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ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
ATOMIC ABSORPTION SPECTROSCOPY
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ATOMIC ABSORPTION SPECTROSCOPY

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  • 1. ATOMICATOMICABSORPTIONABSORPTIONSPECTROSCOPYSPECTROSCOPYPresented by : MOHAMMED WAQAR SIDDIQUIPresented by : MOHAMMED WAQAR SIDDIQUI
  • 2. CONTENTS:CONTENTS: Principle of AAS.Principle of AAS. Instrumentation.Instrumentation. Applications.Applications. Test perform in AKU.Test perform in AKU.
  • 3. INTRODUCTION:INTRODUCTION: Atomic Absorption Spectroscopy is a very commonAtomic Absorption Spectroscopy is a very commontechnique for detecting metals and metalloids intechnique for detecting metals and metalloids insamples.samples. It is very reliable and simple to use.It is very reliable and simple to use. It can analyze over 62 elements.It can analyze over 62 elements. It also measures the concentration of metals in theIt also measures the concentration of metals in thesample.sample.
  • 4. HISTORY:HISTORY:The first atomic absorption spectrometer was built byThe first atomic absorption spectrometer was built byCSIRO scientist Alan Walsh in 1954. Shown in theCSIRO scientist Alan Walsh in 1954. Shown in thepicture Alan Walsh(left), with a spectrometer.picture Alan Walsh(left), with a spectrometer.
  • 5. Elements detectable by atomic absorption are highlighted in pink in thisElements detectable by atomic absorption are highlighted in pink in thisperiodic tableperiodic table
  • 6. PRINCIPLE:PRINCIPLE: The technique uses basically the principle that freeThe technique uses basically the principle that freeatoms (gas) generated in an atomizer can absorbatoms (gas) generated in an atomizer can absorbradiation at specific frequency.radiation at specific frequency. Atomic-absorption spectroscopy quantifies theAtomic-absorption spectroscopy quantifies theabsorption of ground state atoms in the gaseous state .absorption of ground state atoms in the gaseous state . The atoms absorb ultraviolet or visible light and makeThe atoms absorb ultraviolet or visible light and maketransitions to higher electronic energy levels. The analytetransitions to higher electronic energy levels. The analyteconcentration is determined from the amount ofconcentration is determined from the amount ofabsorption.absorption.
  • 7. - Concentration measurements are usually determined from aConcentration measurements are usually determined from aworking curve after calibrating the instrument with standardsworking curve after calibrating the instrument with standardsof known concentration.of known concentration.- Atomic absorption is a very common technique forAtomic absorption is a very common technique fordetecting metals and metalloids in environmental samplesdetecting metals and metalloids in environmental samples..
  • 8. THEORY:THEORY:DetectorMonochromator AtomizerNebulizerHollow CathodeLampAtomicAbsorptionspectrometer
  • 9. Schematic diagram of AAS:Schematic diagram of AAS:
  • 10. LIGHT SOURCE:LIGHT SOURCE: Hollow Cathode Lamp are the most common radiationHollow Cathode Lamp are the most common radiationsource in AAS.source in AAS. It contains a tungsten anode and a hollow cylindricalIt contains a tungsten anode and a hollow cylindricalcathode made of the element to be determined.cathode made of the element to be determined. These are sealed in a glass tube filled with an inert gasThese are sealed in a glass tube filled with an inert gas(neon or argon ) .(neon or argon ) . Each element has its own unique lamp which must beEach element has its own unique lamp which must beused for that analysis .used for that analysis .          
  • 11. NEBULIZER:NEBULIZER: suck up liquid samples at controlled rate.suck up liquid samples at controlled rate. create a fine aerosol spray for introduction into flame.create a fine aerosol spray for introduction into flame. Mix the aerosol and fuel and oxidant thoroughlyMix the aerosol and fuel and oxidant thoroughlyfor introduction into flame.for introduction into flame.
  • 12. AtomizerAtomizer ElementsElements to be analyzed needs to be in atomic sate.to be analyzed needs to be in atomic sate. AtomizationAtomization isis separation of particles into individualseparation of particles into individualmolecules and breaking molecules into atoms. This ismolecules and breaking molecules into atoms. This isdone by exposing the analyte to high temperatures in adone by exposing the analyte to high temperatures in aflame or graphite furnace .flame or graphite furnace .
  • 13. ATOMIZERS:ATOMIZERS:ATOMIZERFLAMEATOMIZERSGRAPHITE TUBEATOMIZERS
  • 14. FLAME ATOMIZERFLAME ATOMIZER:: To create flame, we need to mix an oxidant gas and aTo create flame, we need to mix an oxidant gas and afuel gas.fuel gas. in most of the cases air-acetylene flame or nitrous oxide-in most of the cases air-acetylene flame or nitrous oxide-acetylene flame is used.acetylene flame is used. liquid or dissolved samples are typically used with flameliquid or dissolved samples are typically used with flameatomizer.atomizer.        
  • 15. GRAPHITE TUBE ATOMIZERGRAPHITE TUBE ATOMIZER:: uses a graphite coated furnace to vaporize the sample.uses a graphite coated furnace to vaporize the sample. ln GFAAS sample, samples are deposited in a smallln GFAAS sample, samples are deposited in a smallgraphite  coated tube which can then be heated tographite  coated tube which can then be heated tovaporize and atomize the analyte.vaporize and atomize the analyte. The graphite tubes are heated using a high currentThe graphite tubes are heated using a high currentpower supply.power supply.
  • 16. MONOCHROMATOR:MONOCHROMATOR: This is a very important part in an AA spectrometer. It isThis is a very important part in an AA spectrometer. It isused to separate out all of the thousands of lines.used to separate out all of the thousands of lines. A monochromator is used to select the specificA monochromator is used to select the specificwavelength of light which is absorbed by the sample,wavelength of light which is absorbed by the sample,and to exclude other wavelengths.and to exclude other wavelengths. The selection of the specific light allows theThe selection of the specific light allows thedetermination of the selected element in the presence ofdetermination of the selected element in the presence ofothers.others.
  • 17. DETECTOR:DETECTOR: The light selected by the monochromator is directed ontoThe light selected by the monochromator is directed ontoa detector that is typically a photomultiplier tube , whosea detector that is typically a photomultiplier tube , whosefunction is to convert the light signal into an electricalfunction is to convert the light signal into an electricalsignal proportional to the light intensity.signal proportional to the light intensity. The processing of electrical signal is fulfilled by a signalThe processing of electrical signal is fulfilled by a signalamplifier . The signal could be displayed for readout , oramplifier . The signal could be displayed for readout , orfurther fed into a data station for printout by thefurther fed into a data station for printout by therequested formatrequested format..
  • 18. Calibration CurveCalibration Curve A calibration curve is used to determine the unknownA calibration curve is used to determine the unknownconcentration of an element in a solution. The instrumentconcentration of an element in a solution. The instrumentis calibrated using several solutions of knownis calibrated using several solutions of knownconcentrations. The absorbance of each known solutionconcentrations. The absorbance of each known solutionis measured and then a calibration curve ofis measured and then a calibration curve ofconcentration vs absorbance is plotted.concentration vs absorbance is plotted. The sample solution is fed into the instrument, and theThe sample solution is fed into the instrument, and theabsorbance of the element in this solution isabsorbance of the element in this solution ismeasured .The unknown concentration of the element ismeasured .The unknown concentration of the element isthen calculated from the calibration curvethen calculated from the calibration curve
  • 19. APPLICATIONS:APPLICATIONS:Determination of even small amounts of metals (lead,Determination of even small amounts of metals (lead,mercury, calcium, magnesium, etc) as follows:mercury, calcium, magnesium, etc) as follows: Environmental studies: drinking water, ocean water, soil.Environmental studies: drinking water, ocean water, soil. Food industry.Food industry. Pharmaceutical industry.Pharmaceutical industry.
  • 20. TEST IN AKUTEST IN AKULEAD COCENTRATION.LEAD COCENTRATION.ZINC COCENTRATION.ZINC COCENTRATION.COPPER COCENTRATION.COPPER COCENTRATION.
  • 21. REFERENCES:REFERENCES: Vogel’s Textbook of Quantitative AnalysisVogel’s Textbook of Quantitative Analysis, G. Svehla,, G. Svehla,Pearson.Pearson. Principles of Instrumental AnalysisPrinciples of Instrumental Analysis, Skoog., Skoog.Basic Concepts Of Analytical chemistryBasic Concepts Of Analytical chemistry, S M Khopkar., S M Khopkar.

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