Spectroscopy is the study of the interaction of electromagnetic radiation with matter. There are different types of spectroscopy including atomic spectroscopy, which studies atomic absorption and emission, and molecular spectroscopy, which analyzes interactions with molecules. Common molecular spectroscopy techniques are UV-Vis, IR, NMR, and mass spectrometry. UV-Vis, IR, and NMR spectroscopy analyze absorption and emission patterns to determine structural information, while mass spectrometry separates ions by their mass-to-charge ratio. Spectroscopy has various applications in analytical chemistry, medicine, materials analysis, and other fields.

1. SPECTROSCOPY
B Y ,
L O K E S W A R I B
B S C - B I O T E C H N O L O G Y
B O N S E C O U R S C O L L E G E F O R W O M E N
T H A N J A V U R

2. ABOUT SPECTROSCOPY;
#Spectroscopy is a branch of science
which studies the interaction of
electromagnetic radiation with matter
where the interaction of radiation with
chemical species is measured to obtain
characteristics quality and quantity of
the species.

3. a)Atomic
spectroscopy
1)Atomic
absorption
2)Atomic
emission
b)Molecular
spectroscopy
1)UV-Vis
2)IR
3)NMR
4)MS

4. A)ATOMIC SPECTROSCOPY
Atomic spectroscopy is based upon the absorption and
emission of electromagnetic radiation by atomic particle.
a)The first step in all atomic spectroscopic procedures is
atomization.
*Atomization is a process in which a sample is
volatilized and decomposed to produce gas-phase atoms
and ions.
*It is a critical step in all atomic
spectroscopy.

5. A)
1)ATOMIC ABSORPTION SPECTROSCOPY:
It is a type of elemental analysis based on excitation of electron of atom.
2 fundamentals during application of AAS:
*sample preparation and introduction,
*sample atomization
#Many samples like solid,animal tissue,plant leaves,minerals etc.,are not
directly used as sample and rather they should be prepared as solution by
extensive preliminary treatment.
#After sample is prepared from of clear solution ,if it introduced to the
instrument for atomization process.In the atomization process sample is
nebulized(conversion of samples to mist, ie small droplets of solution) by a
flow of gaseous oxidant (eg; air oxygen,nitrogen) mixed with gaseous
fuel(eg:naturalgas,hydrogen,ethylene)

7. COMPARISON OF AAS AND AES
AAS
 PROCESS MEASURED
# Absorption
(light absorbed by
unexcited atom)
 USE OF FLAME
#Atomization
 INSTRUMENTATION
#Uses of light
source
 BEER’S LAW
#Applicable
AES
#Emission (light emitted
by exited atoms)
#Atomization and
excitation
#Do not use light
source
#Not applicable

8. MOLECULAR SPECTROSCOPY;
Molecular spectroscopy involves the
interaction of electromagnetic
radiation with materials in order to
produce an absorption pattern (i.e. a
spectrum) from which structural or
compositional information can be
deduced.
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9. ULTRA VIOLET VISIBLE SPECTROSCOPY
 Ultraviolet–visible spectroscopy or ultraviolet–visible
spectrophotometry (UV–Vis or UV/Vis) refers
to absorption spectroscopy or reflectance spectroscopy in
part of the ultraviolet and the full,
adjacent visible spectral regions.
 This means it uses light in the visible and adjacent ranges.
The absorption or reflectance in the visible range directly
affects the perceived color of the chemicals involved.
 In this region of the electromagnetic spectrum , atoms
and molecules undergo electronic transitions .
 Absorption spectroscopy is complementary
to fluorescence spectroscopy, in that fluorescence deals
with transitions from the excited state to the ground
state, while absorption measures transitions from the
ground state to the excited state.

10. PRINCIPLE OF ULTRAVIOLET-VISIBLE
ABSORPTION
 Molecules containing bonding and non-bonding electrons (n-
electrons) can absorb energy in the form of ultraviolet or visible
light to excite these electrons to higher anti-bonding molecular
orbitals.
 The more easily excited the electrons (i.e. lower energy gap
between the HOMO and the LUMO), the longer the wavelength
of light it can absorb.
 There are four possible types of transitions (π–π*, n–π*, σ–σ*,
and n–σ*), and they can be ordered as follows :σ–σ* > n–σ* > π–π*
> n–π*.

11. APPLICATIONS;
UV/Vis spectroscopy is routinely used
in analytical chemistry for
the quantitative determination of
different analytes, such as transition
metal ions, highly conjugated organic
compounds, and biological
macromolecules. Spectroscopic analysis
is commonly carried out in solutions but
solids and gases may also be studied.

12. INFRA RED SPECTROSCOPY;
Infrared spectroscopy (IR spectroscopy) is
the spectroscopy that deals with
the infrared region of the electromagnetic
spectrum, that is light with a longer
wavelength and lower frequency than visible
light. It covers a range of techniques, mostly
based on absorption spectroscopy.

13. PRINCIPLES OF IR 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.

14. APPLICATIONS 0F IR SPECTROSCOPY;
Infrared spectroscopy is widely used
in industry as well as in research. It
is a simple and reliable technique for
measurement, quality control and
dynamic measurement. It is also
employed in forensic analysis in civil
and criminal analysis.

15. NMR SPECTROSCOPY;
Nuclear Magnetic Resonance is an
analytical chemistry technique used in
quality control and reserach for
determining the content and purity of
a sample as well as its molecular
structure. For example, NMR can
quantitatively analyze mixtures
containing known compounds.

16. APPLICATIONS;
Nuclear magnetic resonance
spectroscopy is widely used to determine
the structure of organic molecules in
solution and study molecular physics,
crystals as well as non-crystalline
materials. NMR is also routinely used in
advanced medical imaging techniques,
such as in magnetic resonance imaging
(MRI).

17. MASS SPECTROMETRY;
Mass spectrometry is an analytical
technique that measures the mass-
to-charge ratio of ions. The results
are typically presented as a mass
spectrum, a plot of intensity as a
function of the mass-to-charge
ratio.

18. PRINCIPLE OF MASS SPECTROSCOPY;
A mass spectrometer generates
multiple ions from the sample
under investigation, it then
separates them according to their
specific mass-to-charge ratio
(m/z), and then records the
relative abundance of each ion
type.

19. COMPONENTS OF MASS
SPECTROMETRY

21. USES OF MASS SPECTROSCOPY;
A mass spectrum is a plot of the ion signal
as a function of the mass-to-charge ratio.
These spectra are used to determine the
elemental or isotopic signature of a
sample, the masses of particles and of
molecules, and to elucidate the chemical
identity or structure of molecules and
other chemical compounds.