EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Further Development and Application of Laser Desorption Ionization  LDI  Using Aerosol Time of flight Mass Spectrometry  ATOFMS

Download or read book Further Development and Application of Laser Desorption Ionization LDI Using Aerosol Time of flight Mass Spectrometry ATOFMS written by Ryan Jay Wenzel and published by . This book was released on 2004 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Desorption Ionization Mass Spectrometry Based on Nanophotonic Structure  From Material Design to Mechanistic Understanding

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.

Book The Development of Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry and Its Application to the Study of Polymers and Biopolymers

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:

Book Matrix free Laser Desorption

Download or read book Matrix free Laser Desorption written by Kai Law and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This project aimed to develop a high throughput, laser based, matrix-free, mass spectrometric technique using nanoporous and nanostructured semiconductor substrates for rapid, sensitive, high resolution and accurate mass analytical approach for complex biological matrices. Laser desorption/ionisation (LDI) based on nanostructured semiconductor surfaces is a novel matrix-free mass spectrometry approach. This novel LDI strategy is closely related to matrix-assisted laser desorption/ionisation (MALDI). However, the functions of the matrix are substituted by an active substrate and the mass spectrum does not suffer matrix interference at the low mass region (m/z below 700). This project aimed to develop this method for pharmaceutical and metabolomic applications, specifically metabolite profiling of complex biological matrices. It was the first time three rival technologies, DIOS, QuickMass and SALDI substrates were evaluated and compared under similar experimental conditions. The study included a comprehensive investigation of the physicochemical properties of these matrix-free LDI substrates, independently from the manufacturers or research group. It also included a comprehensive and detailed mechanistic study and demonstrated the suitability of this novel LDI approach in analysing complex biological mixtures consisting of a hundred or more small biomolecules. It is believed that the physicochemical properties of the substrate have a strong influence on the LDI efficiency. The nature of the substrates was determined by surface analysis and imaging techniques including secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Surface properties that govern the LDI processes were identified. It was found that though pores are not strictly required for ion generation, nano-sized porous structure is an important determinant affecting not only the ionisation efficiency, but also the detection mass range and the longevity of the signal. Although a roughened surface is required for the ion generation, the LDI performance does not depend strongly on the surface roughness, but perhaps more on the thickness, dimension, and density of the surface nanostructures. Micron-sized surface structures do not promote ionisation effectively. Both DIOS and SALDI were found to be silicon based, but the DIOS substrates had been fluoro-silanised. In contrast, the QuickMass substrates were found to be germanium based. The SALDI substrates were found to be oxides passivated. Investigation into surface cleaning technology and chemical modification was carried out on the SALDI substrates. Argon plasma etching followed by fluoro-silane modification was found to be suitable and enhanced the SALDI activity. It was found that fluorine and hydroxyl surface terminations are advantageous. It was proposed that the surface Si-OH moieties are an important proton source and fluorine increases the acidity of the Si-OH moieties. A wide range of biological and pharmaceutical compounds was analysed to determine the compound classes that were amenable to the method. Compounds analysed include amines, amides, amino acids, peptides, saccharides, steroids, lipids and small organic acids. The chemical properties of the compounds were correlated to the mass spectra generated. Laser induced surface reactions were also investigated by SIMS and XPS chemical imaging. It was found that the ionisation process is not a simple acid-base reaction, but a complicated simultaneous multi-reaction similar to that of MALDI. Laser induces further surface oxidation and produces a reduction potential. It was proposed that the energy transfer mechanism is closely linked to the excitation and relaxation dynamics of the exciton and the special surface state of surfaces nanocrystallites. It was also proposed that the entropy of the reaction ultimately determines the ions observed and the rate of reaction determines the selectivity. This proposition departed from the conventional view of aqueous basicities and proton affinities dependence. The analytical characteristics of the DIOS target and MALDI Q-ToF mass spectrometer were investigated. A range of complex biological matrices was analysed, including blood plasma extract, liver extracts, urine extracts, bacterial cells and culture. Extraction methods and the application of principle component analysis (PCA) in the interpretation of the mass spectral data were explored. Suitable extraction methods were found to be important but generally, simplified approaches were sufficient. Even though the RSD value of the ion peaks intensity varied by 10-50%, the application of PCA to the DIOS spectral dataset was still possible.

Book Development and Application of Novel Matrices Under Matrix assisted Laser Desorption ionization Time of flight  MALDI TOF  Mass Spectrometry Conditions

Download or read book Development and Application of Novel Matrices Under Matrix assisted Laser Desorption ionization Time of flight MALDI TOF Mass Spectrometry Conditions written by Bharat R. Mankani and published by . This book was released on 2010 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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

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:

Book Dissertation Abstracts International

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Application of Matrix assisted Laser Desorption ionization Time of flight Mass Spectrometry to the Study of Bacterial Biomolecules

Download or read book Application of Matrix assisted Laser Desorption ionization Time of flight Mass Spectrometry to the Study of Bacterial Biomolecules written by Teresa Catherine Cain and published by . This book was released on 1997 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Exploration of the Quantitative Aspects of Matrix assisted Laser Desorption Ionization Time of flight Mass Spectrometry

Download or read book Exploration of the Quantitative Aspects of Matrix assisted Laser Desorption Ionization Time of flight Mass Spectrometry written by Runbo Li and published by . This book was released on 2013 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advisor: Kevin G. Owens, Ph.D.

Book Development of High sensitivity Atmospheric Pressure  AP  Matrix assisted Laser Desorption ionization  MALDI  and Open Air Ionization Techniques for the Analysis of Biomolecules by Mass Spectrometry

Download or read book Development of High sensitivity Atmospheric Pressure AP Matrix assisted Laser Desorption ionization MALDI and Open Air Ionization Techniques for the Analysis of Biomolecules by Mass Spectrometry written by Arti T. Navare and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Matrix-assisted laser desorption/ionization (MALDI) has been celebrated as a soft ionization method for analyzing very diverse biological species including large proteins, peptides, carbohydrates, lipids and metabolites. The fact that MALDI is tolerant to salts and buffers and that it mostly produces singly charged ions from intact biomolecules is considered highly advantageous over electrospray ionization (ESI). Almost two decades after the introduction of vacuum MALDI, the technique was successfully implemented under atmospheric pressure (AP) conditions by Laiko and co-workers. Some of the most salient advantages of AP-MALDI over vacuum MALDI are its ability to generate intact ions from labile species with minimal fragmentation due to collisional cooling under AP, the ability of performing MSn experiments, and its exchangeability with other ion sources. However, AP-MALDI suffers from limited sensitivity due to low ion transmission efficiency under AP conditions. Because sensitivity is a function of the sample pretreatment method of choice, both preconcentration and selective sample fractionation can be used during the initial stages of the analytical pipeline to improve detectability. To that end, the first part of the work presented in this thesis is aimed at investigating various approaches to improve the sensitivity of AP-MALDI for mass spectrometric analysis of biomolecules. Chapter 1 reviews the history of laser desorption ionization (LDI), presenting salient features of vacuum MALDI and AP-MALDI, and concludes with a brief overview of leading ambient ionization techniques, such as Direct Analysis in Real Time (DART) ionization. Chapter 2 presents an investigation of an on chip sample preconcentration approach coupled to AP-MALDI for high-sensitivity analysis of neuropeptides extracted from Aedes aegypti mosquito heads. The theme of exploring efficient and reproducible purification methods for complex biosamples is continued in Chapter 3, where an evaluation of new on-tip solid-phase extraction (SPE) micro columns with various functional groups is presented. A second approach for enhancing AP-MALDI sensitivity by constructing a new pneumatically-assisted (PA) AP-MALDI ion source is presented in Chapter 4, where various factors affecting the performance of this device are investigated. Chapter 5 describes work involving the evaluation of DART ionization as a high-throughput method for the detection and identification of small terpene molecules central to the Aedes aegypti mosquito lifecycle.

Book Laser Desorption laser Ionization Time of flight Mass Spectrometry Instrument Design and Investigation of the Desorption and Ionization Mechanisms of Matrix assisted Laser Desorption ionization

Download or read book Laser Desorption laser Ionization Time of flight Mass Spectrometry Instrument Design and Investigation of the Desorption and Ionization Mechanisms of Matrix assisted Laser Desorption ionization written by Richard C. King III and published by . This book was released on 1995 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Matrix assisted Laser Desorption Ionization Mass Spectrometry

Download or read book Matrix assisted Laser Desorption Ionization Mass Spectrometry written by Jonathon Kevin Gooden and published by . This book was released on 2005 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Desorption ionization Time of flight Mass Spectrometry of Biomolecules

Download or read book Laser Desorption ionization Time of flight Mass Spectrometry of Biomolecules written by Yu-chen Chang and published by . This book was released on 1996 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: