Flame photometry/Flame Emission Spectroscopy (FES)/Atomic emission spectroscopy (AES)
156.1 هزار بار بازدید -
6 سال پیش
-
Describes the principle, working and
Describes the principle, working and instrumentation of Flame photometry, Flame emission spectroscopy. It lists out the applications of flame photometry. The complete instrumentation which includes flame atomiser, monochromator, detector, metre and it's role is explained. It also describes how to determine the unknown concentration of alkali (NaCl) and alkaline metals such as sodium using a calibration graph.
Flame Photometry/
Flame Emission Spectroscopy (FEM)
You will be able to
elucidate the principle of Flame photometry.
explain the instrumentation and working of Flame photometry.
list out the applications of Flame photometry.
Emission of light of its own characteristic wavelength by alkali and alkaline earth metals when passed through the flame and the correlation of its emission intensity with the concentration of the element is flame photometry or flame emission spectroscopy.
Solvent gets vapourised leaving behind the solid residue.
The solid residue gets vapourised due to high temperature of the flame and the molecules dissociate to atoms.
The metal atoms are vapourised by the flame and are thermally excited to higher energy level.
The excited metal atom returns to the ground state by emitting light of its own characteristic wavelength. (Na- 589nm, Li670nm, Ca 622 nm, Ba-554nm)
Burner– Air and fuel combines in the burner to produce the flame.
Nebuliser and mixing chamber – Converts the liquid sample to mist and sprays the fine particles into the flame using the compressed jet of gases (fuel and air).
Monochromator/Filter – Allows only the chosen wavelength and absorbs all the other wavelengths. e.g. prism, diffraction grating etc.
Detector – It detects the intensity of the emitted light coming out of the slit and generates current proportional to it. eg. Photocell/photodiode.
Meter- It displays the intensity of the emitted light (higher the concentration higher is the intensity of emitted light higher the meter reading.
The wavelength is fixed at 589nm using the monochromator.
The blank sample is sprayed over the flame and the meter reading is set to zero.
Now the series of standard samples of known concentrations are sprayed one by one and the meter readings are noted.
determination of the unknown concentration using Calibration graph
The calibration graph is plotted with the concentration against intensity of emitted light (meter reading).
The sample of unknown concentration (Cu) is sprayed over the flame and the intensity of emitted light (Eu) (meter reading) is noted.
From the calibration graph the unknown concentration (Cu) can be found .
Applications of Flame photometry
Presence of alkali and alkaline earth metals in water such as Na, K, Ca, Mg etc. can be determined.
Can determine the presence of Na and K in glass melt.
Presence of certain metals in cement samples.
Presence of Na, K and Ca in blood serum. urine samples etc.
Presence of alkali and alkaline earth metals in metallurgical products , catalyst, alloys, high pure metals etc..
Analysis of exchangeable cations in soils.
Flame Photometry/
Flame Emission Spectroscopy (FEM)
You will be able to
elucidate the principle of Flame photometry.
explain the instrumentation and working of Flame photometry.
list out the applications of Flame photometry.
Emission of light of its own characteristic wavelength by alkali and alkaline earth metals when passed through the flame and the correlation of its emission intensity with the concentration of the element is flame photometry or flame emission spectroscopy.
Solvent gets vapourised leaving behind the solid residue.
The solid residue gets vapourised due to high temperature of the flame and the molecules dissociate to atoms.
The metal atoms are vapourised by the flame and are thermally excited to higher energy level.
The excited metal atom returns to the ground state by emitting light of its own characteristic wavelength. (Na- 589nm, Li
Burner– Air and fuel combines in the burner to produce the flame.
Nebuliser and mixing chamber – Converts the liquid sample to mist and sprays the fine particles into the flame using the compressed jet of gases (fuel and air).
Monochromator/Filter – Allows only the chosen wavelength and absorbs all the other wavelengths. e.g. prism, diffraction grating etc.
Detector – It detects the intensity of the emitted light coming out of the slit and generates current proportional to it. eg. Photocell/photodiode.
Meter- It displays the intensity of the emitted light (higher the concentration higher is the intensity of emitted light higher the meter reading.
The wavelength is fixed at 589nm using the monochromator.
The blank sample is sprayed over the flame and the meter reading is set to zero.
Now the series of standard samples of known concentrations are sprayed one by one and the meter readings are noted.
determination of the unknown concentration using Calibration graph
The calibration graph is plotted with the concentration against intensity of emitted light (meter reading).
The sample of unknown concentration (Cu) is sprayed over the flame and the intensity of emitted light (Eu) (meter reading) is noted.
From the calibration graph the unknown concentration (Cu) can be found .
Applications of Flame photometry
Presence of alkali and alkaline earth metals in water such as Na, K, Ca, Mg etc. can be determined.
Can determine the presence of Na and K in glass melt.
Presence of certain metals in cement samples.
Presence of Na, K and Ca in blood serum. urine samples etc.
Presence of alkali and alkaline earth metals in metallurgical products , catalyst, alloys, high pure metals etc..
Analysis of exchangeable cations in soils.
6 سال پیش
در تاریخ 1397/11/27 منتشر شده
است.
156,197
بـار بازدید شده