3. • Used as standard method for the metal
analysis
• In atomic emission small part of sample
is vaporized forms free atom that attain
energy form excitation source results in
transition from lower to higher energy
state on returning back emit a photon of
radiation
4. • Ancient: atomic emission was only based
on flame , arc or spark excitation sources.
• Modern era: advancement is made by the
introduction of non combustion plasma
sources
5. • Consist of discrete irregularly spaced
lines
• Spectra obtained from plasma ,arc or
spark excitation source are often highly
complex
6. PRINCIPLE OF ATOMIC EMISSION
SPECTROSCOPY
AND
SCHEMATIC DIAGRAM OF
INSTRUMENTATION
BY AYESHA KIRAN
(1416969)
7. 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.
14. COMPONENTS
1. Light source
a. Inductively coupled plasma (ICP)
b. Direct current plasma (DCP)
c. Flame
d. Arc and spark
BY GHOUSIAAROOJ
(1416984)
15. Plasma Source
“ Plasma is defined as a neutral gas
containing significant number of both
positive and negative ions or free
electrons”
16. 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.
17.
18.
19. Flame Source
Mechanism:
• It consist of total consumption burner in
which sample is drawn through a
capillary tube which injected directly into
flame and flame is high temperature
source that is used to desolvate and
vaporize a sample and generate free atom
for spectroscopic study.
20. Spark source
Mechanism:
• It consist of the primary circuit a voltage
of 110-220V is maintained. The high
voltage is obtained from setup
transformer which convert the line power
to 15000-40000V which then charge the
capacitor. When energy stored in the
capacitor, synchronous trigger the spark
between the electrodes.
21.
22. Continue
Light source
e. Arc and spark
f. Laser induced breakdown
g. Laser induced plasma
h. Microwave induced plasma
BY HIRA BILAL
(1416992)
23. Arc Discharge
DC ARC AC ARC
• Used for quantative analysis. • Also used for quantative analysis.
• Source is regulate supply is 110 to 220
V(tem p 4000 t0 8000K).
• In this alteration at a frequency of 60
HZ (2000 to 5oooV) that maintain by
transformer.
• When the sample (solid and liquid ) is
kept on the lower electrode in the arc
gap then start the current flow in the gap
& electrical arced is established which
responsible excitation.
• Once arc is picks out in the gap,
current flow start which arced the
sample and create excitation.
• Graphite electrodes is used and Less
sensitive.
• More sensitive.
24.
25. 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.
27. 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 .
29. 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
31. 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.
33. Sub-types Of Flame Atomization
a. Continuous Atomization; sample penetrate
the atomizer at constant speed.
a. not used for dissolved solid.*
b. Discrete Atomization; measured amount of
sample enters atomizer.
–effective when sample volume is limited.
34. Advantages;
• Reproducibility of sample and result.
Disadvantages;
• Only 5-15% of the nebulized sample reaches the
flame.
• A minimum sample volume of 0.5-1.0 ml is
needed to give a reliable reading.
• Viscous samples require dilution with a solvent.
35. 2. Electro-thermal Atomizer
• Also known as “Graphite Furnace
Atomizer”
• More convenient to uses a non-flame
method i.e. electrically heated graphite
tube.
36. Construction
• Serves as a sample cellGraphite Tube
• Metal jacket by which the water is circulated
Enclosed Water
Cooled Housing
• Made of quartz allow light to pass through
the tube
Transparent
Window
• Protect graphite tube from oxidation
Inert Pure Gas
Control
• Heating of graphite tubeElectrical Contact
37. 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.
38. Advantages;
• Small sample size
• Little or no sample preparation required
• Enhanced sensitivity
• Direct analysis of solid samples
Disadvantages;
• Loss of analyte during ashing stage
• Incomplete atomization
39. 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
41. 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
42. a. Prism
• When the light pass through prism it
emerges out in form of two lines or beam.
• To overcome this drawback two half
prism are placed.
• When light pass through first prism it
splits into two beams, when it reaches
second half prism recombines two beam
into single beam
43. b. Diffraction grating
• It gives better result and resolution.
• It replaced prism give linear dispersion.
• Problem occurred during the
identification of wavelength of emission
lines on photographic plate solved
through grating monochromator.
• Once we identify known reference line
and other lines identified automatically.
45. 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.
46. 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.
49. Atomic Emission Spectrometers
• Sensitivity is limited by noise.
• High luminosity and high resolution
monochromators necessary to isolate
spectral lines.
• Concave and plane grating use as
dispersive element.
• Echelle grating system use for high
resolution spectrograph.
50. Concave Grating
• Use for non scanning multi elements.
• Entrance and exit slit mounted on a
Rowland circle.
• Secondary optics consist of mirror behind
exit slit.
• Exit slit only pass spectral wavelengths.
51. • Large wavelengths cover by Paschen-
Runge mounting.
• To illuminate concave grating Wadsworth
mounting commonly use.
52. Plane Grating
• It is mostly use in AES instruments.
• Grating serve as dispersive element.
• Ebert mounting is use in large spectrometers
in which plane grating present.
• Standard grating has 600-1200lines/mm.
• Current AES has plane grating scanning
monochromators have 1500 lines/mm.
53. Echelle Grating
• Provide excellent dispersion and
resolution.
• Longest wavelength of lowest order
appear at bottom higher order at top.
• Two dimension permits high dispersion
as compare to one dimension.
• Spectral interference eliminated by
echelle grating.
54. • Spectral interference eliminated by
echelle grating.
• Special camera attach to instrument and
they provide widespread application of
multi element analysis.
56. 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.
57. • 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.
