1. ATOMIC ABSORPTION SPECTROPHOTOMETRY
FLAME EMISSION SPECTROPHOTOMETRY
Presented by :- Mr. Akash vikal
Presented to :- Dr. Pooja chawla
M.Pharm 1st year
Department :- Pharmaceutics
ISF COLLEGE OF PHARMACY
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2. CONTENTS
• ATOMIC ABSORPTION SPECTROPHOTOMETRY
• FLAME EMISSION SPECTROPHOTOMETRY
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3. ATOMIC ABSORPTION SPECTROPHOTOMETRY is an analyltical
technique that measures the concentration of elements. It
makes use of the absorption of light by these elements in
order to measure their concentration.
Atomic absorption is a very common technique
for detecting metals and metalloids in
environmental samples like aluminium Cu, lead,
Li, Mg, Zn etc.
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4. BASIC PRINCIPLE
Atomic absorption in which the element is not
excited in the flame , but is merely dissociated from
its chemical bond & placed in an unexcited (ground)
state.
Thus the ground state atoms capable of absorbing
radiation In the flame, resulting in decrease in
intensity of the beam from the lamp, The analytical
concentration is determined from the amount of
absorption.
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7. TYPES OF BURNER
There are mainly two types of burners which are
generally used and they are as follows.
1. Total consumption burner
2. Premix/ laminar flow burner
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8. TOTAL CONSUMPTION BURNER
•In this burner fuel and oxidant are
hydrogen and oxygen gases.
Sample solution is aspirated through
a capillary by high pressure of fuel
and oxidant and burnt at the tip of
the burner.
Entire sample is consumed
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9. Laminar/premix flow burner
• In this type of burner
aspirated sample fuel and
oxidant are thoroughly
mixed before reaching
the burner opening and
then entering the flame.
There is high loss of
sample (95%) as large
droplets which are
drained out.
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10. Monochromator
• The monochromator in atomic absorption spectrophotometry is
placed between flame and detector.
• Used to select the specific wavelength of light which is absorbed
by the sample, and to exclude other wavelengths.
• To allow the single line in the spectrum of analyte.
• To minimize the emission from the flame itself because detector
detects photons over a wide wavelength range.
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11. Detector and Read out Device
• The light selected by the
monochromator is directed
onto a detector that is
typically a photomultiplier
tube whose function is to
convert the light signal into
an electrical signal
proportional to the light
intensity.
•The signal could be
displayed for readout, or
further fed into a data station
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12. ATOMIC ABSORPTION
SPECTROPHOTOMETRY APPLICATIONS
There are many applications for atomic absorption:
• Clinical analysis (blood samples: whole blood, plasma,
serum; Ca, Mg, Li, Na, K, Fe).
• Environment analysis: Monitoring our environment- eg:
finding out the levels of various elements in rivers, sea
water, drinking water, air, and petrol.
• Mining: by using Atomic Absorption
Spectrophotometry, the amount of metals such as gold
in rocks can be determined to see whether it is worth
mining the rocks to extract the gold.
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13. ATOMIC ABSORPTION
SPECTROPHOTOMETRY APPLICATIONS
• Trace elements in food analysis.
• Trace element analysis of cosmetics.
• Trace element analysis of hair.
• Analysis of additives in lubricating
oils and greases (Ba, Ca, Na, Li, Zn,
Mg).
• Analysis of soils.
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14. ADVANTAGES AND DISADVANTAGES OF
ATOMIC ABSORPTION
ADVANTAGES DISADVANTAGES
• Inexpensive
•Easy to use
•High precision
• Only solution can be used
•Large samples are needed(1-2
ml)
•Less sensitive than graphic
furnaces standards are not to
achieve due to :- flame
instability
•Variation in composition and
temperature.
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15. FLAME EMISSION SPECTROSCOPY
Flame emission spectroscopy is also an analytical technique that is used to
measure the concentrations of elements in samples.
PRINCIPLE: Atoms of some metals, when given sufficient heat
energy(hot flame) become excited and reemit this energy at wavelengths
characteristics of the element.
• The intensity of radiant energy of characteristic wavelength produced by
the atoms in the flame is directly proportional to the number of atoms
excited in the flame, which in turn is directly proportional to the
concentration of the alkali metal in the sample.
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16. •The excited atoms decay back to lower levels by emitting light.
Emissions are passed through monochromator or filters prior to
detection by photomultiplier tubes.
•Alkali metals are easy to excite by flame.
•Li–red emission.
•Na-yellow emission.
•K-red violet emission.
•Rubidium-red emission.
•Mg-blue emission.
Conti…
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17. Conti…
The instrumentation of flame emission spectroscopy is the same as that of
atomic absorption, but without the presence of a radiation source.
In flame emission, the sample is atomized and the analyte atoms are
excited to highest energy levels, all in the atomizer.
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18. Conti….
• The source of energy in Atomic
Emission could be a flame like the one
used in atomic absorption, or an
inductively coupled plasma (ICP).
• The flame (1700-3150 C) is most useful
for elements with relatively low excitation
energies like sodium, potassium and
calcium.
• The ICP (6000-8000 C) has a very high
temperature and is useful for elements of
high excitation energies.
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19. APPLICATION OF FLAME EMISSION
SPECTROSCOPY
•Electrons of alkali metals like sodium, potassium, lithium become
easily excited hence preferentially analyzed by flame photometry.
•Used in clinical laboratory concentrations of sodium and potassium in
biological fluids like serum, urine and sweat.
•Serum lithium levels- therapeutics monitoring.
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20. COMPARISON BETWEEN ATOMIC ABSORPTION
AND EMISSION SPECTROSCOPY
ABSORPTION EMISSION
Measure trace metal concentrations
in complex matrices.
Atomic absorption depends upon the
number of ground state atoms.
Measure trace metal concentrations
in complex matrices.
Atomic emission depends upon the
number of excited atoms.
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21. ATOMIC ABSORPTION
SPECTROPHOTOMETRY
FLAME EMISSION
SPECTROSCOPY
It measures the radiation absorbed by
the ground state atoms.
Presence of a light source(HCL-
Hollow Cathode Lamp).
The temperature in the atomizer is
adjusted to atomize the analyze atoms
in the ground state only.
It measure the radiation emitted by
the excited atoms.
Absence of the light source.
The temperature in the atomizer is
big enough to atomize the analyte
atoms and excite them to a higher
energy level.
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