This document summarizes a seminar presentation on atomic spectroscopy techniques. It begins with an introduction defining atomic spectroscopy and listing some common techniques. It then describes the basic principles of atomic spectroscopy, how atoms absorb and emit electromagnetic radiation. It provides an overview of the typical instrumentation used, including components like atomizers and spectrometers. Applications are mentioned like analyzing heavy metals in medical or environmental samples. In conclusion, it notes atomic spectroscopy is widely used for elemental analysis and continues to advance with improvements to sensitivity and detection limits.

1. POST GRADUATE DEPARTMENT OF BIOTECHNOLOGY
TERESIAN COLLEGE, MYSORE
SUBJECT : BIOANALYTICALTECHNIQUES
SEMINAR ON :
‘ATOMIC SPECTROSCOPY’
SUMITTED TO :
WILFRED A
ASSISTANT PROFESSOR
POST GRADUATE,
DEPARTMENT OF
BIOTECHNOLOGY
TERESIAN COLLEGE
SUMITTED FROM :
ARPITHA CP
1ST MSC (BIOTECHNOLOGY)
POST GRADUATE, DEPARTMENT OF
BIOTECHNOLOGY
TERESIAN COLLEGE

2. Presentation on :
Atomic
spectroscopy

3. CONTENT :
1)INTRODUCTION
2)PRINCIPLE OF ATOMIC SPECTROSCOPY
3)INSTRUMENTATION
4)WORKING OF ATOMIC SPECTROSCOPY
5)APLLICATIONS OF ATOMIC SPECTROSCOPY
6)CONCLUSION
7)REFERENCE

4. INTRODUCTION :
‘Spectroscopy’ is the study of interactions between matter and different forms of electromagnetic radiation ; when
practiced to quantitative analysis, the term spectrometry is used.
Atomic spectroscopy is the study of the electromagnetic radiation absorbed and emitted by atoms.
Atomic spectroscopy is typically based on the analysis of electromagnetic radiations emitted by the atoms in the
element.
This electromagnetic radiation related to particular atoms ; therefore detection is very accurate even for very small
sample amounts.
Atomic spectroscopy includes the techniques of atomic absorption spectroscopy [AAS], atomic emission spectroscopy
[AES], atomic fluorescence spectroscopy [AFS], X- Ray fluorescence [XRF], and inorganic mass spectroscopy [MS].
AAS, AES, and AFS exploit interactions between UV visible light and the valence electrons of free gaseous atoms.

5. In XRF, high energy charged particles collide with inner shell electrons of atom, initiating transitions with eventual
emission of X-ray.
For inorganic MS ionized analyte atoms are separated in a magnetic field according to their mass to charge [ m/z]
ratio.
In atomic absorption spectroscopy, the light of a predetermined wavelength is passed through a collection of
atoms. If the wavelength of the source of light has energy corresponding to the energy difference between two
energy levels in the atoms, a portion of the light will be absorbed.
The difference between the intensity of the light emitted from the source and the light collected by the detector
yields an absorbance value.
This absorbance value can then be used to determine the concentration of the given element with the sample.
In atomic emission spectroscopy the intensity of the light is directly proportional to the concentration of sample.

6. PRINCIPLE :
Every element has a characteristic atomic structure, with a small positively charged nucleus surrounded by
sufficient number of electrons to maintain neutrality.
Electrons settle into orbitals within an atom and one of the can also jump from one energy to higher energy by
acquiring necessitated energy.
This energy is provided by colliding with other atoms, such as heating- AES, photons derived from light AAS and
AFS on high energy electrons – possible transitions happen, when the required energy reaches to the difference
between two energy states.
 This energy is provided by colliding with other atoms, such as heating AES, photons derived from light AAS and
AFS, on high energy electrons – possible transitions happen, when the required energy reaches to the difference
between two energy states.

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8.  Electrons of the corresponding atoms will be excited as energy is absorbed as a results, the amount of light
transmitted from the system to the detector will be reduced this is understood AAS.
 Under appropriate circumstances outer shell electrons of vaporised atoms may be excited by heating.
 As these electrons return to the more stable ground state, energy is lost. Some of this energy is emitted as
light, which can be measured with a detector, this is AES.

9. INSTRUMENTATION :
 Formation of the atomic vapour is the major principle of emission, absorption and fluorescence technique.
The most critical component of instruments in atomic spectroscopy is the atomization sources and samples
introduction devices with an associated spectrometer for wavelength selection and detection of light.
Atomization involves the several key {the basic} steps: solvent removal, separation from anion and others of the
matrix, and reduction of ions to the ground state atom.
The design of an AFS instrument is similar to those for AAS and AES except that the light source and the
detector are located at a right angle.
A light source which emits the sharp atomic lines of the element to be determined is selected. there are two
types of light sources used in these instruments: continuous sources and line sources.
 A continuous source, also called to as a broad-band source, emits radiation over a broad range of wavelengths.
A line source, on the other hand, emits radiation at specific wavelengths, but this source of radiation is not as
pure as radiation from a laser.

10.  Atomizer is any device which will produce ground state atoms as a vapour into the light path. Many atomizers
utilized for AFS are similar to those used for AAS and AES. The atomizers most commonly used in these
techniques are flames and electro thermal atomizers .
 The flame provides for easy and fast measurements with few interferences and is preferred at any appropriate
concentration for the analyte. Flame atomizers contain a pneumatic nebulizer, an expansion chamber, and an air-
acetylene laminar flame with a 10 cm path length.
Most systems use a graphite tube which is heated electrical energy, a technique called graphite furnace
atomization other materials are sometimes used.
Two major types of wavelength selectors – filters and monochromators. Detectors use sensitive transducer that
converts the signal that comes from light energy into electrons.
Detector produces signal, S in a linear function of the electromagnetic radiations’ power :
{where :
K = detector’s sensitivity ; D = detector’s dark current/ background current when no radiation of source
reached to the detector }
Phototubes and photomultipliers include a photosensitive surface that absorbs radiation in the UV visible or
near IR generatring and electrical current proportional to the no of pjotons reaching the transducer
P S=k P+ D

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7_5/MediaObjects/483925_1_En_5_Fig1_HTML.png

12. WORKING :
◦
Analytical working range can be considered as the concentration range over which quantitative
results can be obtained without recaliberation for system.
◦
Selecting a technique with an analytical working range based on the analyte concentrations
range based on the expected analyte concentrations, minimizes the analysis times by allowing
the samples with different analyte concentrations to be analysed together.

13. APPLICATIONS :
The key principle and application areas of atomic spectroscopy techniques :-
 A medical laboratory could determine the type of heavy metals that could be present in patient’s serum
or urine.
Environmental scientists could scientists could monitor heavy metals contamination of water and soil.
The pharmaceutical industry uses these techniques to determine metals and metalloids in drug.

14. CONCLUSION :
Analytical method of atomic spectroscopy have been used for elemental identification and quantification in
varieties of samples. Recently, most of all the spectroscopic techniques available are used in the analysis of
metals and trace elements in samples of industrial and environmental origin.
Progress continues to develop in analytical spectroscopy as improvements
are made to sensitivity, limits of detections and availability. Recent development depends on instrumental
adjustments and slight modifications to allow new types of measurements. Advancements in material science
have revealed demand for new methods of measurements using instruments already accessible, pushing the
boundaries of what was previously available.

15. REFERENCE :
 Wilson. K and Walker. J (SEVENTH EDITION), Principle techniques of biochemistry and
molecular biology, Cambridge university press (2010).
 https://www.sciencedirect.com/topics/chemistry/atomic – spectroscopy.
 https://en.m.wikipedia.org/wiki/atomic-spectroscopy.

16. THANK YOU……