logging in or signing up 8-Flame Emission Spectroscopy Deokate Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4461 Category: Entertainment License: All Rights Reserved Like it (9) Dislike it (1) Added: July 12, 2010 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: parsa2012 (1 days ago) good Saving..... Post Reply Close Saving..... Edit Comment Close By: Thagunna (9 month(s) ago) It is very good presentation. Please allow me to download. Saving..... Post Reply Close Saving..... Edit Comment Close By: Thagunna (9 month(s) ago) It is a very good ppt. I have gone through it. Please permit me to download it. Saving..... Post Reply Close Saving..... Edit Comment Close By: jwquimix (11 month(s) ago) its a excellent ppt Saving..... Post Reply Close By: Deokate (10 month(s) ago) Thanks Saving..... Edit Comment Close By: ashish18feb (13 month(s) ago) its a very good ppt i want to download it...... ppt permit me to do so.. Saving..... Post Reply Close By: Deokate (10 month(s) ago) Thanks for your review you can see more presentation uploaded on authorstream.com or www.gcopamravati.ac.in on study materaial webpage and you can download from it Saving..... Edit Comment Close loading.... See all Premium member Presentation Transcript Flame Emission Spectroscopy : 1 Flame Emission Spectroscopy U.A. Deokate Lecturer Copyright © by U. A. Deokate, all rights reserved. Introduction : Deokate U.A. 2 17-Nov-06 Introduction Flame photometry, now more properly called flame atomic emission spectrometry, is a relatively old instrumental analysis method. Atomic emission is a fast, simple, and sensitive method for the determination of trace metal ions in solution. Because of the very narrow (ca. 0.01 nm) and characteristic emission lines from the gas-phase atoms in the flame plasma, the method is relatively free of interferences from other elements. The method is suitable for many metallic elements, especially for those metals that are easily excited to higher energy levels at the relatively cool temperatures of typical flames – Na, K, Ca, Rb, Cs, Cu, and Ba. Principle : Deokate U.A. 3 17-Nov-06 Principle It is observed that the characteristic yellow light is emitted by sodium when introduced in to flame. Brightness of flame varies with amount of Na. Sample is dissolved in water or organic solvent. It is introduced in flame by means of atomizer under controlled conditions. [NB atomizer does not convert anything into atoms]. Flame is used to excite the atoms. Principle : Deokate U.A. 4 17-Nov-06 Principle A series of processes occur when a solution containing ion is nebulized through a flame. The solvent get vapourised leaving particle of salt. The salt is subsequently vapourised and dissociated in to atoms. Some of the atoms are vapourised by the flame The excited atoms emit radiation characteristic of their species. Theory : Deokate U.A. 5 17-Nov-06 Theory Sample solution sprayed or aspirated as fine mist into flame. Conversion of sample solution into an aerosol by atomizer (scent spray) principle.No chemical change in the sample in this stage. Heat of the flame vaporizes sample constituents. Still no chemical change. (Solvent vaporizes leaves solid partial of salt) By heat of the flame + action of the reducing gas (fuel), molecules & ions of the sample species are decomposed and reduced to give ATOMS. eg Na+ + e- --> Na Heat of the flame causes excitation of some atoms into higher electronic states. Excited atoms revert to ground state by emission of light energy, of characteristic wavelength; measured by detector. Slide 6: Deokate U.A. 6 17-Nov-06 Flame Emission -> it measures the radiation emitted by the excited atoms that is related to concentration. Atomic Absorption -> it measures the radiation absorbed by the unexcited atoms that are determined. Atomic absorption depends only upon the number of unexcited atoms, the absorption intensity is not directly affected by the temperature of the flame. The flame emission intensity in contrast, being dependent upon the number of excited atoms, is greatly influenced by temperature variations. Relationship Between Atomic Absorption and Flame Emission Spectroscopy Instrumentation: : Deokate U.A. 7 17-Nov-06 Instrumentation: Flame photometer consists of following components: Pressure regulators and flow meters for fuel gases Flame source The atomizing device The optical system Photosensitive detectors Read out unit. Instrumentation: : Deokate U.A. 8 17-Nov-06 Instrumentation: Cell (Flame): is a burner nebuliser system in which fuel and oxidant are feed, mixed and comes out through orifice forming a turbulent flame. Wavelength selectors: May be a filter or Monochromator, entrance and exit slits Detector: Photomultiplier tube. Recorder and readout unit. Block diagram of instrument : Deokate U.A. 9 17-Nov-06 Block diagram of instrument Requirements of flame: : Deokate U.A. 10 17-Nov-06 Requirements of flame: It should have proper temperature Temp. should remain constant throughout operation. There should not be any fluctuation during burning. Function flame includes: To convert the constituent of the liquid sample in to vapor state. To decompose the constituent in to atoms or simple molecules. To electronically excite a fraction of the resulting atomic or molecular spectra. Flame temperature: : Deokate U.A. 11 17-Nov-06 Flame temperature: The optimum flame temp. depends upon several factors as excitation energy of the element, sensitivity of the measurement, Presence of other elements etc. The temp. of fame lies between 1000OC and 3000OC. Mixture of coal gas and air do not give very hot flames, because of presence of nitrogen. The cynogen gas produces excellent spectra but it is toxic. Acetylene and hydrogen are most frequent choice Fuel gas : Deokate U.A. 12 17-Nov-06 Fuel gas Various hydrocarbon gases are satisfactory Ordinary cooking gas: 1700OC Acetylene flame 2000 to 2300OC for Li Mg The functions of an analytical flame spectrometer : Deokate U.A. 13 17-Nov-06 The functions of an analytical flame spectrometer Transformation of the solution to be analyzed into a vapor containing free atoms or molecular compounds of the analyte in the flame; Selection and detection of the optical signal (arising from the analyte vapor) which carries information on the kind and concentration of the analyte; Amplification and read-out of the electrical signal. Transformation of sample into vapour : Deokate U.A. 14 17-Nov-06 Transformation of sample into vapour With a pneumatic nebulizer operated by a compressed gas, the solution is aspirated from the sample container and nebulized into a mist or aerosol of fine droplets. By desolvation, i.e., evaporation of the solvent from the droplets, this mist is converted into a dry aerosol which is volatilized in the flame. The atomization, i.e., the conversion of volatilized analyte into free atoms is performed by the flame or other atomizer. Nebulizers used in flame photometer : Deokate U.A. 15 17-Nov-06 Nebulizers used in flame photometer According to the source of energy used for nebulization as, for example, Pneumatic or ultrasonic nebulizers. According to the way the liquid is taken up, e.g., suction, gravity-fed, controlled flow, and reflux-nebulizers. According to the relative position of the capillaries for the nebulizing gas and the aspirated liquid, e.g., angular and concentric nebulizers. Atomizers: : Deokate U.A. 16 17-Nov-06 Atomizers: Ideal characteristic include Continuous atomization Equal droplet size Sturdy and easily cleaned Types: Which introduces spray directly in to flame Which introducing flame in chamber of atomizer Burners : Deokate U.A. 17 17-Nov-06 Burners Flames are produced by means of a burner to which fuel and oxidant are supplied in the form of gases. With the premix burner, fuel and oxidant are thoroughly mixed inside the burner housing before they leave the burner ports and enter the primary combustion or inner zone of the flame. This type of burner usually produces an approximately laminar flame, and is commonly combined with a separate unit for nebulizing the sample. The direct-injection burner combines the function of nebulizer and burner. Burners used in flame photometry : Deokate U.A. 18 17-Nov-06 Burners used in flame photometry Total Consumption burners Premix burner: Wavelengths of filters : Deokate U.A. 19 17-Nov-06 Wavelengths of filters Element Wave- Length (nm) Calcium 422.7 Lithium 670.8 Potassium 766.5 Sodium 589.0 General tips for flame photometry : Deokate U.A. 20 17-Nov-06 General tips for flame photometry Propane-air or natural gas-air gives good flame - strong heat, minimal background light emission. But always need to run a solvent blank for setting zero emission. Solutions diluted to fall within linear part of emission curve. Can calibrate with standards accordingly (eg from 0.05 - 0.25 mM Na+). Use of very low conc Na+ and K+ solutions ---> problems of avoiding contamination. Especially Na+, leaches slowly from glass, contact with skin. Anion and cation interference effects can cause errors (enhancement or suppression). "Radiation buffer" for dilution of standards and samples to swamp out inconsistencies. Internal standard (lithium) useful to counter random flame instability and random dilution errors Application of flame photometry : Deokate U.A. 21 17-Nov-06 Application of flame photometry Determination of Na+, K+, Ca++,Mg++ in biological fluids. (Serum, plasma & Urine) Analysis of Industrial waste for pollutants Hardness of water You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
8-Flame Emission Spectroscopy Deokate Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4461 Category: Entertainment License: All Rights Reserved Like it (9) Dislike it (1) Added: July 12, 2010 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: parsa2012 (1 days ago) good Saving..... Post Reply Close Saving..... Edit Comment Close By: Thagunna (9 month(s) ago) It is very good presentation. Please allow me to download. Saving..... Post Reply Close Saving..... Edit Comment Close By: Thagunna (9 month(s) ago) It is a very good ppt. I have gone through it. Please permit me to download it. Saving..... Post Reply Close Saving..... Edit Comment Close By: jwquimix (11 month(s) ago) its a excellent ppt Saving..... Post Reply Close By: Deokate (10 month(s) ago) Thanks Saving..... Edit Comment Close By: ashish18feb (13 month(s) ago) its a very good ppt i want to download it...... ppt permit me to do so.. Saving..... Post Reply Close By: Deokate (10 month(s) ago) Thanks for your review you can see more presentation uploaded on authorstream.com or www.gcopamravati.ac.in on study materaial webpage and you can download from it Saving..... Edit Comment Close loading.... See all Premium member Presentation Transcript Flame Emission Spectroscopy : 1 Flame Emission Spectroscopy U.A. Deokate Lecturer Copyright © by U. A. Deokate, all rights reserved. Introduction : Deokate U.A. 2 17-Nov-06 Introduction Flame photometry, now more properly called flame atomic emission spectrometry, is a relatively old instrumental analysis method. Atomic emission is a fast, simple, and sensitive method for the determination of trace metal ions in solution. Because of the very narrow (ca. 0.01 nm) and characteristic emission lines from the gas-phase atoms in the flame plasma, the method is relatively free of interferences from other elements. The method is suitable for many metallic elements, especially for those metals that are easily excited to higher energy levels at the relatively cool temperatures of typical flames – Na, K, Ca, Rb, Cs, Cu, and Ba. Principle : Deokate U.A. 3 17-Nov-06 Principle It is observed that the characteristic yellow light is emitted by sodium when introduced in to flame. Brightness of flame varies with amount of Na. Sample is dissolved in water or organic solvent. It is introduced in flame by means of atomizer under controlled conditions. [NB atomizer does not convert anything into atoms]. Flame is used to excite the atoms. Principle : Deokate U.A. 4 17-Nov-06 Principle A series of processes occur when a solution containing ion is nebulized through a flame. The solvent get vapourised leaving particle of salt. The salt is subsequently vapourised and dissociated in to atoms. Some of the atoms are vapourised by the flame The excited atoms emit radiation characteristic of their species. Theory : Deokate U.A. 5 17-Nov-06 Theory Sample solution sprayed or aspirated as fine mist into flame. Conversion of sample solution into an aerosol by atomizer (scent spray) principle.No chemical change in the sample in this stage. Heat of the flame vaporizes sample constituents. Still no chemical change. (Solvent vaporizes leaves solid partial of salt) By heat of the flame + action of the reducing gas (fuel), molecules & ions of the sample species are decomposed and reduced to give ATOMS. eg Na+ + e- --> Na Heat of the flame causes excitation of some atoms into higher electronic states. Excited atoms revert to ground state by emission of light energy, of characteristic wavelength; measured by detector. Slide 6: Deokate U.A. 6 17-Nov-06 Flame Emission -> it measures the radiation emitted by the excited atoms that is related to concentration. Atomic Absorption -> it measures the radiation absorbed by the unexcited atoms that are determined. Atomic absorption depends only upon the number of unexcited atoms, the absorption intensity is not directly affected by the temperature of the flame. The flame emission intensity in contrast, being dependent upon the number of excited atoms, is greatly influenced by temperature variations. Relationship Between Atomic Absorption and Flame Emission Spectroscopy Instrumentation: : Deokate U.A. 7 17-Nov-06 Instrumentation: Flame photometer consists of following components: Pressure regulators and flow meters for fuel gases Flame source The atomizing device The optical system Photosensitive detectors Read out unit. Instrumentation: : Deokate U.A. 8 17-Nov-06 Instrumentation: Cell (Flame): is a burner nebuliser system in which fuel and oxidant are feed, mixed and comes out through orifice forming a turbulent flame. Wavelength selectors: May be a filter or Monochromator, entrance and exit slits Detector: Photomultiplier tube. Recorder and readout unit. Block diagram of instrument : Deokate U.A. 9 17-Nov-06 Block diagram of instrument Requirements of flame: : Deokate U.A. 10 17-Nov-06 Requirements of flame: It should have proper temperature Temp. should remain constant throughout operation. There should not be any fluctuation during burning. Function flame includes: To convert the constituent of the liquid sample in to vapor state. To decompose the constituent in to atoms or simple molecules. To electronically excite a fraction of the resulting atomic or molecular spectra. Flame temperature: : Deokate U.A. 11 17-Nov-06 Flame temperature: The optimum flame temp. depends upon several factors as excitation energy of the element, sensitivity of the measurement, Presence of other elements etc. The temp. of fame lies between 1000OC and 3000OC. Mixture of coal gas and air do not give very hot flames, because of presence of nitrogen. The cynogen gas produces excellent spectra but it is toxic. Acetylene and hydrogen are most frequent choice Fuel gas : Deokate U.A. 12 17-Nov-06 Fuel gas Various hydrocarbon gases are satisfactory Ordinary cooking gas: 1700OC Acetylene flame 2000 to 2300OC for Li Mg The functions of an analytical flame spectrometer : Deokate U.A. 13 17-Nov-06 The functions of an analytical flame spectrometer Transformation of the solution to be analyzed into a vapor containing free atoms or molecular compounds of the analyte in the flame; Selection and detection of the optical signal (arising from the analyte vapor) which carries information on the kind and concentration of the analyte; Amplification and read-out of the electrical signal. Transformation of sample into vapour : Deokate U.A. 14 17-Nov-06 Transformation of sample into vapour With a pneumatic nebulizer operated by a compressed gas, the solution is aspirated from the sample container and nebulized into a mist or aerosol of fine droplets. By desolvation, i.e., evaporation of the solvent from the droplets, this mist is converted into a dry aerosol which is volatilized in the flame. The atomization, i.e., the conversion of volatilized analyte into free atoms is performed by the flame or other atomizer. Nebulizers used in flame photometer : Deokate U.A. 15 17-Nov-06 Nebulizers used in flame photometer According to the source of energy used for nebulization as, for example, Pneumatic or ultrasonic nebulizers. According to the way the liquid is taken up, e.g., suction, gravity-fed, controlled flow, and reflux-nebulizers. According to the relative position of the capillaries for the nebulizing gas and the aspirated liquid, e.g., angular and concentric nebulizers. Atomizers: : Deokate U.A. 16 17-Nov-06 Atomizers: Ideal characteristic include Continuous atomization Equal droplet size Sturdy and easily cleaned Types: Which introduces spray directly in to flame Which introducing flame in chamber of atomizer Burners : Deokate U.A. 17 17-Nov-06 Burners Flames are produced by means of a burner to which fuel and oxidant are supplied in the form of gases. With the premix burner, fuel and oxidant are thoroughly mixed inside the burner housing before they leave the burner ports and enter the primary combustion or inner zone of the flame. This type of burner usually produces an approximately laminar flame, and is commonly combined with a separate unit for nebulizing the sample. The direct-injection burner combines the function of nebulizer and burner. Burners used in flame photometry : Deokate U.A. 18 17-Nov-06 Burners used in flame photometry Total Consumption burners Premix burner: Wavelengths of filters : Deokate U.A. 19 17-Nov-06 Wavelengths of filters Element Wave- Length (nm) Calcium 422.7 Lithium 670.8 Potassium 766.5 Sodium 589.0 General tips for flame photometry : Deokate U.A. 20 17-Nov-06 General tips for flame photometry Propane-air or natural gas-air gives good flame - strong heat, minimal background light emission. But always need to run a solvent blank for setting zero emission. Solutions diluted to fall within linear part of emission curve. Can calibrate with standards accordingly (eg from 0.05 - 0.25 mM Na+). Use of very low conc Na+ and K+ solutions ---> problems of avoiding contamination. Especially Na+, leaches slowly from glass, contact with skin. Anion and cation interference effects can cause errors (enhancement or suppression). "Radiation buffer" for dilution of standards and samples to swamp out inconsistencies. Internal standard (lithium) useful to counter random flame instability and random dilution errors Application of flame photometry : Deokate U.A. 21 17-Nov-06 Application of flame photometry Determination of Na+, K+, Ca++,Mg++ in biological fluids. (Serum, plasma & Urine) Analysis of Industrial waste for pollutants Hardness of water