Flame photometer, History, with spectrum, Principal, component of flame photometer, Operational Procedure, Defect and their Removal

1. Flame Photometer
Flame photometer is a spectroscopic technique for determination of microquanties of
the element.
 It was nearly 125 years back Bunson and Kirchoff invented the flame emission
technique for the qualitative determination of the element “Flame Test”.
 In 1890 a french chemist Govy developed an instrument by using an atomizer for
injection of the solution in the flame.
 In the year 1928, A German Mundegardhn developed an instrument by using
Govy technique of atomizer along with a Photographic plate as detective
component. In this way, he was in a position to estimate 30 element out of the
periodic table by this technique.
 In the year 1939, An American Griggs used filter of photo cell and designed an
instrument in the shape nearly resembling to that which is under use at the present
time in the laboratory.
 In, 1945, Bernes Published data for determination of Na, Ca, K, Mg, S and Li by
the flame photometer.
All the emissions and radiation are grouped together for the sake of convince. All
their wave length (λ) of this table is called as Electromagnetic spectrum. Nearly all
the instrument used today for chemical analysis are based upon any one group of an
(λ)
.
Wavelength is in cm.

2. Hertz:-
A frequency cycle in which No. of time a wavelength itself in one second.
Electromagnetic spectrum:-
 Infra Red:-
Waves are emitted by hot bodies and can be detected by special type of
Photographic plate where as Hertzian cannot detected by Photographic plate.
i. I.R used for detection of organic compound
ii. Detection of rheumatoid arthritis(RA) using infrared imaging.
iii. Keeping the meat Hot.
iv. For the spying Purpose
 Visible Spectrum:-
Waves can be detected by Photographic plate or Cameras. Those can be
produce by artificial or natural illumenous bodies.
 LASER:- Light Amplification Synchronized Emitting Radiation
They are produced by high light intensity upon Ruby stone.
i. cutting glass steel
 Ultra-Violet:-
Are produced by ionization of gazer.
i. Used in calorimeter or spectro photometer for chemical analysis.
ii. Deep calorization of the cloth.
iii. For sterilization purpose
iv. Destruction purpose
 X-Rays:-
Those are produced when the fast moving electron in a vacuum are suddenly
stopped with the result that they can pass through opaque bodies can be detected by
Photographic plates and invisible to human eye.
 Alpha(α), Beta(β), Gemma(γ) Rays:-
Are produced by disintegration of atomic nucleus. They produce heat and their
frequency very high.
i. Used disease control in Seed plant
To observe composition of crystal
Principal of Flame Photometer:-
Working of flame photometer is based upon the the flame radiation
emitted by excitation of the atom. When the atom of an element is introduced into the
flame. It absorb thermal energy from burner and the electron shift from the inner
orbits to the outer orbits. This change is termed as the excitation of the atom by
thermal energy. When the atom moves away from the hottest part of the flame. The
absorbed is given out or released and colour produced are specific Na- Golden yellow,
for K- Purple, for Fe- Green, for Lithium- Pink.
The colour intensity is directly proportioned to the quantity of of the element in
the flame. Higher the Con^, more will be the colour intensity. On the basis of this
color intensity, the quantity will be estimated.

3. Component of Flame Photometer:-
 Atomizer:-
An atomizer consist of 3 inlets; 1st
is for the solution, 2nd
is for the gas
and 3rd
is for O2 or air supply.
The 3 inlets are so arranged that when 3 component; solution, fuel, and
air enter the atomizer and then came out formed a mixture that is called aerosol.
The aerosol is composed of droplets of all sizes and during their
journey toward the the burner aerosol shieks a fan like structure called baffle, where
coarse droplets or droplets of bigger size are retained and only fixer droplet reached to
the burner. In the burner, the solvent evaporate, leaving the solute particle in atomic
form in the burner. These atomic particles then get excited through the thermal energy
and impact coloured radiation to the burner which is monitored on Galvanometer.
Burner :-
For the production of flame different combination of oxidant and fuel can be used
the solution of combination depend upon the nature of atom because, each atom
require different energy for it’s excitation.
 When natural gas is used then the temperature of the burner is 1950 o
C.
 Some times H+
and O2 as fuel and oxidant are used.
 Such an atom like that of Al require 3500 o
C for it’s excitation. This Temperature
cannot be obtained from the ordinary fuel, oxidant combination. There, the
cynogen(CN) gas along with O2 is used.

4.  In certain instrument acetylene (C2H2) gas and Air or O2 is employed for the
production of burner when with air then the temperature is of 2250 o
C and when
with O2 then 2500 o
C. When different fuel of oxidant combination are employed
the burner or atomizer are also reduced accordingly.
 For each combination, there is a separate burner. Therefore, one should be careful
in selecting the fuel and oxidant and it should be A / T the type of the burner
present in the instrument of this is not done, the explosion may occur and damage
even the user.
 Radiation;-
From the burner as well as through a metallic reflector present at the back of
the flame is focused upon a lens called as condensing lens. The whole radiation from
the burner is condensed by the lens. This is like an ordinary convex lens. From the
condensing lens, the light rays passed to fall upon the filter e.g. for Na+
or K+
separate
filters. So it filters the light the radiation after passing filter is purely of the element
under estimation. Then this light is allowed to fall or strike upon the photo sensitive
device i.e. Photocell or Photo tube. Where this radiation is converted into electricity
and reaches to the Galvanometer and some reading is obtained.
Higher the Con^, more will be the radiation or color intensity, In the flame higher will
be the generation of electricity by the Photosensitive device vice versa.
 Operational Procedure of Tube:-
 Connect the instrument first with gas supply line, to the electric point and O2 or
Gas supply.
 Open the gas tap and light the burner.
 Fuel or gas pressure should be adjusted to 2.2 inches of water column that can be
prepared by 100 ml test tube, have a cork fitted in it. Water is filled in it and than
this is connected, to the gas supply line in the center there is an other glass tube as
from have the gas outlet is obtained. At the back of the tube, a paper marked with
inches size, is fitted. When the gas enter into it. The water rise into glass tubing
due to pressure of the tube that should be maintained at height of 2.2” warter
column in the tube.

5.  Then switch on the oxidant or O2 supply source.
 The pressure in this case should be maintained at 10lbs sq. Per inch.
 Non-luminous flame should be produced.
 If there is some difficulty in the adjustment of non-luminous flame. The gas and
air supply should be re-adjusted to get the desired flame.
 Feed the distilled water at 5 min. In beginning so that if any residue from the
previous determination is present within the system is wasted away.
 This heaps the atomizer and other component clean for the next sample.
 Record the reading and make calculation accordingly.
 After stopping the analysis, first of all cut off gas supply, the switch off electric
connection finally O2 or Air supply.
Defects and their Removal;-
1) The burner with prolonged use deteriorate and required flame is not produced.
Then, it should be replaced with new one
2) The flame should be non-luminous in nature. If, the flame is spotted then the air
supply filter should be cleaned. This happen due to the presence of the dust
particle in the air which reaches to the burner through the lamp.
3) If the reading does not come within the scale of the instrument the the solutuin
should be diluted.

6. 4) Burner flame goes off when the aerosol is introduced into the flame. The chamber
attached with atomizer is filled with the waste solution when the drain is not
properly open condition. They should be cheeked. The waste solution should
flow regularly through the chain tube.
5) The Galvanometer fitted with instrument is of two types.
i. Needle Type
ii. Suspension wire Type
And no needle is present in this case. A light spot marks upon the scale and act as
a needle. If there Galvanometer is present, it should be protected from physical
jerks. Instrument should be placed in level solid undisturbed surface.
6) If the instrument contain Photocell, it should not be placed under the overhead
light directly in the laboratory.
7) With the passage of time Cr cks appear in the coloured layer of the filter. Such∝
a filter should be rejected.
8) Always keep the metallic reflector and the other application system i.e the lens in
clean condition otherwise the reading for lower concentration will not be
obtained.
9) Before stopping the work always run the instrument for five minute ON or
another system or aerosol system.
10) Whenever it is required to replace the Photocell, do not expose the new photocell
to excessive natural or artificial light, such act can damage the sensitivity of the
photocell.