2. Gamal A. Hamid Toeveryone who hashelped uswith support, new
books,hard / software Andoverthe internet Special thanks for THERMO
Thanks 2
3. Gamal A. Hamid Contents Introduction Theory of FTIR Types of
vibration Instrumentation Sample preparation Accessories Advantages
Applications 3
4. Gamal A. Hamid 4
5. Gamal A. Hamid 1-Energy 2-Matter 3-Interaction Chemistry is
the science of study the interaction between energy and matter
Chemistry 5
6. Gamal A. Hamid Spectroscopy spectroscopy is the science of
study the interaction between radiation and matter 6
7. Gamal A. Hamid 7
8. Gamal A. Hamid 1. Radiation The electromagnetic spectrum The
Electric and Magnetic fields are Oscillating in single planes at
right angles to each others 8
9. Gamal A. Hamid Electromagnetic Radiation Energy propagated
through free space or through a material medium in the form of
electromagnetic waves. 9
10. Gamal A. Hamid IR Radiation Electromagnetic radiation at
wavelengths longer than the red end of visible light and shorter
than microwaves (roughly between 1 and 100 microns). Almost none of
the infrared portion of the electromagnetic spectrum can reach the
surface of the Earth. Our skin emits infrared light, which is why
we can be seen in the dark by someone using night vision goggles.
10
11. Gamal A. Hamid No. Region Range Vibrational / Rotational
Information 1 Near IR 14000 - 4000 Changes in Vibrational and
rotational levels, electron transitions 2 Mid-IR 4000 - 400 Changes
in fundamental Vibrational levels of most molecules 3 Far-IR 400 -
20 Rotational energy level changes IR Regions 11
12. Gamal A. Hamid The Tested samples Paints , Pigments,
Polymers, Drugs Food additives ,Air polluents, Plasticizers, Rubber
and Plastics 2. Matter 12
13. Gamal A. Hamid 3. Interaction Molecular Excitation
Molecules are formed by the combination of two or more atoms.
Unlike atoms, molecules can be subdivided to individual atoms.
Atomic Excitation An atom is smallest particle in an element that
has the properties of the element. In nuclear, atomic, and
molecular systems, the excited states are not continuously
distributed but have only certain discrete energy values. Thus,
external energy (excitation energy) can be absorbed only in
correspondingly discrete amounts. 13
14. Gamal A. Hamid 3. Interaction As an electromagnetic field
propagates through a sample, there will be a certain average
excited state population that will have a coherent and an
incoherent component. At all times, the excited state has the
option of simply relaxing spontaneously and emitting a photon.
Energy of molecule (E total ) E total = 4 E 1. E Electronic motion
2. E Rotational motion 3. E Translational motion 4. E Vibrational
motion 14
15. Gamal A. Hamid Number of motions Degree of freedom for
polyatomic molecules No. Motion Linear Non-linear 1 Translation 3 3
2 Rotational 2 3 3 Vibrational 3N-5 3N-6 4 Total 3N 3 N Where N is
the number of atoms 15
16. Gamal A. Hamid I. Electronic motion The electronic
component is linked to the energy transitions of electrons as they
are distributed throughout the molecule, which is the result of the
absorption of energy within the NIR regions. 16
17. Gamal A. Hamid II. Rotational motion Rotational energy,
which gives rise to its own form of spectroscopy, is observed as
the tumbling motion of a molecule, which is the result of the
absorption of energy within the microwave and NIR regions. 17
18. Gamal A. Hamid III. Translational motion The translational
energy relates to the displacement of molecules in space as a
function of the normal thermal motions of matter. 18
19. Gamal A. Hamid IV. Vibrational motion The absorption of the
electromagnetic radiation by matter leads to many Type of
vibrations 1. The dipole moment of the molecule must change during
the vibration. 2. Homonuclear diatomic molecules such as Hydrogen
(H2), Nitrogen (N2) and Oxygen (O2) no infrared absorption is
observed because its dipole moment remains zero. 19
20. Gamal A. Hamid Molecular vibrations 1. The positions of
atoms in a molecules are not fixed. 2. The Vibrational corresponds
to the absorption of energy by a molecule 3. Main categories of
stretching and bending. 20
21. Gamal A. Hamid Stretching Change in inter-atomic distance
along bond axis Stretching absorptions usually produce stronger
peaks than bending 21
22. Gamal A. Hamid Bending Change in angle between two bonds.
1. Twisting 2. Rocking 3. Wagging 4. Scissoring Twisting Rocking
Wagging Scissoring 22
23. Gamal A. Hamid IR Chart This Chart is a result of
interaction bet. IR-radiations and matter. 23
24. Gamal A. Hamid Four regions of Chart 1. 3700 2500 cm-1
Single bonds to hydrogen 2. 2300 2000 cm-1 Triple bonds 3. 1900 -
1500 cm-1 Double bonds 4. 1400 - 650 cm-1 Single bonds (other than
hydrogen) 24
25. Gamal A. Hamid Fingerprint region 1- The region to the
right-hand side of the diagram (from about 1650 to 500 cm-1) 2-
Usually contains a very complicated series of absorptions 3-
Contains peaks due to bending vibrations 4- It is rarely possible
to assign a specific peak to a specific group. 25
26. Gamal A. Hamid Properties of peaks 1. Intensity (weak,
medium or strong), 2. Shape (broad or sharp), and 3. Position
(cm-1) in the spectrum. 26
27. Gamal A. Hamid Peaks Properties
Absorbance%TransmissionDesignation >1.3 ~0.6 ~0.3 ~0.2 ~0.1
~0.07 ~0.02 ~0.01 98 VVS VS S M MW W VW VVW 27
28. Gamal A. Hamid Definitions Wavelength The wavelength is the
distance between two identical points on two adjacent identical
waves in a beam. Wave number Wave number is defined as the
reciprocal of the wavelength expressed in cm. Units are cm-1. Wave
numbers are normally the units along the X-axis in Infrared
spectra. 28
29. Gamal A. Hamid Fourier Transform Infrared Spectroscopy FTIR
A method of obtaining an Infrared spectrum by measuring the
interferogram of a sample using an interferometer, then performing
a Fourier Transform upon the interferogram to obtain the spectrum.
29
30. Gamal A. Hamid 30
31. Gamal A. Hamid Instrumentation Source Laser Interfero meter
Detector 31
32. Gamal A. Hamid 1. Source The source The Ever Glo energy
source can be used to collect data in the mid-and far-infrared
spectral ranges. 32
33. Gamal A. Hamid 2. Laser Purpose The Laser source produce a
single beam with a definite wave length for internal calibration.
33
34. Gamal A. Hamid 3. Interferometer The heart of the
spectrometer An device in which two or more radiation beams
interfere with each other after passing through different optical
paths. The interferometer produces a unique type of signal which
has all of the infrared frequencies encoded into it. The output is
an interferogram or interference record. The two domains of
Distance and Frequency are inter convertible by the mathematical
method of Fourier transformation. 34
35. Gamal A. Hamid Michelson Interferometer The Michelson
interferometer, which is the core of FTIR spectrometers, is used to
split one beam of light into two so that the paths of the two beams
are different. Then the Michelson interferometer recombines the two
beams and conducts them into the detector where the difference of
the intensity of these two beams are measured as a function of the
difference of the paths. 35
36. Gamal A. Hamid An optical device causing two beams of light
to travel different distances to produce an optical path
difference. This allows constructive and destructive interference
to occur, and changing the optical path difference allows the
measurement of an interferogram. consists of A. beam splitter
semi-reflecting B. fixed mirror C. moving mirror 36
37. Gamal A. Hamid A. Beam Splitter The beam splitter is made
of a special material that transmits half of the radiation striking
it and reflects the other half. Radiation from the source strikes
the beam splitter and separates into two beams. One beam is
transmitted through the beam splitter to the fixed mirror and the
second is reflected off the beam splitter to the moving mirror. The
fixed and moving mirrors reflect the radiation back to the beam
splitter. Again, half of this reflected radiation is transmitted
and half is reflected at the beam splitter, resulting in one beam
passing to the detector and the second back to the source. 37
38. Gamal A. Hamid Mirrors B. Stationary Mirror The stationary
mirror in an FTIR interferometer is nothing more than a flat highly
reflective surface. C. Moving Mirror There is present only one
moving part in an FTIR spectrometer, its oscillating mirror. Air
bearings are used in FTIR spectrometers because of the higher speed
that the oscillating mirror is required to move at. 38
39. Gamal A. Hamid 4. Detector DTGS Deuterium tri glycine
sulphat in a temperature resistance alkali halide window MCT
Mercury cadmium telluride (sensitive work) The detector has to be
coated to liquid nitrogen The output from the detector goes to a
preamplifier where it is converted into a voltage signal varying
with time. 39
40. Gamal A. Hamid Calibration Polystyrene IUPAC: Tables of
wave numbers for the calibration of IR spectrometers Wave number
Intensity 3027.1 9 2924 10 2850.7 7 1944.0 3 1871.0 3 1801.6 3
1601.4 9 1583.1 5 1495 10 1454 10 Wave number Intensity 1353 5 1332
5 1282 3 1181.4 4 1154.3 4 1069.1 6 1028.0 8 906.7 3 842 3 752 10
698.9 10 40
41. Gamal A. Hamid 41
42. Gamal A. Hamid Sample Preparation Infrared Reflectance
Spectroscopy 1. Attenuated Total Reflection 2. Diffuse Reflectance
3. Specular reflectance Infrared Transmission Spectroscopy 1.
Transmission Solid 2. Transmission liquid 3. Transmission gas I.
Transmission radiation passes through a sample II. Reflectance
Radiation reflected from the sample surface. 42
43. Gamal A. Hamid Sample Preparations Transmission Reflectance
43
44. Gamal A. Hamid I. Infrared Transmission Spectroscopy 1.
Transmission Solid 2. Transmission liquid 3. Transmission gas
44
45. Gamal A. Hamid 1. Transmission Solid 1. 2 mg sample powder.
2. 300 mg KBr( spectroscopic grade) into an agate mortar. 3. Grind
the powders together until it become like fine flour. 4. Transfer
the ground mixture into the cylinder bore. 5. Place the die
assembly into a hydraulic press. 6. Increase pressure in the press
to 15 tons . Potassium Bromide disk 45
46. Gamal A. Hamid 7. Carefully release the vacuum, and remove
the die from the press. 8. Dismantle the die, and transfer the KBr
disk to a spectrometer disk holder Avoid touching the faces of the
disk. 9. Mount the disk holder in the spectrometer. 46
47. Gamal A. Hamid 1. Uneven distribution in powder in die 2.
Too much sample 3. Too much KBr powder 4. Poorly dispersed sample
5. Water in die 6. Pressed at too low pressure or at too low time
If the disk is not translucent 47
48. Gamal A. Hamid The appearance of the spectra depends on 1.
The relative amounts of surface reflection (particle size) 2.
Radiation that has penetrated the sample 48
49. Gamal A. Hamid The flattened turning point and do not reach
0 % T, this is caused by a poorly dispersed sample or holes in the
disk. Sloping baseline is usually due to a poorly dispersed sample.
49
50. Gamal A. Hamid 2. Transmission Liquid The simplest and most
common method of sample preparation A drop of the sample is placed
between two potassium bromide or sodium chloride circular plates,
This produce a thin capillary film. The plates are then placed in a
holder ready for analysis. 50
51. Gamal A. Hamid 1. The sample is ground using an agate
mortar and pestle to give a very fine powder 2. A small amount is
then mixed with Nujol to give a paste . 3. Several drops of this
paste are then applied between two sodium chloride plates (these do
not absorb infrared in the region of interest). 4. The plates are
then placed in the instrument sample holder ready for scanning.
Nujol Mull 51
52. Gamal A. Hamid The infrared spectrum of a thin film can be
easily obtained by placing a sample in a suitable holder, such as a
card with a slot cut for the sample window. This method is often
used for checking the calibration of an instrument with a
polystyrene sample Thin film 52
53. Gamal A. Hamid Liquid Cells Ideal for the quantitative
analysis of hydrocarbons in water and soil samples or for the
analysis of additive content in polymers after extraction. Sample
extracts are easily transferred to the quartz cells for infrared
analysis. For analysis of polymer additives after extraction
Highest quality quartz cells for clear infrared spectral
transmission and optimized result 53
54. Gamal A. Hamid 3.Transmission Gas Use of a cylindrical gas
cell with windows at each end composed of an infrared inactive
material such as KBr, NaCl or CaF2. The cell usually has an inlet
and outlet port with a tap to enable the cell to be easily filled
with the gas to be analyzed. 54
55. Gamal A. Hamid Advantages of Transmission 1. Does not
require an additional accessories. 2. Used in the collection of
many reference library spectra. 3. Ideal for quantitative
measurements. 4. Does not require extensive training. 55
56. Gamal A. Hamid II. Infrared Reflectance Spectroscopy 1.
Attenuated Total Reflection 2. Diffuse Reflectance 3. Specular
reflectance 56
57. Gamal A. Hamid 1. Attenuated Total Reflection The beam is
directed onto optical dense crystal , internal reflectance create
waves that extend to the sample in contact with crystal surface.
Horizontal Vertical 57
58. Gamal A. Hamid HATR Used in the analysis of liquid,
semi-liquid materials and a number of solids. HATRs feature a
constant and reproducible effective path length and are well suited
for both qualitative and quantitative applications. In general,
sampling is achieved by placing the sample onto the HATR crystal
generally eliminating sample preparation. 58
59. Gamal A. Hamid 2. Diffuse Reflectance Sample cup filled
with mixture of sample and KBr IR radiation interact with sample
particles, then reflecting External reflectance off their surfaces
causing diffuse and scattering of radiation. standard 11 mm
diameter cup, a micro 4 mm diameter cup, and tilted cups. The
tilted cups allow for collection of total reflectance, diffuse and
specular components. In addition, an abrasive sampler, 12 mm
diameter, can be used with Diabrase pads to allow quick and easy
sample preparation of intractable solids. 59
60. Gamal A. Hamid 3. Specular reflectance The principle of
specular reflectance depending on the change of the refractive
index of sample which varies with frequency of light to which it is
expose. When reflected light is scattered by the sample it is
called diffuse reflection. When it is reflected directly, it is
called specular reflection 60
61. Gamal A. Hamid 61
62. Gamal A. Hamid Agate Pestle and Mortar Agate Mortar 4 cm
diameter bowl and Pestles are the ideal tool for manually grinding
solid samples with an appropriate mull agent (such as KBr powder,
Nujol, or Fluorolube) in preparation for mull FTIR transmission
analysis, diffuse reflectance, and KBr pellet press applications.
Pure agate is non-absorbing in the infrared spectroscopic region.
Specac Mortar and pestle sets are available at 40 mm diameter as
standard. 62
63. Gamal A. Hamid Pellet Dies These are particularly well
suited for the preparation of solid KBr pellets for FTIR molecular
spectroscopic analysis These Pellet Dies produce circular pellets
in sizes from 5 mm to 40 mm diameter as standard 63
64. Gamal A. Hamid Hydraulic Press Manual Hydraulic Press is
available in 15 and 25 ton load configurations. The press has a
compact, small footprint design making it ideal for bench-top and
glove box laboratory applications. With a rigid steel construction,
and protective safety shield as standard, this laboratory hydraulic
press is particularly well-suited for FTIR KBr pellet press.
64
65. Gamal A. Hamid Transmission Sampling Kit Comprehensive
Transmission Sampling Kit (CTS) Gases, Solids and Liquids.
Includes: Sample preparation tools, mull liquids, cells. windows
and cell holders required for preparation and analysis of gas,
solid and liquid samples. 65
66. Gamal A. Hamid Smart accessories 1. High speed and ease to
use. 2. Highest quality data and the greatest degree of
flexibility. 3. Automatic setting of accessory. 4. More
reproducible and reliable. 5. Samples analyzed in their natural
status. 6. Excellent for thick samples. 66
67. Gamal A. Hamid Heating Gas cell 1. Analyzes gaseous samples
and vapors from room temperature to250 C. 2. The cell is an
evacuable stainless steel chamber with an injection septum sample
introduction port. 3. It is heated by a low voltage heater
surrounding the body. 4. The temperature can be measured with a
thermocouple passing through a vacuum tight seal into the gas
cavity. 67
68. Gamal A. Hamid Advanced Liquid Transmission Cells Advanced
Liquid Transmission Cells in sealed, demountable, static, and flow
configurations to allow liquid samples to be studied at
temperatures other than ambient. A choice of window materials allow
for spectral analysis in the UV, Visible, NIR, and IR. 68
69. Gamal A. Hamid The High Temperature/High Pressure Cell 1.
The High Temperature/High Pressure Cell is a water cooled, that can
operate at up to 800 C and 1000 psi 2. It also allows the study of
vapors generated by the thermal decomposition of a sample. 69
70. Gamal A. Hamid Selector Environmental Chamber 1. This
accessory allows for the study of diffusely reflecting solid
samples in a controlled atmosphere ranging from ambient temperature
to 500 C, and vacuum (10-3 Torr) to 500 p.s.i. pressure. 2. The
standard chamber window is ZnSe, which gives a good balance between
IR transmiss 70
71. Gamal A. Hamid The Mill 1. The mill is used for the
production of the uniformly small and consistent particle size
necessary for successful preparation of KBr sample pellets. 2. It
can also be used in preparing samples for diffuse reflectance
spectroscopy. 71
72. Gamal A. Hamid The GladiATR Vision Sampling tool which
couples small area infrared analysis with simultaneous viewing.
Samples are placed face down and positioned on the diamond crystal
while its image is projected in real-time on the LCD screen.
Finding and optimizing the sample placement for specific analysis
areas is easy and fast! Analysis of thick or non-transparent
samples is no problem because viewing is through the diamond
crystal. 72
73. Gamal A. Hamid Infrared Window Materials
PropertiesRangeMaterialNo. Soft crystal- Insoluble in
water22,000-286AgBr1 Soluble-Low cost-Good
transmission40,000-400KBr2 Soluble-Low cost-Good
transmission40,000-625NaCl3 Hard crystal- Insoluble in
water5,500-600Ge4 73
74. Gamal A. Hamid 74
75. Gamal A. Hamid 1. Smart Searching Spectral databases have
become an integral part of the use of FT-IR equipment. With
spectral libraries, Both software packages allow you to create your
own user libraries as a standard feature. 75
76. Gamal A. Hamid 2. Smart Interpretation Built-in spectral
interpretation tools. These tools provide functional group
information for your spectrum. Information on over 100 common
functional groups 76
77. Gamal A. Hamid 3. Easy Maintaining You can minimize
downtime and service costs on your IR Series system.
User-replaceable components on your IR Series system will include:
Source Laser Detector Mirrors Power supply Desiccant 77
78. Gamal A. Hamid 4. FT-IR microscope Optional external beam
capability for the Centaurus TM FT-IR microscope. This
purpose-built system is ideal for routine analysis of samples as
small as 50 microns. 78
79. Gamal A. Hamid 5. Smart Accessories Powder or liquid
sampling Changeable crystals 79
80. Gamal A. Hamid 6. Easy Sampling All IR Series spectrometers
include a standard transmission accessory holder. In addition, the
sample compartment come ready for Foundation Series TM ATR Swap-
Top TM modules. for the most flexibility in FT-IR accessory
sampling techniques. 80
81. Gamal A. Hamid 7. Isolated optical system The cover reduces
the environmental effects on your spectra 81
82. Gamal A. Hamid 82
83. Gamal A. Hamid Interpretation of IR chart 1. Look for the
carbonyl C::O strong band at 1820-1660 cm- 2. This band is usually
the most intense absorption band in a spectrum. 3. If no C::O band
is present, check for alcohols . 4. for the broad OH band near
3600-3300 cm-1 and a C-O absorption band near 1300-1000 cm-1.
83
84. Gamal A. Hamid 5. If a C::O is present you want to
determine if it is part of an acid, an ester, or an aldehydes or
ketones. 6. (Acid ) O-H is present There will also be a C-O single
bond band near 1100-1300 cm-1. Look for the carbonyl band near 1725
-1700 cm-1. 7. (Ester) Look for C-O absorption of medium intensity
near 1300-1000 cm-1. There will be no OH 8. And continue to
interpretate the compound 84
85. Gamal A. Hamid Interpretation of IR chart Using the
software you can interpretate most of organic compounds 85
86. Gamal A. Hamid IR Chart 86
87. Gamal A. Hamid Tables 1 Frequency range, cm-1Compound
TypeBond 2960-2850(s) stretch AlkanesC-H 1470-1350(v) scissoring
and bending 3080-3020(m) stretch AlkenesC-H 1000-675(s) bend
3100-3000(m) stretchAromatic Rings C-H 870-675(s) bend Phenyl Ring
Substitution Bands 87
89. Gamal A. Hamid Air Pollution EPA Said The FTIR technology
shows promise since it has the capability to measure more than 100
of the 189 Hazardous Air Pollutants 89
90. Gamal A. Hamid Solvents analyses ATR-FTIR Solvents Library
: 630 selected spectra solvents selected from the Aldrich 90
91. Gamal A. Hamid Drugs analyses ATR-FTIR Pharmaceuticals,
Drugs & Antibiotics Library 1338 selected spectra 1. Active
substances . 2. Aids commonly used in pharmaceutical industry .
91