Flame Emission Spectroscopy CONTENT: introduction, Principal, Instrumentation.

1. Centre for Health and Applied Science (CHAS),
Ganpat University, Ganpat Vidhyanagar,
Mahesana-Gozaria Highway, Kerva-384012
Gujarat, India.
GUIDED BY:-
Dr. Satish A. Patel
Associate Professor
M.Pharm, Ph.D.
preparedBY:-
Ankitkumar S. Vasoya
Enroll No. -19304591015
Semester - 1
F l a m e E m i s s i o n S p e c t r o s c o p y
1
A
S e m i n a r O n

2. Introductions
General Principle
Instrumentation
1.Burner
2.Mirror
3.Slit System
4.Monochromator
5.Filter
6.Detector
Reference
2
Overview

3.  Flame photometry is a branch of spectroscopy. More accurately
called Flame Atomic Emission Spectroscopy (FES).
 Flame photometry is based on the measurement of intensity of
the light emitted when a metal is introduce into a flame to
identify the element.
 A flame photometry is used to determine the concentration certain
metal ions.
 Particularly – Alkali metals, Alkali earth metals.
3
Introduction

4. 4 General Principle
 When a solution of metallic salt sprayed as fine droplets into a flame.
The heat energy (thermal energy) of the flame the solvent in the
droplets dry, leaving a fine residue. This residue convert into neutral
atoms.
 Due to thermal energy of the flame the neutral atoms are converted to
exited status atoms. As the exited state atoms is not stable and the
exited state atoms return to ground state with the emission of
radiation is in specific wavelength.
 The wavelength of the radiation emitted is specific for every element
and is used to identify the element (Qualitative Analysis).
 The intensity of emitted radiation depends upon the concentration of
the elements (Quantitative Analysis).

5. The basic components are
 Light Source
 Mirror
 Monochromator
 Slit system
 Detector
 Read out device (ROD).
5 Instrumentation
Fuel
Oxidant
Sample

6.  The flame used in the flame photometry must possess the following
Functions:
1. The ability to evaporate the liquid droplets from the sample solution,
resulting in the formation of solid residue.
2. The solid residue resulting in the formation of atoms.
3. Must have the capability to excite the atoms.
4. Cause them to emit radiant energy.
 These processes is controlled by several factors which are summarised as
follows:
i. Type of fuel and oxidant & fuel-oxidant ratio.
ii. Type of solvent
iii. Amount of solvent
iv. Type of burner
6
BURNER

7. Total Consumption Burner
 Fuel and oxidant are hydrogen and oxygen.
 Liquid sample is drawn into the flame from the side
tubing hydrogen and oxygen are entering.
 Both are burning at the top of the burner to produce
the flame.
 As soon as the liquid sample is drawn into the base
of flame, the oxygen aspirates sample solution
leaving a solid residue.
 Atomisation and excitation of the sample then follow.
7
 The name “Total Consumption Burner” is used because all the sample
that enters the capillary tube will enter the flame regardless of droplets
size.
 The flame is noisy and turbulent.
 It can be adjusted by proper control of fuel-to-oxidant ratio.
Capillary Tip Burner Tip
Fuel Intel
Oxygen Intel
Capillary
Total Consumption Butner

8. In this energy type of
burner, aspirated
sample, fuel and
oxidant are
thoroughly mixed
before reaching the
burner opening and
then entering the
flame.
8
Premix Burner
In this burner the gases move in non-turbulent
fashion, in laminar flow.
Fuel
Oxidant
Aspirator
air
Sample
Drain
Flame
Mixing
baffles

9. 9
 Only small portion about 5% of the
sample in the form of small droplets
reaches the flame and is easily
decomposed.
 An efficient atomization of the
sample in the side of the spray
chamber and are drained off.
 95% of the sample be wasted these
by resulting in a loss of sensitive.
However, this lost must be balanced
against the loss of larger droplets.
 The flame produced by premix
burner is non turbulent, noiseless
and stable.

10.  The flame is emits the radiation in all
direction in the space.
 Much of the radius is lost and loss of signal
results.
 In order to maximize the amount of radiation
used in the analysis. A mirror is located
behind the burner to reflect the radiation
back to the entrance late of the
monochromator.
 The mirror is concave and curves as wide a
solid angle from the flame as possible. To get
the best results, hottest and studies part of
the flame.
 This helps reduce flame flicker.
10
Mirror
Concave Mirror

11. 11
Slits
 The exit side slit is placed after a monochromator and allows only a selected
wavelength range to pass through the detector.
 It is necessary if emission line from other components in the flame have a
wavelength similar to those of the emission line of the elements. Translate
must prevent search interfering line from reaching the detector.
 With the best equipment entrance
and exit delete are used before
and after the dispersion element.
 The entrance slit cut out most of
the radiation from the
surrounding area and allows only
the flames radiation and mirror
reflected radiation of the flame to
enter the optical system.

12. 12
Monochromator
 In simple flame photometer, the
monochromator is prism but in
expensive model the grating used as
monochromator.
 Quartz is the material most commonly
used for making prism even through
its dispersive power is less than the
glass.
 The grating monochromator employees
of grating which is essentially a series
of parallel straight line got into a plane
surface.

13. 13
Filter
 In some element, the emission
spectrum contains of few line.
In such cases wide wavelength
range will be allowed to enter
the detector without causing
any serious error.
 In such a situation and optical
filter may be used in place of
the slit and monochromator
system.
 The filter is made from such a
material which is transparent
over narrow spectral range.

14. 14 Detectors
 Device which convert energy into electrical signal that are
displayed on readout devices.
 Radiation coming from the optical system is allowed to fall
on the detector which measure the intensity of radiation
falling on it.
 The detector should be sensitive to radiation of all
wavelength that may be examined.

15. 15
Phototube
 Consists of a evacuated glass
tube with a photocathode and a
collector anode.
 The surface of photocathode is
coated with a layer of elements
like Caesium, Silver Oxide or
mixture of them.
 When radiant energy falls on
photosensitive cathode, electrons
are emitted which are attracted
to anode causing current to flow.

16. 16
Photomultiplier Tube
 The principle employed in this
detectors is that, multiplication
of photoelectrons by secondary
emission of electrons.
 In a vacuum tube, a primary
photo cathode is fixed which
receives radiation from the
sample.
 Some eight to ten dynodes are fixed each with increasing potential
of 75-100 V higher than preceding one.
 Near the last dynode is fixed an anode or electron collector
electrode.
 Photo-multiplier is extremely sensitive to light and is best suited
where weaker / low radiation is received.

17. 17
References
1. Gurdeep R. Chatwal, Sham K. Anand. Flame Photometry and
Flame Infrared Emission (FIRE). Instrument Method of
Chemical Analysis, 5th edition, Himalaya Publishing House:
2018, Pg. 2.367, 2.370-2.375.
2. Dr. S. Ravi Sankar. Flame Photometry. Text bool of
Pharmaceutical Analysis, 4th Edition, Rx Publication, Pg. 26-1,
26-13.
3. Dr. G Vidya Sagar. Flame Photometry. Text book of Instrument
Method of Drug Analysis, PharmaMed Press, – P=275
4. https://lab-training.com/2017/09/26/understanding-of-light-
dispersing-elements-in-a-spectrometer/

18. 18
Thank
You