Atomic Spectroscopy Atomic Absorption and Emission spectroscopy Instrumentation and Principle.

1. By MANZOOR AHMAD BHAT
SEMESTER : 6th
ROLL NO : 42
TEACHER INCHARGE: IMTIYAZ SIR & UZMA MA’AM

2.  Spectroscopy is defined as the study of interaction between EMR &
matter(elements, compounds, etc. ).
 Based on the type of matter that interacts with EMRs, we have 2 classes of
spectroscopies-
1) Atomic Spectroscopy 2) Molecular Spectroscopy
• ATOMIC SPECTROSCOPY :- Spectroscopy involving interaction b/w EMR and
atoms (Or) It is the study of EMR absorbed and emitted by atoms.
• Applications:- I) Used for detecting elements (atoms) in a sample/analyte
(QUALITATIVE ANALYSIS).
II) Also Used for measuring the concentration of a particular
element in a sample(QUANTITATIVE ANALYSIS).

3. • Atomic Spectroscopy has 3 Sub-branches, viz.,
> Atomic Absorption Spectroscopy (AAS)
> Atomic Emission Spectroscopy (AES)
> Atomic Fluorescence Spectroscopy(AFS)
1) ATOMIC ABSORPTION SPECTROSCOPY
This technique uses the principle that free gaseous atoms generated in an atomizer can
absorb radiation at specific wavelength.

4. 2) ATOMIC EMISSION SPECTROSCOPY
• Study of radiations emitted by excited atoms .
• Doesn’t require light source.
• Principle : The sample is atomized & the analyte atoms are excited to higher energy level.
The
excited atoms in the flame emit light that reaches the detector (Photomultiplier tube).
• Emission wavelength & energy are related by
∆E = hc / λ

5. •NOTE : -The instrumentation of AES is same as that of AAS , but without the presence of a
radiation source.
3) ATOMIC FLUORESCENCE SPECTROSCOPY
When a sample is converted to gaseous atoms,the element of interest is excited to a higher
electronic energy level by a light source (UV radiation).
Following excitation,the atoms return to the ground state by the emission of a photon ,& this
emitted radiation is measured.