Atomic Emmision Spectroscopy

1. ATOMIC EMISSION
SPECTROSCOPY
COUSE TITILE: ADVANCE ANALYTICAL TECHNIQUES - 1
COURSE CODE: ICM 1002
GROUP NO: 01
NAME – MOHD WAHID
ROLL NO-2016-ICM-04
ENROLL NO-GD 9740

2. INTRODUCTION
• Used as standard method for the metal
analysis
• In atomic emission small part of sample
is vaporized from free atom that attain
energy from excitation source results in
transition from lower to higher energy
state on returning back emit a photon of
radiation

3. PRINCIPLE OF ATOMIC
EMISSION
SPECTROSCOPY
AND
SCHEMATIC DIAGRAM OF
INSTRUMENTATION

4. Principle
• The electrons of an atom moves from
higher energy level to lower energy level,
they emit extra amount of energy in the
form of light which is consist of photons.

7. Instrumentation
Comprises on:
• Source & Sample
• Atomizer
• Monochromator
• Detector & readout device

8. Schematic Diagram Of Instrumentation

10. COMPONENTS
1. Light source
a. Inductively coupled plasma (ICP)
b. Direct current plasma (DCP)
c. Flame
d. Arc and spark

11. Plasma Source
“ Plasma is defined as a neutral gas
containing significant number of both
positive and negative ions or free
electrons”

12. Mechanism Of Inductively Coupled
Plasma
• The inductively coupled plasma torch
consist of 3 concentric silica quartz tube.
• Argon stream that carries the sample in
the form of an aerosol, passes through the
central tube.
• Plasma is initiated by a spark from a tesla
coil. Argon gas ionized and emission is
measured.

15. Laser Induced Plasma
• In this source highly energetic laser pulse
used to generated optical sample excitation.
• When laser beam focused on the small spot
on a sample(liquid, solid and gases).
• The temperature of heated region is rise
rapidly that vaporized the sample material &
induced plasma formed .
• vaporized material excited & emit radiation.

16. Laser Beam Excitation

17. Microwave Induced Plasma
• Used for multi-analytic determination of
major to minor elements.
• Employed microwave energy to produced
plasma.
• MIP generated from few hundred watts of
radiation source
• Atomized sample pass through plasma &
promote electron excitation .

18. ATOMIZER
AND
SAMPLE
HANDLING

19. Atomizer
• Elements to be analyzed needs to be in
atomic state.
• Atomization; Conversion of sample (maybe;
solid or liquid) into free gaseous atom.
• Atomizer; Device used for atomization

20. TYPES OF ATOMIZER
FLAME ATOMIZER
CONTINUOUS DISCRETE
ELECTRO-THERMAL
ATOMIZER

21. 1. Flame Atomizer
• To produce flame, required oxidant gas
and flame gas.
• Mostly the air-acetylene flame or nitrous
oxide- acetylene flame is used.
• Liquid or dissolved samples are typically
used with flame atomizer.

22. Flame Atomization

23. 2. Electro-thermal Atomizer
• Also known as “Graphite Furnace
Atomizer”
• More convenient to uses a non-flame
method i.e. electrically heated graphite
tube.

24. Atomization Of Sample
DRYING
• drying of sample
into solid
deposit.
• by heating
graphite tube at
110 ºC.
ASHING
• conversion of
organic matter in
CO2 and H2O
&volatilization
of inorganic
matter.
• by heating
graphite tube at
350-1200 ºC.
ATOMIZATION
• leads to gaseous
atom
• by raising the
temperature up to
2000-3000 ºC.

25. Sample Handling
• The droplets of sample introduced in
atomizer should be of constant size.
• The temperature should be maintained to
obtain good reproducibility.
• The speed of introducing sample must be
equal to certain permissible band values.
• Sufficient sample volume should be
available for maximum efficiency

26. Monochromator
• It is a device use to transmit narrow band
of wavelength which is chosen from
wavelength of wider range available.
• Types of monochromator:
• Prism Monochromator
• Grating Monochromator

27. DETECTORS

28. Phototube (Photo Electric Cell)
• Glass filled or vacuum tube
• Sensitive to light
• Depend on frequency and intensity of incoming
photon
• Need amplifier. But are replaced by
photomultiplier detectors.

29. Photo Multiplier Detector
• Vacuum phototubes, are extremely
sensitive detectors of light in the ultra
violet, visible, and near-infrared
region ranges of the electromagnetic
spectrum.

31. APPLICATION

32. Applications
• It is used for rapid analysis of
multi-component pharmaceutical tablet.
• It is used for elemental analysis.
• It is used primarily for the identification
and determination of metals in traces
amount.

33. • It is used for determination of mineral
composition of igeous and metamorphic
rock.
• It is used for routine analysis of wear
metals in lubricating oils.
• It is used for the analysis of sodium,
potassium and lithium.

34. CONCLUSION
The emission spectrum of a chemical element or chemical compound is the spectrum of
frequencies of electromagnetic radiation emitted due to an atom or molecule making a
transition from a high energy state to a lower energy state. The photon energy of the
emitted photon is equal to the energy difference between the two states. There are many
possible electron transitions for each atom, and each transition has a specific energy
difference. This collection of different transitions, leading to different radiated
wavelengths, make up an emission spectrum. Each element's emission spectrum is
unique. Therefore, spectroscopy can be used to identify the elements in matter of
unknown composition. Similarly, the emission spectra of molecules can be used in
chemical analysis of substances.
REFFERENCES
1. Principals of Instrumental Analysis, D.A.Skoog, F.J.Holler, T.A Nieman, Vth edn,
Thomson Brooks/Cole,1998.
2. Instrumental methods of Chemical analysis, G.W.Ewing, Vth edn, Mc-Graw Hill
Book Co, New Delhi, 1985.