logging in or signing up chemical ionization mass spectrometry vkdhakar 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: 2394 Category: Education License: All Rights Reserved Like it (3) Dislike it (0) Added: April 09, 2009 This Presentation is Public Favorites: 1 Presentation Description Chemical Ionization (CI) was introduced by Field and Munson (1966). Their work stemmed from earlier observations that some molecules introduced into an EI source at high pressure would generate ions of the type [M+H]+ rather than the conventional M+ molecular ion. This process, which became known as "self - CI" generated stable molecular species. Comments Posting comment... By: nitinpatelpharma09 (17 month(s) ago) IT IS MU4 MORE KNOWLEDGEBLE.. THANKS TO MR. VINOD KUMAR.. HOW CAN I GET IT BRO.. PLS IF I CAN. Saving..... Post Reply Close Saving..... Edit Comment Close By: ankit_ghildiyal (28 month(s) ago) nice one Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript CHEMICAL IONIZATION MASS SPECTROMETRY [CIMS] : CHEMICAL IONIZATION MASS SPECTROMETRY [CIMS] An Assignment Submitted to Singhania University Towards Partial Fulfilment of Semester-I of Master of Pharmacy Presented By:- Vinod Kumar Dhakar School of Pharmacy & Medical Science Singhania University Pacheri Bari, Jhunjhunu (Raj) 2008 Key Points : Key Points Introduction Need of chemical ionization Chemical Ionization Advantages How it works ? Types of Chemical Ionization References Introduction : Introduction Chemical Ionization (CI) was introduced by Field and Munson (1966). Their work stemmed from earlier observations that some molecules introduced into an EI source at high pressure would generate ions of the type [M+H]+ rather than the conventional M+ molecular ion. This process, which became known as "self - CI" generated stable molecular species. Need of chemical ionization : Need of chemical ionization Spectra generated by electron impact (EI) may suffer from the disadvantages of excessive fragmentation and lack of a molecular ion, problems which can some time be overcome by lowering the electron impact energy that means use of chemical ionization technique. Chemical Ionization : Chemical Ionization Chemical ionization (CI) is an ionization technique used in mass spectrometry. Chemical ionization is a lower energy process than electron ionization. The lower energy yields less fragmentation, and usually simpler spectra. A typical CI spectra has an easily identifiable molecular ion. Advantages : Advantages More abundant peak related to molecular ion. Simpler fragmentation patterns Easy application of gas chromatography-mass spectrometry interfacing. Since methane can be used not only reactant gas but also as the carrier gas in the gas chromatography How it works ? : How it works ? In a CI experiment, ions are produced through the collision of the analyte (sample) with ions of a reagent (or ionizing) gas that are present in the ion source. Some common reagent gases include: methane, ammonia, and isobutane. Inside the ion source, the reagent gas is admitted in several thousand fold excess compared to the analyte (sample). Slide 8: The pressure within the ion chamber is about 1mg Hg (1 Torr). The mixture is subjected to electron bombardment (100eV). Electrons entering the source will preferentially ionize the reagent gas The resultant collisions with other reagent gas molecules will create secondary ions, which in turn interact in a specific manner with molecule of the sample Positive and negative ions of the analyte are formed by reactions with secondary ion. Slide 9: If we consider methane as a typical reagent gas, electron impact first removes an electron from the molecule to give CH4+ & CH3+ (Primary ion ), which is then involved in ion-molecule reaction to yield the secondary ions. Then positive and negative ions of the analyte (sample) are formed by reactions with secondary ions. Slide 10: Steps of chemical ionization 1.Primary Ion Formation CH4+ e -----? CH4+ + 2e CH4+ -----? CH3+ + H. Slide 11: 2.Secondary Reagent Ions CH4+ + CH4 --------? CH5+ + CH3 CH3+ + CH4 --------? C2H5+ + H2 C2H5++ CH4 --------? C3H5 + 2H2 Slide 12: 3.Product ion Formation CH5+ + MH---------? MH2+ + CH4 MH + C2H5+ ------? MH2+ + C2H4 MH + C2H5+ ------? M+ + C2H6 Types of Chemical Ionization : Types of Chemical Ionization Gas phase chemical ionization Negative chemical ionization (NCI) Positive chemical ionization (PCI) Applications : Applications Used in the identification of mixture of drugs in body fluid. Used for the detection of Morphine, related alkaloids and their metabolites in the urine. Used for the investigation of complex mixture of compound, particularly from biological fluids. Used for analysis of drugs from urine in overdose patient. References : References Beckett, A.H., Stenlake J.B.; “Practical Pharmaceutical Chamistry”.fourth edition- part two. Kemp William, “Organic Spectroscopy". Third edition; Palgrave, New York. Silverstein,R.M and Basler, G.C. (1968) “Spectrometric Identification of Organic Compounds”, Wiley, New York. Slide 16: Thank You….. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
chemical ionization mass spectrometry vkdhakar 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: 2394 Category: Education License: All Rights Reserved Like it (3) Dislike it (0) Added: April 09, 2009 This Presentation is Public Favorites: 1 Presentation Description Chemical Ionization (CI) was introduced by Field and Munson (1966). Their work stemmed from earlier observations that some molecules introduced into an EI source at high pressure would generate ions of the type [M+H]+ rather than the conventional M+ molecular ion. This process, which became known as "self - CI" generated stable molecular species. Comments Posting comment... By: nitinpatelpharma09 (17 month(s) ago) IT IS MU4 MORE KNOWLEDGEBLE.. THANKS TO MR. VINOD KUMAR.. HOW CAN I GET IT BRO.. PLS IF I CAN. Saving..... Post Reply Close Saving..... Edit Comment Close By: ankit_ghildiyal (28 month(s) ago) nice one Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript CHEMICAL IONIZATION MASS SPECTROMETRY [CIMS] : CHEMICAL IONIZATION MASS SPECTROMETRY [CIMS] An Assignment Submitted to Singhania University Towards Partial Fulfilment of Semester-I of Master of Pharmacy Presented By:- Vinod Kumar Dhakar School of Pharmacy & Medical Science Singhania University Pacheri Bari, Jhunjhunu (Raj) 2008 Key Points : Key Points Introduction Need of chemical ionization Chemical Ionization Advantages How it works ? Types of Chemical Ionization References Introduction : Introduction Chemical Ionization (CI) was introduced by Field and Munson (1966). Their work stemmed from earlier observations that some molecules introduced into an EI source at high pressure would generate ions of the type [M+H]+ rather than the conventional M+ molecular ion. This process, which became known as "self - CI" generated stable molecular species. Need of chemical ionization : Need of chemical ionization Spectra generated by electron impact (EI) may suffer from the disadvantages of excessive fragmentation and lack of a molecular ion, problems which can some time be overcome by lowering the electron impact energy that means use of chemical ionization technique. Chemical Ionization : Chemical Ionization Chemical ionization (CI) is an ionization technique used in mass spectrometry. Chemical ionization is a lower energy process than electron ionization. The lower energy yields less fragmentation, and usually simpler spectra. A typical CI spectra has an easily identifiable molecular ion. Advantages : Advantages More abundant peak related to molecular ion. Simpler fragmentation patterns Easy application of gas chromatography-mass spectrometry interfacing. Since methane can be used not only reactant gas but also as the carrier gas in the gas chromatography How it works ? : How it works ? In a CI experiment, ions are produced through the collision of the analyte (sample) with ions of a reagent (or ionizing) gas that are present in the ion source. Some common reagent gases include: methane, ammonia, and isobutane. Inside the ion source, the reagent gas is admitted in several thousand fold excess compared to the analyte (sample). Slide 8: The pressure within the ion chamber is about 1mg Hg (1 Torr). The mixture is subjected to electron bombardment (100eV). Electrons entering the source will preferentially ionize the reagent gas The resultant collisions with other reagent gas molecules will create secondary ions, which in turn interact in a specific manner with molecule of the sample Positive and negative ions of the analyte are formed by reactions with secondary ion. Slide 9: If we consider methane as a typical reagent gas, electron impact first removes an electron from the molecule to give CH4+ & CH3+ (Primary ion ), which is then involved in ion-molecule reaction to yield the secondary ions. Then positive and negative ions of the analyte (sample) are formed by reactions with secondary ions. Slide 10: Steps of chemical ionization 1.Primary Ion Formation CH4+ e -----? CH4+ + 2e CH4+ -----? CH3+ + H. Slide 11: 2.Secondary Reagent Ions CH4+ + CH4 --------? CH5+ + CH3 CH3+ + CH4 --------? C2H5+ + H2 C2H5++ CH4 --------? C3H5 + 2H2 Slide 12: 3.Product ion Formation CH5+ + MH---------? MH2+ + CH4 MH + C2H5+ ------? MH2+ + C2H4 MH + C2H5+ ------? M+ + C2H6 Types of Chemical Ionization : Types of Chemical Ionization Gas phase chemical ionization Negative chemical ionization (NCI) Positive chemical ionization (PCI) Applications : Applications Used in the identification of mixture of drugs in body fluid. Used for the detection of Morphine, related alkaloids and their metabolites in the urine. Used for the investigation of complex mixture of compound, particularly from biological fluids. Used for analysis of drugs from urine in overdose patient. References : References Beckett, A.H., Stenlake J.B.; “Practical Pharmaceutical Chamistry”.fourth edition- part two. Kemp William, “Organic Spectroscopy". Third edition; Palgrave, New York. Silverstein,R.M and Basler, G.C. (1968) “Spectrometric Identification of Organic Compounds”, Wiley, New York. Slide 16: Thank You…..