infrared spectroscopy, principle, instrumentstion, graph,applications.

1. INFRARED SPECTROMETER

2. INTRODUCTION
 Infrared spectroscopy (IR spectroscopy or vibrational
spectroscopy) is the interaction of infrared radiation
with matter
 . It covers a range of techniques, mostly based on absorption
spectroscopy. As with all spectroscopic techniques, it can be
used to identify and study chemical substances. Samples
may be solid, liquid, or gas.
 The method or technique of infrared spectroscopy is
conducted with an instrument called an infrared
spectrometer to produce an infrared spectrum.
 An IR spectrum can be visualized in a graph of infrared
light absorbance on the vertical axis vs. frequency or
wavelength on the horizontal axis.

3. Principle Of Infrared
Spectroscopy
 The IR spectroscopy theory utilizes the concept that
molecules tend to absorb specific frequencies of light that
are characteristic of the corresponding structure of the
molecules. The energies are reliant on the shape of the
molecular surfaces, the associated vibronic coupling, and the
mass corresponding to the atoms.
 For instance, the molecule can absorb the energy contained
in the incident light and the result is a faster rotation or a
more pronounced vibration.

4. INSTRUMENTATION
 In infrared spectra the absorption peaks point downward
because the vertical axis is the percentage transmittance of
the radiation through the sample. Absorption of radiation
lowers the percentage transmittance value. Since all bonds
in an organic molecule interact with infrared radiation, IR
spectra provide a considerable amount of structural data.
 There are four types of instruments for infrared absorption
measurements available:

-Dispersive grating spectrophotometers for qualitative
measurements
-Nondispersive photometers for quantitative determination of
organic species in the atmosphere
-Reflectance photometers for analysis of solids
-Fourier transform infrared (FT-IR) instruments for both
qualitative and quantitative measurements.

6.  Infrared light sources
 The Nernst glower
 The globar source
 The carbon dioxide laser
 Detectors
 Bolometer
 Sample holder
INSTRUMENTS IN
INFRARED
SPECTROMETER

7. GRAPH OF INFRARED
SPECTROSCOPY

8. APPLICATIONS
 To compare spectrum.
 No two sample will have identical IR spectrum.
 Used for determination of molecular structure.
 To study the progress of reaction.
 Detection of impurities.
 Study isomerism in organic chemistry.
 Identify the shape of symmetry of molecule

9. THANKYO
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