Development and Characterization of Two Versions of a New Single Particle Mass Spectrometer for Organic Aerosol Analysis that Incorporate a 3D Ion Trap
Development and Characterization of Two Versions of a New Single Particle Mass Spectrometer for Organic Aerosol Analysis that Incorporate a 3D Ion Trap

Author:

Publisher:

Published: 2001

Total Pages:

ISBN-13:

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Aerosol particles are ubiquitous throughout the atmosphere and play an important role in human health, climate, and the chemistry of the atmosphere. A significant mass fraction of these particles is composed of organic species, which remain poorly characterized due to the number and diversity of species present. This thesis describes the development and characterization of two versions of a new single particle mass spectrometer with a 3D ion trap for organic aerosol studies. Version I combines CO2 laser desorption and electron impact ionization in an ion trap. Mass spectra obtained for four species are comparable to NIST EI spectra. Tandem mass spectrometry studies are also demonstrated. The effects of vaporization energy, ionization delay time, and electron pulse width on the mass spectra and fragmentation patterns are examined. The detection limit of the instrument is found to be ~1x108 molecules (350 nm diameter particle) for 2,4-dihydroxybenzoic acid. Version II integrates CO2 laser desorption and tunable VUV ionization in an ion trap and was used for a detailed study of oleyl alcohol, oleic acid and mixtures thereof. Both the degree of fragmentation in the mass spectra and the translational energy of the vaporized molecules are found to vary as a function of desorption energy in the pure particles and as a function of composition in the mixed particles. These changes can be described by the energy absorbed per particle during desorption. We show that these effects hinder the quantitative response of the instrument and have important implications for other two step laser desorption/ionization systems. The final part of this thesis presents preliminary results from atmospherically relevant particles. Mass spectra of cigarette sidestream smoke, fulvic acid, meat cooking, and ammonium bisulfate aerosols are collected using both versions of the instrument. The two step desorption/ionization process only worked for two types of aerosols, while CO2 only mass spectra w.

Mass Spectrometry in Medicinal Chemistry
Mass Spectrometry in Medicinal Chemistry

Author: Klaus Wanner

Publisher: John Wiley & Sons

Published: 2007-06-27

Total Pages: 460

ISBN-13: 352761091X

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This first overview of mass spectrometry-based pharmaceutical analysis is the key to improved high-throughput drug screening, rational drug design and analysis of multiple ligand-target interactions. The ready reference opens with a general introduction to the use of mass spectrometry in pharmaceutical screening, followed by a detailed description of recently developed analytical systems for use in the pharmaceutical laboratory. Applications range from simple binding assays to complex screens of biological activity and systems containing multiple targets or ligands -- all highly relevant techniques in the early stages in drug discovery, from target characterization to hit and lead finding.

Signal Variation in Single Particle Aerosol Mass Spectrometry
Signal Variation in Single Particle Aerosol Mass Spectrometry

Author: Zachary Daniel Wissner-Gross

Publisher:

Published: 2007

Total Pages: 34

ISBN-13:

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Rapid and accurate detection of airborne micro-particles is currently an important problem in national security. One approach to such detection, bioaerosol mass spectrometry (BAMS), is currently under development at Lawrence Livermore National Laboratory. BAMS is a type of single particle aerosol mass spectrometry that rapidly records dual-polarity mass spectra of aerosolized micro-particles. However, the accuracy of the BAMS system is limited by various uncertainties, resulting in shot-to-shot variations in the mass spectra. I found that the variations in mass peak areas in BAMS spectra were significantly larger than those predicted by Poisson statistics based on the mean number of detected ions. Furthermore, these variations were surprisingly consistent as a function of peak area among synthetic, organic, and biological samples. For both positive and negative ions, the standard deviation in a peak's area was approximately proportional to the mean value of that area to the 0.9 power. Using the consistency of this data, I also developed a novel method for quantitatively evaluating the similarity between mass spectra using a chi-square factor. Peak area variations in other single particle aerosol mass spectrometers may be similarly analyzed and used to improve methods for rapid particle identification.

Mass Spectrometry
Mass Spectrometry

Author: Edmond de Hoffmann

Publisher: Wiley

Published: 2001-10-10

Total Pages: 420

ISBN-13: 9780471485650

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Offers a complete overview of the principles, theories and key applications of modern mass spectrometry in this introductory textbook. Following on from the highly successful first edition, this edition is extensively updated including new techniques and applications. All instrumental aspects of mass spectrometry are clearly and concisely described; sources, analysers and detectors. * Revised and updated * Numerous examples and illustrations are combined with a series of exercises to help encourage student understanding * Includes biological applications, which have been significantly expanded and updated * Also includes coverage of ESI and MALDI

Introduction to Mass Spectrometry
Introduction to Mass Spectrometry

Author: J. Throck Watson

Publisher: John Wiley & Sons

Published: 2013-07-09

Total Pages: 972

ISBN-13: 1118681584

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Completely revised and updated, this text provides an easy-to-read guide to the concept of mass spectrometry and demonstrates its potential and limitations. Written by internationally recognised experts and utilising "real life" examples of analyses and applications, the book presents real cases of qualitative and quantitative applications of mass spectrometry. Unlike other mass spectrometry texts, this comprehensive reference provides systematic descriptions of the various types of mass analysers and ionisation, along with corresponding strategies for interpretation of data. The book concludes with a comprehensive 3000 references. This multi-disciplined text covers the fundamentals as well as recent advance in this topic, providing need-to-know information for researchers in many disciplines including pharmaceutical, environmental and biomedical analysis who are utilizing mass spectrometry

Novel Techniques and Applications in Single Particle Mass Spectrometry
Novel Techniques and Applications in Single Particle Mass Spectrometry

Author: John Francis Cahill

Publisher:

Published: 2014

Total Pages: 419

ISBN-13: 9781321232462

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In the environment, aerosol particles can affect climate directly though scattering and absorbing radiation and indirectly by influencing cloud formation, albedo, and lifetime. Beyond the environment, aerosols are commonly used as a delivery mechanism for a variety of products, such as inhalers and spray paints. Chemically characterizing aerosols is a difficult endeavor, and relatively few instrumental methods are capable of doing so. A unique subset of instrumentation and techniques exist to measure aerosol chemical and physical properties. Among these, the aerosol time-of-flight mass spectrometer (ATOFMS) can measure single particle chemistry and size in real time. The ATOFMS was developed for the study atmospheric aerosols, and data acquired by the ATOFMS over the years since its creation has provided significant insight into many atmospheric phenomena; however, the application of this technique into disciplines other than atmospheric chemistry has been relatively unexplored. In this dissertation the ATOFMS is used in a conventional sense, to provide insight into atmospheric particle chemistry through two field studies in California, but also in an unconventional way by using the ATOFMS to answer outstanding questions in other disciplines, including nanomaterials and biochemistry. Often the chemistry of a single unit, rather than of the bulk, is needed in these disciplines, and the ATOFMS is uniquely suited to provide this information. The ATOFMS was used to chemically characterize single particles of a unique class of nanomaterials, called metal organic frameworks (MOFs), comprised of functionalized organic linkers and metal ions or metal ion clusters. ATOFMS data was able to show the presence of MOFs with mixed functionality, and show the exchange of functional groups between materials. Cell processes can be monitored by measuring small molecules that are part of cell metabolism, which can provide insight into cell functions, environment, and disease. Using an ATOFMS with a modified aerodynamic lens inlet, single microalgae cells 4-10 μm in diameter of various types have been be characterized. Compared to other single cell mass spectrometry techniques, the modified ATOFMS has unprecedented throughput, up to 50 Hz. Time-resolved measurements of cells undergoing nitrogen deprivation further highlight the abilities of the technique for single cell analysis.