Download or read book Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Investigation of the Photolysis of Polycyclic Aromatic Hydrocarbons written by Mark J. Dibben and published by . This book was released on 2001-01-01 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the many problems currently being tackled by astrophysicists, two are of particular interest to spectroscopists and molecular physicists. These are emission observed from numerous objects in the infrared region in the interstellar medium and the absorption seen in the near infrared and visible regions. It is generally accepted that the species giving rise to these spectral features are gaseous molecules (or radical or ions), and not dust particles or grains. Polycyclic aromatic hydrocarbons (PAHs) are one class of molecules which have been proposed as carriers of these features. In this dissertation, the effect of visible/UV irradiation on several PAHs is studied in detail. FT-ICR mass spectrometry was used to determine the photolysis products of the ionized PAHs fluorene, naphthalene and 1,2-benzanthracene in the vapor phase by irradiation with a xenon arc lamp. Products of ion-molecule reactions were also characterized for all three PAHs. Broad-band visible and ultraviolet irradiation of ionized fluorene for relatively short times (^0.5s) is shown to lead predominantly to sequential hydrogen atom loss, with one to five hydrogens lost. Rate constants and branching ratios for the photodecomposition of the fluorene parent ion and its dehydrogenated partners have been determined. Longer irradiation times lead to various products resulting from multiple C-C bond cleavages. Density functional calculations are used to show dehydrogenation first occurs from the sp(sup 3) carbon on the five-membered ring and then from only one of the six membered rings. Possible geometries have been calculated for all of the photoproducts. Aggregates are shown to form from the fluorene fragments reacting with neutral molecules. These aggregates are fairly stable except for dehydrogenation and slight acetylene fragmentation. Irradiation of the naphthalene ion for short times resulted in a maximum loss of two hydrogens.

Download or read book Analysis of Biomolecules by Matrix assisted Laser Desorption ionization fourier Transform Mass Spectrometry written by Anissa Wai-Sinn Wong and published by . This book was released on 1998 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in MALDI and Laser Induced Soft Ionization Mass Spectrometry written by Rainer Cramer and published by Springer. This book was released on 2016-08-23 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the state-of-the-art of modern MALDI (matrix-assisted laser desorption/ionization) and its applications. New applications and improvements in the MALDI field such as biotyping, clinical diagnosis, forensic imaging, and ESI-like ion production are covered in detail. Additional topics include MS imaging, biotyping/speciation and large-scale, high-speed MS sample profiling, new methods based on MALDI or MALDI-like sample preparations, and the advantages of ESI to MALDI MS analysis. This is an ideal book for graduate students and researchers in the field of bioanalytical sciences. This book also: • Showcases new techniques and applications in MALDI MS • Demonstrates how MALDI is preferable to ESI (electrospray ionization) • Illustrates the pros and cons associated with biomarker discovery studies in clinical proteomics and the various application areas, such as cancer proteomics

Download or read book Matrix Assisted Laser Desorption Ionization with External Source Quadrupole Fourier Transform Mass Spectrometry for the Analysis of Biomolecules written by Steven Travis Fannin and published by . This book was released on 1995 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Desorption Ionization Mass Spectrometry Based on Nanophotonic Structure From Material Design to Mechanistic Understanding written by Moon-Ju Kim and published by Springer Nature. This book was released on 2023-11-11 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents innovative laser desorption ionization (LDI)-active nanophotonic structures for addressing the challenges that matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) is currently facing and for enhancing LDI efficiency. It presents a variety of cutting-edge nanophotonic structures to satisfy the mass-analytical needs of sensitivity, reproducibility, and quantification. As opposed to the commercialized, conventional organic matrix used in MALDI-MS, these nanostructures are validated to be highly effective in detecting small metabolites and drugs, highlighting their considerable potential in the mass spectrometry field. It also systematically elucidates fundamental LDI processes in terms of the photo-thermal, electronic, and structural characteristics of nanophotonic structures, offering mechanistic knowledge of LDI-MS. Even though LDI-MS performance is heavily influenced by a number of nanostructure parameters, relatively little is known about the LDI processes associated with those characteristics. An in-depth understanding of nanostructure characteristics and LDI mechanisms thus paves the way for more effective, rational design and development of nanostructures with improved LDI capabilities. Further, with a focus on multiple cascades in nanostructure functions in response to laser pulse stimuli, this book provides detailed, step-by-step procedures to design and construct a nanophotonic, LDI-active platform, which may serve as a roadmap for graduate students in the field of mass spectrometry. Readers, including graduate students, researchers, and experts working in the related areas of mass spectrometry, nanophotonics, and material science and material engineering, will find a wealth of useful information in this book.

Download or read book Ion Formation from Organic Solids IFOS III written by Alfred Benninghoven and published by Springer. This book was released on 1986-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 3rd International Conference on Ion Formation from Organic Solids (IFOS III) was held at the University of Munster, September 16-18, 1985. The conference was attended by 60 invited scientists from all over the world. Of the 43 papers which were presented, 40 are included in these proceedings. The aim of IFOS III was to promote the exchange of results and new ideas between scientists actively working in the field of mass spectrometry of involatile materials. Various aspects of the ion formation process - realization and optimization, theoretical understanding and analytical application -were treated, as well as instrumental developments. Some emphasis was placed on recent developments in time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry, and its impact on the mass spectrometry of involatile materials. The most important goal of the conference was to combine facets of the understanding of the most complex ion formation processes with the many different aspects of its analytical application. The participants came from a wide variety of different fields, including pure and applied physics and chemistry, medicine, pharmacy, and space research. Finally, on behalf of all the conference participants, I would like to thank Dr. W. Sichtermann and :\1iss I. Bekemeier for the perfect preparation and technical organization of the conference. The next conference in this series, IFOS IV, is planned for the autumn of 1987, in Munster.

Download or read book Laser Photodissociation and Spectroscopy of Mass separated Biomolecular Ions written by Nicolas C. Polfer and published by Springer Science & Business Media. This book was released on 2013-09-03 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book "Laser photodissociation and spectroscopy of mass-separated biomolecular ions" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. The book describes how the powerful separation capabilities and sensitivity of mass spectrometry (MS) can be combined with the structural insights from spectroscopy by measuring vibrational and electronic spectra of trapped analytes. The implementation of laser-based photodissociation techniques in MS requires basic knowledge of tunable light sources and ion trapping devices. This book introduces the reader to key concepts and approaches in molecular spectroscopy, and the light sources and ion traps employed in such experiments. The power of the methods is demonstrated by spectroscopic interrogation of a range of important biomolecular systems, including peptides, proteins, and saccharides, with laser light in the ultraviolet-visible, and infrared range. The book "Laser photodissociation and spectroscopy of mass-separated biomolecular ions" is an indispensable resource for students and researchers engaged or interested in this emerging field. It provides the solid background of key concepts and technologies for the measurements, discusses state-of-the-art experiments, and provides an outlook on future developments and applications.