Real-time Mass Spectrometric Monitoring of Chemical Processes

Real-time Mass Spectrometric Monitoring of Chemical Processes PDF Author: Isaac Obeng Omari
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Reactions can be monitored in real-time or off-line for qualitative and quantitative information on reaction systems under study. The work presented in this dissertation was focused on the application of reaction monitoring techniques by means of electrospray ionization mass spectrometry (ESI-MS), and ultraviolet-visible (UV-Vis) spectroscopy to solve various problems. For example, in a complex petroleum matrix, naphthenic acids were selectively derivatized using a charge-tagging technique and all the acid derivatives were identified by tandem electrospray ionization mass spectrometry (ESI-MS/MS). To understand the increased visibility of analytes profiled with charge-tagged reagents in ESI-MS, ESI response of permanently charged analytes of different sizes and structures were examined. It turned out that factors, such as the analyte structure, molecular weight and solvent could influence the signal strength of analytes. In a separate study on the effect of magnesium (Mg2+) on Maillard reaction, ESI-MS was used to characterize reaction species, and it was found through UV-Vis spectroscopy that, magnesium can accelerate Maillard chemistry in a dose-dependent manner. ESI-MS was also employed to investigate hydrolysis of aryltrifluoroborates in real-time complemented by pH analysis, whereby a dynamic series of equilibria for numerous ions was determined. As well, by using ESI-MS for on-line reaction monitoring, reaction intermediates of a palladium-catalyzed cyclization reaction of carbamates, and an acid-catalyzed cyclization reaction of benzoxazine were identified. Furthermore, to ensure uniform stirring in reactions conducted simultaneously, a 3D printed circular vial holder enabled standardized stirring conditions in ten vials; and ESI-MS revealed data reproducibility could be achieved through the standardized stirring conditions offered by the vial holder. In a nutshell, the findings given provide practical considerations, and some insights into fundamental ESI-MS science.

Real-time Mass Spectrometric Monitoring of Chemical Processes

Real-time Mass Spectrometric Monitoring of Chemical Processes PDF Author: Isaac Obeng Omari
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Reactions can be monitored in real-time or off-line for qualitative and quantitative information on reaction systems under study. The work presented in this dissertation was focused on the application of reaction monitoring techniques by means of electrospray ionization mass spectrometry (ESI-MS), and ultraviolet-visible (UV-Vis) spectroscopy to solve various problems. For example, in a complex petroleum matrix, naphthenic acids were selectively derivatized using a charge-tagging technique and all the acid derivatives were identified by tandem electrospray ionization mass spectrometry (ESI-MS/MS). To understand the increased visibility of analytes profiled with charge-tagged reagents in ESI-MS, ESI response of permanently charged analytes of different sizes and structures were examined. It turned out that factors, such as the analyte structure, molecular weight and solvent could influence the signal strength of analytes. In a separate study on the effect of magnesium (Mg2+) on Maillard reaction, ESI-MS was used to characterize reaction species, and it was found through UV-Vis spectroscopy that, magnesium can accelerate Maillard chemistry in a dose-dependent manner. ESI-MS was also employed to investigate hydrolysis of aryltrifluoroborates in real-time complemented by pH analysis, whereby a dynamic series of equilibria for numerous ions was determined. As well, by using ESI-MS for on-line reaction monitoring, reaction intermediates of a palladium-catalyzed cyclization reaction of carbamates, and an acid-catalyzed cyclization reaction of benzoxazine were identified. Furthermore, to ensure uniform stirring in reactions conducted simultaneously, a 3D printed circular vial holder enabled standardized stirring conditions in ten vials; and ESI-MS revealed data reproducibility could be achieved through the standardized stirring conditions offered by the vial holder. In a nutshell, the findings given provide practical considerations, and some insights into fundamental ESI-MS science.

Time-Resolved Mass Spectrometry

Time-Resolved Mass Spectrometry PDF Author: Pawel L. Urban
Publisher: John Wiley & Sons
ISBN: 1118887344
Category : Science
Languages : en
Pages : 376

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Book Description
Time is an important factor in physical and natural sciences. It characterizes the progress of chemical and biochemical processes. Mass spectrometry provides the means to study molecular structures by detecting gas-phase ions with the unique mass-to-charge ratios. Time-resolved mass spectrometry (TRMS) allows one to differentiate between chemical states that can be observed sequentially at different time points. Real-time mass spectrometric monitoring enables recording data continuously with a specified temporal resolution. The TRMS approaches – introduced during the past few decades – have shown temporal resolutions ranging from hours down to microseconds and beyond. This text covers the key aspects of TRMS. It introduces ion sources, mass analyzers, and interfaces utilized in time-resolved measurements; discusses the influence of data acquisition and treatment; finally, it reviews most prominent applications of TRMS – in the studies of reaction kinetics and mechanism, physicochemical phenomena, protein structure dynamics, biocatalysis, and metabolic profiling. It will assist science and engineering students to gain a basic understanding of the TRMS concept, and to recognize its usefulness. In addition, it may benefit scientists who conduct molecular studies in the areas of chemistry, physics and biology.

Reactive Intermediates

Reactive Intermediates PDF Author: Leonardo S. Santos
Publisher: John Wiley & Sons
ISBN: 9783527628735
Category : Science
Languages : en
Pages : 341

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Book Description
During the last two decades there has been considerable growth in the development of electrospray ionization mass spectrometry (ESI-MS) as a practical method in the study of reaction mechanisms. This method allows the interception and characterization of key intermediates, either as transient species or as protonated/deprotonated forms of neutral species by API-MS. The outstanding features and advantages of ESI-MS make it one of the most suitable tools for the fast screening of intermediates directly from solution, providing hitherto unavailable chemical information to organic chemists. This monograph provides an overview of the mechanisms involved in ESI-MS, the historical perspectives before looking further in-depth at specific reactions and intermediates. Written by researchers in the field, this book is an unique resource for the understanding of this cutting-edge technique.

Time-resolved Mass Spectrometry

Time-resolved Mass Spectrometry PDF Author: Rafael Goble
Publisher: Createspace Independent Publishing Platform
ISBN: 9781976087998
Category :
Languages : en
Pages : 362

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Book Description
Time is an important factor in physical and natural sciences. It characterizes the progress of chemical and biochemical processes. Mass spectrometry provides the means to study molecular structures by detecting gas-phase ions with the unique mass-to-charge ratios. Time-resolved mass spectrometry (TRMS) allows one to differentiate between chemical states that can be observed sequentially at different time points. Real-time mass spectrometric monitoring enables recording data continuously with a specified temporal resolution.

Direct Analysis in Real Time Mass Spectrometry

Direct Analysis in Real Time Mass Spectrometry PDF Author: Yiyang Dong
Publisher: John Wiley & Sons
ISBN: 3527341846
Category : Science
Languages : en
Pages : 370

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Book Description
Clear, comprehensive, and state of the art, the groundbreaking book on the emerging technology of direct analysis in real time mass spectrometry Written by a noted expert in the field, Direct Analysis in Real Time Mass Spectrometry offers a review of the background and the most recent developments in DART-MS. Invented in 2005, DART-MS offers a wide range of applications for solving numerous analytical problems in various environments, including food science, forensics, and clinical analysis. The text presents an introduction to the history of the technology and includes information on the theoretical background, for exampleon the ionization mechanism. Chapters on sampling and coupling to different types of mass spectrometers are followed by a comprehensive discussion of a broad range of applications. Unlike most other ionization methods, DART does not require laborious sample preparation, as ionization takes place directly on the sample surface. This makes the technique especially attractive for applications in forensics and food science. Comprehensive in scope, this vital text: -Sets the standard on an important and emerging ionization technique -Thoroughly discusses all the relevant aspects from instrumentation to applications -Helps in solving numerous analytical problems in various applications, for example food science, forensics, environmental and clinical analysis -Covers mechanisms, coupling to mass spectrometers, and includes information on challenges and disadvantages of the technique Academics, analytical chemists, pharmaceutical chemists, clinical chemists, forensic scientists, and others will find this illuminating text a must-have resource for understanding the most recent developments in the field.

Mass Spectrometry, Mechanisms, and Molecular Models - Combining Research in Mass Spectrometric Reaction Monitoring and Chemical Education

Mass Spectrometry, Mechanisms, and Molecular Models - Combining Research in Mass Spectrometric Reaction Monitoring and Chemical Education PDF Author: Natalie L. Dean
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This thesis combines work in the areas of mass spectrometric reaction monitoring and chemical education. In the first part of this thesis, real-time mechanistic analysis using electrospray ionization mass spectrometry is reported. In Chapter 1, an introduction to the mass spectrometric instrumentation and methodologies used in this research is provided. In Chapter 2, the real-time mechanistic analysis of the Hiyama cross-coupling reaction using electrospray ionization mass spectrometry is reported, in particular, the fluoride-mediated rearrangement of phenylfluorosilanes that was found to occur even before catalyst addition. Combining Ph3SiF with a fluoride ion source under typical Hiyama cross-coupling conditions causes rapid formation of the expected [Ph3SiF2]-; however, ESI-MS analysis reveals that phenyl-fluoride exchange occurs concomitantly, also producing substantial quantities of [PhnSiF5-n]- (n = 0-2). The exchange process is verified using 19F NMR spectroscopy. This observation may have implications for Hiyama reaction protocols, which use transmetallation from triaryldifluorosilicates as a key step in cross-coupling. Optimization of the methodology used for real-time analysis by ESI-MS to reduce observed contamination from leaching of rubber septa additives is also discussed. In the second part of this thesis, the development and application of two different approaches for generating molecular models for the teaching molecular geometry and VSEPR theory in first year chemistry is reported. Chapter 4 details a method for the application of handheld 3D printing pens for producing models from ABS plastic. In Chapter 5, the development of laser-cut acrylic model kits is detailed, as well as the design and results of a quantitative study aimed at assessing their effectiveness for improving representational competence and comprehension of molecular geometry.

Principles and Applications of Clinical Mass Spectrometry

Principles and Applications of Clinical Mass Spectrometry PDF Author: Nader Rifai
Publisher: Elsevier
ISBN: 0128160640
Category : Science
Languages : en
Pages : 218

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Book Description
Principles and Applications of Clinical Mass Spectrometry: Small Molecules, Peptides, and Pathogens is a concise resource for quick implementation of mass spectrometry methods in clinical laboratory work. Focusing on the practical use of these techniques, the first half of the book covers principles of chromatographic separations, principles and types of mass spectrometers, and sample preparation for analysis; the second half outlines the main applications of this technology within clinical laboratory settings, including determination of small molecules and peptides, as well as pathogen identification. A thorough yet succinct guide to using mass spectrometry technology in the clinical laboratory, Principles and Applications of Clinical Mass Spectrometry: Small Molecules, Peptides, and Pathogens is an essential resource for chemists, pharmaceutical and biotech researchers, certain government agencies, and standardization groups. - Provides concrete examples of the main applications of mass spectrometry technology - Describes current capabilities of the LC- and MS-based analytical methods - Details methods for successful analytical work in the field

Transportable Mass Spectrometry and NMR Instruments for In-situ Chemical Reaction Monitoring and Real Time Analysis

Transportable Mass Spectrometry and NMR Instruments for In-situ Chemical Reaction Monitoring and Real Time Analysis PDF Author: Christopher Alun Whitmore
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Direct Analysis in Real Time Mass Spectrometry

Direct Analysis in Real Time Mass Spectrometry PDF Author: Yiyang Dong
Publisher: John Wiley & Sons
ISBN: 3527803718
Category : Science
Languages : en
Pages : 405

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Book Description
Clear, comprehensive, and state of the art, the groundbreaking book on the emerging technology of direct analysis in real time mass spectrometry Written by a noted expert in the field, Direct Analysis in Real Time Mass Spectrometry offers a review of the background and the most recent developments in DART-MS. Invented in 2005, DART-MS offers a wide range of applications for solving numerous analytical problems in various environments, including food science, forensics, and clinical analysis. The text presents an introduction to the history of the technology and includes information on the theoretical background, for exampleon the ionization mechanism. Chapters on sampling and coupling to different types of mass spectrometers are followed by a comprehensive discussion of a broad range of applications. Unlike most other ionization methods, DART does not require laborious sample preparation, as ionization takes place directly on the sample surface. This makes the technique especially attractive for applications in forensics and food science. Comprehensive in scope, this vital text: -Sets the standard on an important and emerging ionization technique -Thoroughly discusses all the relevant aspects from instrumentation to applications -Helps in solving numerous analytical problems in various applications, for example food science, forensics, environmental and clinical analysis -Covers mechanisms, coupling to mass spectrometers, and includes information on challenges and disadvantages of the technique Academics, analytical chemists, pharmaceutical chemists, clinical chemists, forensic scientists, and others will find this illuminating text a must-have resource for understanding the most recent developments in the field.

Mass Spectrometry for the Analysis of Pesticide Residues and their Metabolites

Mass Spectrometry for the Analysis of Pesticide Residues and their Metabolites PDF Author: Despina Tsipi
Publisher: John Wiley & Sons
ISBN: 1119070007
Category : Science
Languages : en
Pages : 288

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Book Description
Provides an overview of the use of mass spectrometry (MS) for the analysis of pesticide residues and their metabolites. Presents state of the-art MS techniques for the identification of pesticides and their transformation products in food and environment Covers important advances in MS techniques including MS instrumentation and chromatographic separations (e.g. UPLC, HILIC, comprehensive GCxGC) and applications Illustrates the main sample preparation techniques (SPE, QuEChERS, microextraction) used in combination with MS for the analysis of pesticides Describes various established and new ionization techniques as well as the main MS platforms, software tools and mass spectral libraries