Atomic absorption spectroscopy

3.  Syed Sheraz Ali Shah (01-161142-106)
 Zeeshan Ahmad (01-161142-067)
 Talha Abbasi (01-161142-058)
 Muhammad Abdullah (01-161141-026)
 Zain Naeem (01-161132-060)
 Nabeel Salamat (01-161142-095)
 Waseem Rasool (01-161141-063)

4.  The technique was introduced in 1955 by
Alan Walsh in Australia ( 1916 – 1998 ).
 The first commercial atomic absorption
spectrometer was introduced in 1959.

5.  Atomic absorption spectroscopy (AAS) is a
spectroanalytical procedure for the
quantitative determination of chemical
elements using the absorption of optical
radiation (light) by free atoms in the gaseous
state.
 A technique for determining the
concentration of particular metal elements in
a sample.

6.  Atomic Absorption Spectroscopy is a very
common technique for detecting metals and
metalloids in samples.
 It is very reliable and simple to use.
 It also measures the concentration of metals
in the sample.
 It can analyze over 62 elements.

7.  Elements detectable by atomic absorption are
highlighted in pink color in periodic table.

9.  Light source
 Nebulizer
 Atomizer
 Monochromators
 Detector
 Read out device

10.  The analyzed sample must contain the reduced
metal in the atomic vaporized state. Commonly,
this is done by using the heat of a flame to break
the chemical bonds and form free, unexcited
atoms.
 Atomic absorption spectroscopy is based on the
principle that when a beam of electromagnetic
radiation is passed through a substance, the
radiation may either be absorbed or transmitted
depending upon the wavelength of the radiation.

11.  The absorption of radiation would bring
about an increase in the energy of the
molecule. The energy gained by the molecule
is directly proportional to the wavelength of
radiation.
The increase in the energy of the molecule
leads to the electronic excitations where
electrons jump to higher energy levels.

12.  Hollow cathode lamp are the most common
radiation source in AAS.
 It contain a tungsten anode and hollow
cylindrical cathode made of the element to be
determined.
 These are sealed in a glass tube with an inert
gas (neon or argon).

14.  Suck up liquid samples at controlled rate.
 Mix the aerosol and fuel and oxidant
thoroughly for introduction into flames.

15. Element to be analyzes to be in atomic state.
Atomization is separation of particles into
individual molecules and breaking molecules
into atoms.
Two types of Atomizer.
 Flame atomizer.
 Graphite tube atomizer.

16.  To create flame, we need to mix an oxidant
gas and a fuel gas. Liquid or dissolve samples
are typically used with flame atomizer.

17.  Uses a graphite coated furnace to vaporize
the sample. The graphite tubes are heated
using a high current power supply.

18.  This is very important part in an atomic
absorption spectrometer.
 A monochromator is used to select
wavelength of light which is absorbed by
sample and to execute other wavelengths.

19.  The light selected by the monochromator is
directed onto a detector, typically a
photomultiplier tube, whose function is to
convert the light signal into an electrical
signal proportional to the light intensity.

21.  https://www.youtube.com/watch?v=_KZjb9G
3hB8

22.  A calibration curve is used to determine the
unknown concentration of an element.
 The instrument is calibrated using several
solutions of known concentrations and a
calibration curve is produced. The calibration
curve shows the concentration against the
amount of radiation absorbed.

23.  The absorbance of standard solutions with a
range of concentrations is measured and
plotted on a graph to obtain a calibration
curve.

27.  The detection limits achievable for individual
elements are important in determining the
usefulness of an analytical technique for a
given analytical problem.

29.  Determination of even small amount of
metals (lead, mercury, calcium and
magnesium).
 Environmental studies: drinking water, ocean
water, soil.
 Food industry, food analysis.
 Used in Industrial raw material.
 Used in pharmaceutical industry.
 Geological analysis

30.  Biological analysis
 Analysis of soil.
 Petroleum Industry
 Mining

31.  Accuracy
 Sensitivity
 Cost
 Accessibility

32.  Lack of versatility
 Equipment
 Precision

33. Atomic absorption spectroscopy is a
spectroanalytical procedure for the
quantitative determination of chemical
elements using the absorption of optical
radiation (light) by free atoms in the gaseous
state. It can also be used to identify the trace
element in soil samples, water etc. The
concentration of unknown element is find by
plotting and using the calibration curve.

34.  http://www1.lasalle.edu/~prushan/Intrumental%20A
nalysis_files/AA-
Perkin%20Elmer%20guide%20to%20all!.pdf
 https://lincolnparkhs.org/ourpages/auto/2010/9/26
/37121222/Chapter%2006%20-
%20Atomic%20Absorption%20Spectroscopy.pdf
 http://www.liskeard.cornwall.sch.uk/images/Liskeard
-Sixth-Form/Atomic-Absorption-Spectrometry.pdf
 https://www.slideshare.net/sharmasuriti/atomic-
absorption-spectroscopy-15185397