SPECTROSCOPY -DHARMASHA VARDHINI

2. CONTENT
SPECTROSCOPY
TYPES OF
SPECTROSCOPY
ATOMIC AND
MOLECULAR
SPECTROSCOPY

4.  The study of molecular structure and
dynamics through the Absorption, Emission
and Scattering of light.

5.  The study of interaction between Matter and
Electromagnetic (EM) Radiations.
 Matter: Anything which occupies space in
universe and having mass is called
Matter.

6.  The visible light dispersed according to its
wavelength or frequency.
 It is also used in Astronomy and Remote
Sensing on Earth.

7.  There are two types of Spectroscopy
(a) Atomic Spectroscopy
(b) Molecular Spectroscopy

8. ATOMIC SPECTROSCOPY

9.  Atomic Spectroscopy is the study of the
electromagnetic radiations absorbed and
emitted by atoms.
 Atomic Spectroscopy is a type of spectroscopic
technique which is used for both quantitative
and qualitative analysis of an element present
sample through mass spectrum.

10.  It can be divided by Atomization source or by
the type of spectroscopy used.
 There are different variations of atomic
spectroscopy emission, absorption,
fluorescence and mass spectroscopy.

11.  There are two types of atomic spectroscopy
(a) Atomic Absorption Spectroscopy
(b) Atomic Emission Spectroscopy

13.  Atomic absorption spectroscopy is based on
absorption of light by free metallic ions.
 Atomic absorption spectroscopy quantifies
the absorption of ground state atoms in the
gaseous state.

14.  The atoms absorb ultraviolet or visible light
and make transitions to higher electronic
energy levels.
 According the Beer-Lambert law directly in
AAS is difficult due to variations in the
atomization efficiency from the sample
matrix.

16.  Atomic Emission Spectroscopy (AES or OES)
uses quantitative measurement of the optical
emission from excited atoms to determine
the concentration.
 The atoms decay back to lower levels by
emitting
light.

17.  This method is chemically analysis that uses
the intensity of light emitted from a flame,
plasma, arc at a particular wavelength to
determine the quantity of an element in a
sample.
 It is one of the most useful and commonly
used
technique for analyses of metal and non-
metals.

18.  Molecular Spectroscopy involves the
interaction of electromagnetic radiation with
materials in order to produce an absorption
pattern.

19.  Types of molecular spectrum
(a) NMRs
(b) Ultraviolet Visible Spectroscopy
(c) Infrared Spectroscopy

21.  NMR spectroscopy is based on the
measurement of absorption of
electromagnetic radiation in the radio-
frequency.
 Nuclei of atom rather than outer electrons
are involved in the absorption process.

23.  The wavelength of UV and visible light are
substantially shorter than the wavelength of
infrared radiations.
 Molecule or ion absorbs ultraviolet or visible
radiation it undergoes a change in its valence
electron transition.

25.  Infrared Spectroscopy involves the interaction
of infrared radiation with matter.
 The method or technique of infrared
spectroscopy is conducted with an
instruments called an infrared spectrometer.

26.  A common laboratory instruments that uses
this technique is a Fourier transform infrared
(FTIR) spectrometer.
 Infrared spectroscopy has also been
successfully utilized in the field of
semiconductor microelectronics.