This document summarizes the use of Fourier transform infrared spectroscopy (FTIR) to analyze hair samples for forensic purposes. It discusses the role of hair in investigations, how FTIR can be used to determine the chemical composition of hair through a small sample size, and the typical morphological and chemical composition of hair. It then outlines five common chemical treatments for hair - dye, bleaching, waxing, straightening, and chlorine oxidation - and how they affect the molecular structure and can be detected using FTIR. The document concludes that FTIR is an important forensic technique that can reveal differences in hair samples due to chemical damage, weathering, and cosmetic treatments.

1. Analysis of Synthetic Compounds
on Hair by Using FTIR for
Forensics Purpose
Honour Seminar Presentation (SCS 4901)
Islamic Science University of Malaysia (USIM)

2. Introduction
Hair in Forensic
Role of hair in investigation
- Trace elements
- Secondary transfer
Role of FTIR in investigation
- Can provide rapid and specific chemical
composition
- Small quantity of sample needed (suitable for
limited quantity of trace elements)

3. Introduction
The white color on hair commonly gives an old appearance to people
and they tend to do hair treatment in order to look fresh and versatile.
Moreover, not only women, but also men change their hair color to
look attractive and get new image in represent self-confidence and
social success.
There are abundance of chemical compounds used in the hair treatment that
will affect the molecular structure of the hair fiber. It can be detected by using
Fourier Transform Infrared Spectroscopy (FTIR).

4. Hair Morphological Composition
- Outermost layer of hair fiber
The Cuticle
- Important in chemical resistance, protection and stability of hair
- Shows the age of hair
The Cortex
- The larger portion of hair by mass and volume
- Important in mechanical aspect and properties of hair fiber
- Contain melanin
- Inner part with diameter 5-10µm
The Medulla
- Important in thermal insulation and resistance to alkali
- Contains pigment granules (pheomelanins and eumelanins)

5. Hair Chemical Composition
Elements Pigments
• C, H, O, N and S are main • Determine the color
elements • Eumelanin give light color
• Sweet deposits, environment • Pheomelanin give dark color
and metabolic irregularities
are primary root of trace
elements
Lipids Proteins
• Free lipids • Main composition in hair
• Important for the condition • Depend on the individuals diet
known as oily hair • 20 amino acid presents in
protein

6. Treated and Untreated Hair
There are five types of chemical treatments
Oxidation
Dye Bleaching Waxing Straightening with Chlorine

7. Cont.
 Dye – permanents, semi-permanents and temporary
(oxidative species containing phenylenediamines, aminophenols,
dihydroxybenzenes, and nitro compound)
 Bleaching – alkaline medium, hydrogen peroxide and ammonium
 Waxing – total reconstruction with ammonia and ammonium hydroxide
 Hair straightening – strong base such as such as sodium hydroxide
 Oxidation with chlorine - There are 2 oxidising species whether Cl2 and
HOCl that will cleave peptide bond and disulphide bond depending in the pH
of water

8. The Principle of Methodology
• Obtain hair sample from the donor
• Cut into certain length
1
• Flattened with roller knife
• Transferred to bottom KBr salt plate
2
• Second KBr plate placed on the top
• Run with FTIR and collect the reading of spectrum
3

9. Fourier Transform Infrared
Spectroscopy (FTIR)
- High resolution
- High scan rate
Improved infrared Has movable and
spectra stationary mirror. - Respond only to
modulated light

12. Conclusion
Infrared spectroscopy is an important technique for aiding forensic
scientists in their investigations. Individual hair fibers can easily be
analyzed, and differences due to chemical damage, natural
weathering, and cosmetic treatments are readily apparent.
It is also provide an information about functional group that help
the researcher or investigator to predict the chemical compound.

13. The End
 Thank You
Honour seminar Presentation
(7/12/2012)