 1). The core or medulla which is 5-10 in diameter is being wrapped by cortex which makes up the bulk of the hair. The outermost level of hair is know as scale which it thickness is less than 5. (Feughelman M.et al., 1997)Figure 1 Diagram of human beings hair cross section using ATR.3.1.1 shieldThe external forge of the grapheme which consists of flattened overlapping scales is cognise as cuticle (Figure 2). Cuticle stabilizes the hair.Figure 2 Schematic diagram of illustrating the morphological of a human hair fibreCuticle booth is separated by the cell membrane matrix (CMM) which is a strong adhesive layer. The CMM is made up of a central, polysaccharide -layer in between two -layers (lipid rich). Distinct layers, epicuticle, A-layer, exocuticle, and endocuticle end be found in a mature cuticle cell. The distinguishable layers have different levels of proteins, lipids and carbohydrates. Epicuticle is approximately 80% protein and 5% lipid and it is chemical substancely resistant. The A-layer resists physical and chemical forces and is cystine rich (30%). An illustration of the cross section of developed cuticle cell is shown in figure 3. (Jolles P. et al., 1997)Figure 3 A schematic diagram of the developed cuticle cross section.3.1.2 cerebral cortexCortex is covered and surrounded by cuticle. Cortex is responsible for the mechanical properties of the fiber. It is compose of elongated, spindle-shaped cortical cells packed closely that are parallel orient to the axis of the f iber. Cortical cells are typically 100m in length and 5m in width aligned on the axis of the fiber. It is made up by fine micro fibrils that are comprised of -helical proteins. Macrofibrils (approximately 100-400nm in diameter) is made up of grouped microfibrils which are 7nm in diameter. 60 % of the cortex (by mass) was made up by macrofibrils which were embedded in an uncrystallised protein matrix. (Jolles P. et al., 1997)3.1.3 MedullaMedulla is the inner part of the hair fiber. It is also known as core with a diameter of 5-10 m. The medulla whitethorn be completely absent or a double medulla may be observed. It has high lipid content (citrulline). The structure of medulla has a porous structure create by sponge-like keratin ad several(prenominal) vacuoles filled with air resulting from the differentiation process. The medulla was separated from cortex by CMM. (Jolles P. et al., 1997)3.2 Chemical Structure3.2.1 -Keratin ProteinsKeratin is a part of fibrous geomorphological pr oteins and is the important material making up the outer layer of human skin and it is also key structural component of hair and nails. In a single fiber, keratin constitutes about 85% of the mass. compressing of L-amino group acids formed polypeptide chains which were contained in high molecular weight polymer (keratin). Peptide bond (links the amino acid) was formed through the condensation. Multiple condensations will produce polypeptide chain which becomes the thorn of the -keratin fiber. The reaction was shown in Figure 4Figure 4 Condensation reactions of amino acids.The side chains (R1 and R2 group) of the amino acid residues for -keratin are corresponded to different age group. (Feughelman M.et al., 1997)3.3 rhetorical Hair as Physical Evidence3.3.1 What is rhetorical and Trace Evidence?Forensic was derived from Latin word forensic which is of or used in courts of law. It also denotes the application of scientific methods and techniques to the investigation of crime. For ensic involves trace evidence which stand also be specify as physical evidence of minute in the form fiber (textile, human or animal), soil, glass, fingerprints and tons other that needed to be consider under microscopic comparison. The presence and recovery of trace evidence is important to help in an investigation. DeForest states that trace evidence has an important reference to play in both the investigative and adjudicative human bodys of a chance. Locards Principle of Exchange stated that every contact leaves a trace is a fundamental theory on how trace evidence could hold out in the crime scene. (Fido M. et al., 2003)3.3.2 The Importance of Hair (Fiber) as EvidenceHair and fibre is important in providing valuable information in identifying the aggressor or attacker. The discovery of hair evidence can help in distinguish race and sex. Even though hair is benign suddenly matter it still contains DNA to be extrapolated. Human hair is usually found in the crime scene as shown in instrument panel 1. It can be naturally shed (normal hair-growth cycle) or forcibly remove. (Robbins C.R., 1994) carry over 1 Histogram of the relationship between the frequencies with different types of trace evidence occurs in criminal cases. (Broad J., 1988)3.4 Current Forensic Methods in Analyzing Hair Evidence3.4.1 macroscopic AnalysisThe hair evidence will first undergo visual examination followed by macroscopic examination of the hair morphology. The physical appearances (length, shape, root, tip, color, etcetera) are observed and measured. (Phillips J.H., 1989)3.4.2 Microscopy3.4.2.1 Optical Light Microscopy and StereomicroscopyStereomicroscope, compound blithe nigh/polarizing microscope, transmitted light comparison microscope and the laser confocal microscope are four types of microscopes used to examine the hair fiber (evidence). Through light microscope and stereomicroscope, racial origin, species and the somatic (body location) origin can be determined. Th e scanning laser confocal microscope is used to analyze the transverse cross-section(prenominal) which is important in determining the somatic origin or ethnicity. relation microscope is used for next step by comparing the evidence with known fibers from suspect. Conclusions are drawn from all these observations and analysis. (Ogle Jr. R. R. et al., 1999)3.4.2.2 scan Electron MicroscopyScanning Electron Microscopy can be used to analyze trace physical evidence (fibers, paints, glass and gunshot residues. SEM highlights the surface topography of the external cuticle layer in great detail with greater depth of field than a stereomicroscope. (Taylor et al., 1971) SEM is more preferable than Optical Light Microscopy. SEM can identify the species of the fiber evidence. It can differ human fiber from animals or wools or etc. But, SEM is difficult for comparison of human hairs because the variability in the surface topography, statistical distribution and appearance of the scales within one head are great, according to the natural and cosmetic history. Thus, SEM also lack in aiding the investigation involving human hair as evidence. (Kupferschmid T.D. et al., 1994)3.4.3 DNA AnalysisDNA (Deoxyribonucleic acid) is human genetic code which no one will have the same. DNA is in the cell nucleus and in extra-nuclear organelles of the cell, known as mitochondria. It is responsible in determining our physical characteristics. (Davis C.L., 1998) In hair, there are two root words of DNA traces that can be analyze for forensic purpose which can be found at follicular tissue and the cells on the hair root. The hair that was forcibly removed from head has its root habituated. However, most human fiber that found in the crime scene (ca. 90%) is in telogen phase (naturally shed) therefore the hair does not contain a growing root. There are three types of telogen hairroot without any soft tissues remainsroot with a small amount of soft tissue attachedroot with a large amount of soft tissue attachedHair roots that have soft tissues attached contain some cell with nucDNA. A study was conducted to investigate the nucDNA content in anagen versus telogen hair fibers. No nucDNA copies were detected in the shed hairs while the plucked hair contains an average 25,800 nucDNA.(Andreasson et al.,2006) In 2001, a series of single Short tandem bicycle Repeats (STR) typing steps and during consecutive polymerase chain reaction (PCR), DNA that had been extracted from the hair was fixed onto a membrane. (Hellman A. et al., 2001) In 2010, a proposal of a recent screening test to visualize DNA with 4-6-diamidino-2-phenylindole (DAPI) which is a fluorescent mite that binds on the double-stranded DNA, between A and T base pairs. The visible nuclear DNAs can be count with the use of a fluorescence microscope and it can readily discard hair that is less suitable for STR-typing. Thus, the attention was given to hair with highest potential for results. (Bourguignon et al., 2010)3.5 FTIR SpectroscopyFourier-transform Spectrometer is used in infrared submersion spectroscopy. Fourier-transform is a mathematical process. The term Fourier-transform infrared spectroscopy is originated from the fact that a Fourier transform is needed to convert the raw data into the actual spectrum. distributive spectrometer which measure intensity over a small throw of wavelengths at a time is different with FTIR spectrometer which simultaneously collects apparitional data in a large spectral range. Thus, FTIR is more preferable. Figure 5 show a diagram that represents Michelson interferometer. From a broadband source a radiation strikes the beam splitter. Some the light is transmitted to a stationary mirror and some of the light are reflected to a moveable mirror and the moving mirror is not in phase. A practice session called an interferogram which contains all the frequencies that make up the IR spectrum was produce by meddlesome constructively and destructively. T he interferogram can be decomposed into its component wavelengths which will resulted in a plot of intensity versus frequency. (Griffiths P.R. et al., 1986)Figure 5 Schematic diagram of the Michelson Interferometer.3.6 Chemometrics and Forensic ScienceChemometrics is the chemical discipline that uses statistical or mathematical methods to chemical data while forensic science is a discipline that formulates conclusions on a purely objective basis. It is compulsory for forensic scientist to follow stringent and rigid statistical protocols in reaching a conclusion regarding uninflected data. Thus, chemometrics is vital as it is capable in generating multidimensional data. By using chemometrics conclusions of research and analysis data can be obtained. (Bereton R.G., 2003)Chemometrics research can cover various areas of different methods and can be used in chemistry. There are methods forCollecting dataOptimization parameters of the parameterExperiments ruleCalibration and signal pro cessingGetting knowledge from the dataStatisticsStructure-property-relationship estimationsChemometrics helps in building a connection between the techniques and their application in chemistry. (Beebe K.R. et al., 1998)4.0 enigma StatementThese days when a crime occur it is hard to set the perpetrator due to lack of evidence. Although there is evidence but, there is no data that is available to describe the perpetrator. For an example, human fiber or hair can be found in crime scene. However without the data, the hair which is also evidence cant be identified. Furthermore, there is no research in finding whether there is difference in human hair of different age group. Moreover, can FTIR and chemometrics helps in profiling human hair research.ObjectivesThere are several aims or objectives that this research holdsTo throw out the investigation regarding human scalp hair (fibers) to create new database about human hair in different age group.To determined and sort out the differen ces of human scalp hair according to their respective age group.To analyze the FTIR data using Chemometrics.