INTRODUCTION PRINCIPLE INSTRUMENTATION LIMITATIONS APPLICATION

1. MODERN PHARMACEUTICAL ANALYTICAL
TECHNIQUES
Submitted by:
B.Mamatha
M.Pharmacy 1-1
Pharmaceutical Analysis

2. INTRODUCTION:
 Flame photometry more accurately called Flame Atomic
Emission Spectrometry.
 A flame photometer is an instrument used to determine the
concentration of certain metal ions among them sodium,
potassium, calcium and lithium.
 Flame photometry is based on measurement of intensity of the
light emitted when a metal is introduced into flame.

3. PRINCIPLE:
 When a solution of metallic salt is sprayed as fine droplets into
a flame. Due to heat of the flame, the droplets dry leaving a
fine residue of salt. This fine residue converts into neutral
atoms.
 Due to the thermal energy of the flame, the atoms get excited
and there after return to ground state. In this process of return
to ground state, exited atoms emit radiation of specific
wavelength. This wavelength of radiation emitted is specific
for every element.
 The wavelength of color tells what the element is (qualitative)
 The color's intensity tells us how much of the element
present (quantitative).

6.  Under constant and controlled condition ,the light intensity of
the characteristic wave length produced by each of the element
is directly proportional to the number of atoms that are emitting
energy, which in turn is directly proportional to the
concentration of substances of interest in the sample.
 Various metals emits a characteristic color of light when
heated.

8. INSTRUMENTATION
NEBULIZER:
This is the component of sample delivery system. which breaks
up the bigger liquid droplet to smaller liquid droplets.
The process of conversion of sample to mist of finely divided
droplets using a jet of compressed gas is known as
Nebulization.

9. Types of Nebulizer:
There are two types of Nebulizer:
1. Pneumatic Nebulizer
2. Ultrasonic Nebulizer
1. Pneumatic nebulizer sucks the liquid sample in the flow of
high pressure gas and break into small drops when strikes the
glass bead.

10. 2. Ultrasonic nebulizer:
An ultrasonic nebulizer is a small portable device that uses
ultrasonic sound waves to break liquid particles down into a fog
on that they can inhaled easily.

11. ZONE OF FLAME

12. REQUIREMENTS OF FLAME :
 It should have proper temperature.
 Temperature should remain constant throughout the operation.
 There should not be any fluctuation during burning.
FUNCTION OF FLAME
 To convert the analyte of the liquid sample into vapor state.
 To decompose the analyte into atoms and simple molecules.
 To excite the formed atoms/free atoms/simple molecules to
emit radiant energy.

13. MECKER BURNER
 This burner was used earlier and
employed natural gas and
oxygen. Produces relatively low
temp. and low excitation
energies. This are best used for
ALKALI metals only. Now-a-
days it is not used.

14. TOTAL CONSUMPTION BURNER
 In this burner fuel and
oxidant are hydrogen and
oxygen gases. Sample
solution is aspirated through
a capillary by high pressure
of fuel and Oxidant and burnt
at the tip of burner. Entire
sample is consumed.

15. FUEL OXIDANT TEMPERATURE 0C
Natural gas Air 1700-1900
Natural gas Oxygen 2700-2800
Hydrogen Air 2000-2100
Hydrogen Oxygen 2550-2700
Acetylene Air 2100-2400
Acetylene Oxygen 3050-3150
Acetylene Nitrous oxide 2600-2800

16. MIRRORS
 The radiation from the
flame is emitted in all the
directions in space. Much
of the radiation is lost and
loss of signal results. A
mirror is located behind
the burner to reflect the
radiation back to the
entrance slit of the
monochromator. The
reflecting surface of the
mirror is front-faced.

17. SLITS
 The entrance and exit slits are
used before and after the
dispersion elements.
 The entrance slit cuts off most if
radiation from the surroundings
and allows only the radiation
from the flame and the mirror
reflection of flame to enter the
optical system. The exit slit is
placed after the monochromator
and allows only the selected
wavelength range to pass
through the detector.

18. DETECTORS
 PHOTO MULTIPLIER TUBE:
 The photomultiplier (PM) tube detects and amplifies radiant
energy.
 Incident light strikes the coated cathode, emitting electrons.
The electrons are attracted to a series of anodes, known as
dynodes, each having a successively higher positive voltage
These dynodes are of a material that gives off many secondary
electrons when hit by single electrons. Initial electron emission
at the cathode triggers a multiple cascade of electrons within
the PM tube itself. Because of this amplification, the PM tube
is 200 times more sensitive than the phototube.

19.  PM tubes are used in instruments designed to be extremely
sensitive to very low light levels and light flashes of very short
duration.

20. LIMITATIONS
 Limited number of elements that can be analyzed.
 The sample requires to be introduced as solution into fine
droplets. Many metallic salts, soil, plant and other compounds
are insoluble in common solvents. Hence, they can’t be
analyzed by this method.
 Since sample is volatilized, if small amount of sample is
present, it is tough to analyze by this method. As some of it
gets wasted by vaporization.
 Further during solubilization with solvents, other impurities
might mix up with sample and may lead to errors in the spectra
observed.

21. APPLICATIONS
 To estimate sodium, potassium, calcium, lithium etc.,
level in sample of serum, urine, CSF and other body
fluids.
 Flame photometry is used for the determination of
alkali and alkaline earth metals.
 Used in determination of lead in petrol.
 Used in the study of equilibrium constants involving
in ion exchange resins.
 Used in determination of calcium and magnesium in
cement.