Download or read book Laser Desorption ionization Mass Spectrometric LD MS Analysis of Samples of Forensic Interest written by Leah Gilpin Balko and published by . This book was released on 2002 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Desorption ionization Mass Spectrometric Analysis of Methyl Violet written by Donna M. Grim and published by . This book was released on 2002 with total page 210 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 2015-11-09 with total page 287 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 Laser Desorption Ionization Mass Spectrometry for Biological Forensic and Material Analyses written by 鄭宇航 and published by . This book was released on 2020 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applications of LC MS in Toxicology written by Aldo Polettini and published by Pharmaceutical Press. This book was released on 2006 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical toxicologists are involved in the analysis of drugs and poisons in biological samples in different environments. Many scientists in the field of analytical toxicology have adopted LC-MS in their daily work, and this is illustrated by the increasing numbers of research papers published and presented at relevant conferences.
Download or read book Applications of Mass Spectrometry for the Provision of Forensic Intelligence State of the art and Perspectives written by Simona Francese and published by Royal Society of Chemistry. This book was released on 2023-12-20 with total page 322 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 Laser Desorption Ionisation of Forensically Significant Samples An Investigation Into Low Mass Analysis written by Rachel West and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Forensically significant samples, such as drugs and propellants can be analysed using a range of standard techniques like Hight Performance Liquid Chromatography (HPLC) and Gas Chromatography Mass Spectrometry (GCMS). These methods can often be time-consuming, require complex sample preparation or extraction, with multiple steps and additional components. The drug samples investigated are those that have been inlaid in fibres, in this form to either mimic oral fluid based roadside drug tests or drug laden clothing and other fabrics used in smuggling cases. The analysis of these samples is important and can be complicated by the need for extraction of the analytes from the fibres and the possible destruction of evidence required to perform said analysis. -- Laser Desorption Ionization (LDI) techniques are an intriguing alternative to these standard techniques as they can perform high throughput analysis with little sample preparation and often generate simple spectra. LDI is highly sensitive and specific and is compatible with less stable sample-types. -- The initial issue for LDI analysis of drug samples was associated with low mass interference experienced when such low mass analytes encounter similar mass matrices. Several alternatives to traditional matrices were explored, and it was successfully overcome for on-plate and fibre-based analyses using a layer of gold nanomaterials which provided increased laser absorption without the low mass interference. -- LDI was also explored as a method of analysing complex propellant samples. Propellants contain several different species, which vary among manufacturers and as samples age. They often require multiple techniques for their analysis with different sample preparation techniques. LDI was compared to standard techniques as well as some more interesting alternatives, to successfully differentiate several diverse propellant samples.
Download or read book Laser Induced Breakdown Spectroscopy in Biological Forensic and Materials Sciences written by Gábor Galbács and published by Springer Nature. This book was released on 2022-12-13 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive overview of recent advances in the area of laser-induced breakdown spectroscopy (LIBS), focusing on its application to biological, forensic and materials sciences. LIBS, which was previously mainly used by physicists, chemists and in the industry, has now become a very useful tool with great potential in these other fields as well. LIBS has a unique set of characteristics including minimal destructiveness, remote sensing capabilities, potential portability, extremely high information content, trace analytical sensitivity and high throughput. With its content divided into two main parts, this book provides not only an introduction to the analytical capabilities and methodology, but also an overview of the results of recent applications in the above fields. The application-oriented, multidisciplinary approach of this work is also reflected in the diversity of the expert contributors. Given its breadth, this book will appeal to students, researchers and professionals interested in solving analytical/diagnostic/material characterization tasks with the application of LIBS.
Download or read book The Detection of Ink Dyes by Laser Desorption Mass Spectrometry Coupled with Thin layer Chromatography and the Use of Photochemisty i e Photochemistry for Dye Characterization written by Jamie D. Dunn and published by . This book was released on 2004 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ambient Ionization Mass Spectrometry for the Forensic Screening of Pharmaceuticals and the Determination of Potential Drug Candidates written by Leonard Nyadong and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ambient mass spectrometry (MS) is a new and growing sub-field in MS which has opened new research avenues, particularly for applications relating to the analysis of solid samples. Results on the implementation and application of ambient MS techniques including: desorption electrospray ionization (DESI) and direct analysis in real time (DART) indicated that these techniques could serve as complementary tools for the rapid qualitative screening of pharmaceuticals, allowing up to two orders of magnitude improvement in throughput compared to traditional methods such as liquid chromatography MS. The selectivity of DESI could be enhanced by performing the experiment in the reactive mode. In this mode, complexation reactions between reagents added to the spray solvent and analytes on the sample surface resulted in analyte stabilization, inhibiting fragmentation. They also resulted in a concomitant enhancement in the analyte surface activity, facilitating their evaporation from secondary droplets culminating in an improvement in sensitivity. Also for drug tablets analysis, the analyte signal dependency on DESI geometrical set-up variables could be mitigated following the careful and controlled addition of an isotopically labeled internal standard (IS) to the sample or by spraying samples with a pair of reagents with different affinities for the analyte. Either of these approaches resulted in an analyte-to-IS signal ratio (in the former) or an analyte complex ratio (in the later), which was largely independent of DESI experimental variables allowing quantitative analysis using this technique. DESI MS was also observed to be a very powerful tool for determining the 2-D distribution of various pharmaceutically important compounds on tablet and tissue surfaces. The ability to map the distribution of molecules of interest by DESI MS has very great implications in drug tablet quality control and in determining the role of chemical signals presented on tissue surfaces. DESI was observed to be limited to ionizing molecules of medium to high polarities without much limitation in terms of mass range, whereas DART was better suited for the analysis of molecules within a broader range of polarities, but within a more limited mass range (up to 800 Da approximately). These limitations were circumvented by implementing a novel multimode ambient ion source, desorption electrospray/metastable-induced ionization (DEMI), which combines various aspects of DESI and DART. Initial experiments with the DEMI ion source demonstrated its ability to enable the simultaneous analysis of molecules within a broader range of polarities and masses than DESI and DART alone.
Download or read book Evaluation of Desorption Ionization Mass Spectrometric Methods in the Forensic Applications of the Analysis of Inks on Paper written by DM. Grim and published by . This book was released on 2001 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fast atom bombardment and laser desorption mass spectrometry (LDMS) provide molecular level information concerning an ink's composition. Two ink-jet printer inks, Ink A containing the cationic dye Methyl Violet 2B, and Ink B containing the anionic dye, Solvent Black, were studied. Both positive and negative ion detection modes of the mass spectrometer were used. LD may be used for the analysis of inks on paper. Once on paper, the ink's solvent system has evaporated, leaving mainly the dyes behind, which are detected using LDMS. An ink fades with time, indicating that the dyes are degrading. Preliminary results from an accelerated aging study of ballpoint pen ink using UV irradiation confirm that dye degradation products are formed. The degradation chemistry follows an oxidative demethylation process for which all products formed are detected using LDMS. Results suggest that LDMS may be developed to determine the relative age of inks.
Download or read book Absolute Quantitative Matrix assisted Laser Desorption ionization Mass Spectrometry and Imaging Mass Spectrometry of Pharmaceutical Drugs from Biological Specimens written by Chad Walter Chumbley and published by . This book was released on 2016 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Desorption Mass Spectrometry for High Throughput DNA Analysis and Its Applications written by and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser desorption mass spectrometry (LDMS) has been developed for DNA sequencing, disease diagnosis, and DNA Fingerprinting for forensic applications. With LDMS, the speed of DNA analysis can be much faster than conventional gel electrophoresis. No dye or radioactive tagging to DNA segments for detection is needed. LDMS is emerging as a new alternative technology for DNA analysis.
Download or read book Fundamentals of MALDI ToF MS Analysis written by Samira Hosseini and published by Springer. This book was released on 2016-08-18 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the fundamentals and applications of Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-ToF-MS) technique. It highlights the basic principles, the history of invention as well as the mechanism of ionization and mass determination using this technique. It describes the fundamental principles and methods for MALDI spectra interpretation and determination of exact chemical structures from experimental data. This book guides the reader through the interpretation of MALDI data where complex macromolecular spectra are simplified in order to present the major principles behind data interpretation. In addition, each chapter describes how MALDI-ToF-MS analysis provides necessary understanding of the copolymer systems that have been designed for specialized biomedical applications.
Download or read book Analysis of Complex Biological Mixtures by Matrix assisted Laser Desorption ionization Mass Spectrometry written by Xiaoli Liang and published by . This book was released on 1997 with total page 318 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:
