Download or read book Design Construction and Development of a Laser Desorption Ionization laser Ablation Time of flight Mass Spectrometer for Chemical Analysis with and Without Surface Plasmon Resonance written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 834 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 Investigating the Instrumentational Components of Laser Electrospray Mass Spectrometry written by Rachel Parise and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical method validation is the process of establishing that an analytical technique is applicable for a proposed objective. Early in the method development of a new analytical technique an understanding of the instrumental components and procedures is elaborated through scientifically based optimization. The optimization experiments are used to define the operational parameters that yield the maximum performance by the analytical technique for the target analyte before commencing validation studies. This dissertation details method development through experimental investigations instrumental components of LEMS (substrate, laser parameters, and electrospray source conditions). Each instrumental component has a number of induvial parameters which are optimized to yield the maximum laser electrospray mass spectrometry (LEMS) signal intensity for a given analytical problem. LEMS uses a nonresonant, femtosecond (fs) laser to ablate analytes from a surface. Those ablated analytes are then captured by a perpendicular electrospray, ionized, and desolvated to produce ions which travel into the inlet of the mass spectrometer for analysis. Each element of the LEMS experimental setup works in a complementary fashion to generate a mass spectral signal which have specific optimization steps that can dramatically impact the data that can be acquired. The results of the optimization for each instrumental component will then be applied to preliminary method development experiments for the analysis of pharmaceutical compounds from complex formulations biomarker discovery for mice afflicted with a traumatic brain injury.The effect of the laser pulse duration on the ablation mechanism and amount of laser induced conformational changes of aqueous myoglobin was investigated using 55 fs, 56 picosecond (ps), and 10 nanosecond (ns) pulses and laser pulse energies from 0.05 to 1.6 mJ. It was found that the optical properties of the substrates (stainless-steel and quartz) and laser intensity regimes accessible by each pulse duration determined the amount of myoglobin ablated and subsequent mass spectral signal intensity. Laser ablation of myoglobin from both substrates using all laser pulse energies was observed for the 55 fs pulse while the 10 ns pulse required minimum pulse energies of 0.4 and 1.2 mJ for ablation of myoglobin to occur from stainless-steel and quartz, respectively. As the pulse duration increases, thermal processes increase which dictated the relative amount of protein unfolding, number of phosphate adducts, and degree of solvent adduction. Many of the common laser electrospray ionization (ESI) hybrid techniques employ ns pulse durations. However, the amount of ablated myoglobin originating from a ns pulse was observed to be dependent on the amount of energy that was absorbed by the substrate or sample. Experiments to increase the signal intensity while implementing ns laser electrospray mass spectrometry (ns-LEMS) were performed by exploiting the optical properties of nanomaterials as a potential matrix for desorption and detection of myoglobin. To estimate the contribution of the surface plasmon resonance (SPR) to the desorption of myoglobin under the different pulse duration regimes, the addition of an aqueous gold nanostar (GNS) matrix was implemented. GNSs have a SPR maximum of ~750 nm which overlaps strongly with the 780 nm laser wavelength. Gold nanospheres, which have a SPR of ~530 nm, have an absorption overlap 25 times less than that of the nanostars with the 785 nm laser light and therefore were chosen as a control gold nanoparticle matrix. It was observed that protein mixed with solution phase GNSs improved the laser ablation and consequent mass spectral signal intensity of the protein in comparison to both the nanosphere addition and ablation from quartz without nanomaterial addition for the 55 fs, 56 ps, and 10 ns pulses. This dissertation also extends to an investigation of the electrospray source and the roles that the nebulizing gas pressure, electrospray solution flow rate, and needle protrusion from the emitter sheath effects the electrospray analyte signal and stability. Interactions between the electrospray droplets and nebulizing gas were elucidated using an ablation chamber in which laser ablated analytes were carried via the nebulizing gas flow through the nebulizer sheath to interact with the electrospray Taylor cone, jet, and subsequent droplets. The signal intensity and relative standard deviation (RSD) of an infused Victoria blue solution was used to assess conventional ESI optimization experiments while a mixture of Gly-Gly-His, lactose, adenosine, and vitamin B12 was laser ablated within the ablation chamber for the optimization of the remote ablation device. It was found that a needle protrusion flush with the nebulizing sheath wall, 9 psi nebulizing gas pressure, and 9 μL/min ESI flow rate yielded the highest signal intensity for low and high mass analytes when utilizing the ablation chamber. However, the conventional ESI signal and stability was maximized using a needle protrusion of 0.6 mm from the sheath, 18 psi nebulizing gas pressure, and 9 μL/ min ESI flow rate. The last two chapters describe collaborative efforts with GlaxoSmithKline (GSK) and Temple University's Lewis Katz School of Medicine with the application of LEMS to real world problems. The first of these chapters explores the preliminary method development results for sampling protocols of LEMS in a pathway to measuring the active ingredient in a formulation when differences in concentration are a percent or less for GSK. The results from the method development and optimization experiments in the previous chapters were applied to the GSK pharmaceutical manufacturing paradigm to test product quality in-line and in real-time instead of testing in a lab at the end of the manufacturing process. The LEMS sampling protocols involved ablation of either powder, compressed form, or solution containing powder using laser ablation. The ablated material was then entrained in an electrospray aerosol and transferred into a mass spectrometer for quantitative measurement of the molecules making up the powder, pill, or solution. Measurement time was on the order of seconds so that thousands of samples can be potentially measured in an hour. Future prospective experiments include additional optimization of the solution phase and compressed form sampling methods and, ultimately, the method validation of LEMS for quantifying active ingredients in pharmaceutical formulations. The last chapter seeks to develop new methods to map all biomarkers in traumatic brain injury (TBI) through mass spectrometry imaging (MSI), serum analysis, and protein derivatization assays. In this work, the Ramirez laboratory employs the controlled cortical impact model of experimental TBI in mice, harvests the brain (post injury) and prepares sections for analytical analysis. TBI is a complex injury involving multiple physiological and biochemical alterations to tissue. The potentially thousands of relevant biomarkers spread over a volume of thousands of mm3 makes the spatially resolved chemical analysis of brain a big data problem to which principal component analysis is applied.

Download or read book Construction and Evaluation of a Pulsed Glow Discharge Time of Flight Mass Spectrometer for Real Time Chemical Speciation Analysis and for Direct Solid Sampling Using Laser Ablation written by Daniel Jan Fliegel and published by . This book was released on 2007 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Performance Evaluation of a High Mass Resolution Time of Flight Laser Ablation Ionisation Mass Spectrometer written by Reto Wiesendanger and published by . This book was released on 2019 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: Mass Spectrometry ; Instrument Development ; High Resolution ; Time of Flight ; Laser Ablation ; Solid Sample ; Analytical Chemistry ; Surface Analysis ; Space Research.

Download or read book Development and Application of Two step Laser Desorption multiphoton Ionization Mass Spectrometry written by Jong Hoon Hahn and published by . This book was released on 1988 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Development of Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry and Its Application to the Study of Polymers and Biopolymers written by Sajid Bashir and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directory of Graduate Research written by and published by . This book was released on 2001 with total page 1846 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faculties, publications and doctoral theses in departments or divisions of chemistry, chemical engineering, biochemistry and pharmaceutical and/or medicinal chemistry at universities in the United States and Canada.

Download or read book Construction of a Digitally Operated Aerosol Laser Ablation Ion Trap Time of Flight Mass Spectrometer written by Nathan Michael Hoffman and published by . This book was released on 2017 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital mass spectrometry offers the promise of unlimited mass range and enhanced functionality with existing instrument designs. The theoretical fundamentals of ion handling with digital waveforms have been well-established in the literature. Unfortunately, the lack of practical methods of implementing this theory is corroborated by the lack of publications describing analyses performed using digital mass spectrometry. The work contained herein describes methods of digital ion handling, the digital manipulation of ion stability, methods of controlling digital mass spectrometers, and digital waveform generation using microcontroller-based systems. The trapping of ions produced by laser ablation of aerosol particles is characterized as a function of various ion trap operating parameters. Three methods of low-voltage waveform generation providing a wide range of duty cycle resolution are discussed. The use of microcontrollers and analog-to-digital conversion for data acquisition is also covered in detail. Digital mass spectrometry is poised to expand the mass range of analysis by providing more capable instrumentation at lower cost than is achievable with current sinusoidal waveform technology. This work provides detailed descriptions of the practical methods by which this transition to digital mass spectrometry will be implemented down to the level of microcontroller firmware and hardware schematics.

Download or read book The Development of a Matrix assisted Laser Desorption chemical Ionisation Time of flight Mass Spectrometer written by Christopher Paul Myatt and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamental Studies of Matrix assisted Laser Desorption ionization Time of flight Mass Spectrometry MALDI TOF MS and Its Applications to the Analysis of Biological Materials written by Yongdong Zhu and published by . This book was released on 1999 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies on Surface Assisted Laser Desorption Ionization and Its Analytical Application in Imaging Mass Spectrometry written by Ho-Wai Tang and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Studies on surface-assisted laser desorption/ionization and its analytical application in imaging mass spectrometry" by Ho-wai, Tang, 鄧浩維, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS) is an analytical technique enabling direct chemical analysis of solid samples. Analytes could be desorbed/ionized upon nitrogen laser irradiation from a SALDI substrate-coated sample, then analyzed by MS. The substrate is involved in the transfer of laser energy to the analytes, and eventually assists the desorption/ionization of analytes. The analytical performance of SALDI-MS, such as detection sensitivity, is dependent on different parameters of the substrate, such as size, morphology and form. In this thesis, the effects of several substrate parameters on the SALDI process were investigated. SALDI-MS based Imaging Mass Spectrometry (IMS) method was also developed using efficient SALDI substrate identified in the fundamental studies. IMS is a chemical-specific mapping technique which allows parallel mapping of multiple analytes in solid samples. The desorption mechanism of SALDI is investigated using two groups of substrate, the carbon allotropes and the noble metal nanoparticles. Ion desorption efficiency and internal energy transfer were probed and correlated in carbon-based SALDI. It was found that the ion desorption efficiency and internal energy transfer was in opposite order. Substrate that transferred more internal energy to ions did not show higher ion desorption efficiency. This result could not be explained by the Thermal Desorption model which was a generally believed mechanism of the SALDI desorption process. A non-thermal model, the Phase Transition model is proposed to account for the SALDI desorption process. The Phase Transition model suggests that the substrate is melted/ restructured upon laser irradiation, and this will assist ion desorption. The Phase Transition model is supported by the morphological change of carbon substrates after SALDI and high initial velocity of ions desorbed by carbon-based SALDI (> 1,000 ms-1). SALDI-MS is useful for small molecule analysis due to the relatively clean background in the low mass region. SALDI-IMS is developed and applied to the imaging of spatial distribution of small molecules in forensic and biological samples. Gold nanoparticles (AuNPs) was selected as the substrate from several other noble metal NPs. A solvent-free method, argon ion sputtering, was employed for coating AuNPs on sample surface prior to SALDI-IMS analysis. Fine details of the samples, such as the fine pattern of latent fingerprints and handwriting on questioned documents can be preserved and imaged reliably by avoiding the use of solvent. Fatty acids, drugs and ink components can be imaged in forensic samples including latent fingerprints, banknotes and checks. The solvent-free SALDI-IMS method was also applied to image the distribution of metabolites in intact animal tissues. Spatial distributions of neurotransmitters, nucleobases and fatty acids can be imaged from mouse brain and tumor tissue sections. DOI: 10.5353/th_b4714555 Subjects: Mass spectrometry Imaging systems

Download or read book Matrix Assisted Laser Desorption ionization Orthogonal Acceleration Time of flight Mass Spectrometry written by David Sean Selby and published by . This book was released on 2002 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Laser Desorption Ionization on a Quadrupole Ion Trap Mass Spectrometer written by Rafael Vargas and published by . This book was released on 2019-05-31 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: laser desorption ionization mass spectrometry Dissertation Discovery Company and University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, "Development of Laser Desorption Ionization on a Quadrupole Ion Trap Mass Spectrometer" by Rafael Roberto Vargas, was obtained from University of Florida and is being sold with permission from the author. A digital copy of this work may also be found in the university's institutional repository, IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.

Download or read book Study of Matrix assisted Laser Desorption ionization Time of Flight Mass Spectrometry for Polymer Analysis written by Hassan Rashidzadeh and published by . This book was released on 1999 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamental Study and Method Development for Surface based Laser Desorption Ionization Imaging Mass Spectrometry written by Qiang Liu and published by . This book was released on 2009 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: machaniam, metabolite, mass spectrometry, imaging mass spectrometry, MS.