EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Development of Mass Spectrometric Systems to Analyse the Result of Laser Ablation Experiments on Nano  and Microparticles

Download or read book Development of Mass Spectrometric Systems to Analyse the Result of Laser Ablation Experiments on Nano and Microparticles written by Albert Pegus and published by . This book was released on 2005 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Chemical Characterization of Microparticles by Laser Ablation in an Ion Trap Mass Spectrometer

Download or read book Chemical Characterization of Microparticles by Laser Ablation in an Ion Trap Mass Spectrometer written by and published by . This book was released on 1991 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are developing a new technique for the chemical characterization of microparticles based upon the use of electrodynamic traps. The electrodynamic trap has achieved widespread use in the mass spectrometry community in the form of the ion trap mass spectrometer or quadrupole ion trap. Small macroscopic particles can be confined or levitated within the electrode structure of a three-dimensional quadrupole electrodynamic trap in the same way as fundamental charges or molecular ions by using a combination of ac and dc potentials. Our concept is to use the same electrode structure to perform both microparticle levitation and ion trapping/mass analysis. The microparticle will first be trapped and spatially stabilized within the trap for characterization by optical probes, i.e., absorption, fluorescence, or Raman spectroscopy. After the particle has been optically characterized, it is further characterized using mass spectrometry. Ions are generated from the particle surface using laser ablation or desorption. The characteristics of the applied voltages are changed to trap the ions formed by the laser with the ions subsequently mass analyzed. The work described in this paper focuses on the ability to perform laser desorption experiments on microparticles contained within the ion trap.

Book DESIGN  DEVELOPMENT AND APPLICATION OF ANALYTICAL APPARATUSES FOR LASER ELECTROSPRAY MASS SPECTROMETRY ANALYSIS

Download or read book DESIGN DEVELOPMENT AND APPLICATION OF ANALYTICAL APPARATUSES FOR LASER ELECTROSPRAY MASS SPECTROMETRY ANALYSIS written by Habiballah Sistani and published by . This book was released on 2019 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: With any analytical technique, there are inherent deficiencies that can be improved upon for optimizing sensitivity, ease of analysis, reproducibility, etc. The unifying goal of this work is the design and implementation of apparatuses to improve the capabilities of laser-electrospray hybrid based mass spectrometry techniques, with laser electrospray mass spectrometry (LEMS) serving as the experimental subject for projects discussed in this thesis. In LEMS, ~60 fs laser pulses centered at 800 nm are used to vaporize the analyte from a surface into the gas phase without the need for a matrix. The laser-vaporized analytes are then captured by an electrospray source and detected via a mass spectrometer. The dried droplet technique is the most common method of sample preparation for LEMS analysis where aliquots of sample are deposited onto a substrate followed by drying at room temperature. While the dried droplet technique is convenient, a spatially inhomogeneous distribution of analytes is deposited which results in high laser shot to shot signal variance, consequently resulting in high variances between replicate samples. To increase the homogeneity of the sample deposited, an electrospray deposition (ESD) device was built and used for deposition of samples of Victoria blue on stainless steel or indium tin oxide (ITO) slides. LEMS measurements of the ESD-prepared films on both substrates were comparable and revealed lower average relative standard deviations (RSD) for measurements within-film (20.9%) and between-films (8.7%) in comparison to dried droplets (75.5% and 40.2%, respectively). The mass spectral response for ESD samples on both substrates was linear (R2 > 0.99), enabling quantitative measurements over the selected range of 7.0 × 10−11 to 2.8 × 10−9 mol, as opposed to the dried droplet samples where quantitation was not possible (R2 = 0.56). Another major limitation in all laser-ESI hybrid systems is that the sample must be in close proximity to the mass spectrometer inlet. In order to transfer laser ablated materials via an electrospray source, the electrospray needle must be close enough to the high voltage inlet to produce charge separation, generate a Taylor cone and ultimately, charged droplets. This short distance (on the order of mm) restricts the size and geometry of the samples to be analyzed. This dissertation details the design of a novel remote sampling device for LEMS analysis. The vaporization process takes place inside a controlled gas flow compartment of a sample chamber where a nitrogen carrier gas is applied coaxially to the vaporization plume providing confined radial expansion dynamics of the particles. Vaporized particles are then transported through a tube and enter the nebulizing gas sheath of an electrospray ionization (ESI) needle where capture and post-ionization of the analyte occurs. Analysis of four selected pharmaceutical compounds revealed enhanced sensitivity and improved reproducibility of remote LEMS when compared to conventional LEMS measurements. This dissertation also explores the possibility of using a nanosecond laser as a means to vaporize samples from stainless steel and glass slides for LEMS analysis. Wet samples of myoglobin on stainless steel were successfully vaporized by ns laser pulses while irradiation of myoglobin on glass did not result in vaporization. In a comparison study, fs laser pulses were able to vaporize wet myoglobin from both substrates. To achieve vaporization from glass, surfactant-free gold nanostars (GNS) were successfully used as a matrix for desorption and detection of myoglobin using ns-LEMS. This dissertation also reports the first synthesis of gold nanostars (GNS) exploiting the conversion of dual microplasma generated Au clusters to GNS in aqueous solutions of KAuCl4 containing small amounts of AgNO3, without addition of a surfactant or a stabilizing agent. The single-cell dual microplasma source is also a novel apparatus. Primary experiments using dual microplasma processing yielded various sized spherical gold nanoparticles (AuNPs) with polydispersity index (PDI) of 0.29. By kinetic control of post microplasma reduction, monodispersed nanospheres were produced with PDI of 0.06. An important discovery was the excess amount of hydrogen peroxide produced during microplasma process, making the production of GNS possible.

Book Miniaturization and Mass Spectrometry

Download or read book Miniaturization and Mass Spectrometry written by Severine le Gac and published by Royal Society of Chemistry. This book was released on 2008-12-03 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent explosion in the use of analytical chemistry, particularly in the biological sciences, has led to a need for fast, reliable and highly sensitive tools able to handle small sample sizes. This book illustrates how microfluidics and lab-on-a-chip devices can satisfy the growing need for miniaturized and enhanced analysis. They lend themselves well to mass spectrometric detection as they use samples in the low microlitre range and are handled on a chip. Miniaturization and Mass Spectrometry focuses on one particular technique, mass spectrometry, whose popularity has increased dramatically in the last two decades with the increase in use of biological analysis and the development of two "soft" ionization techniques, ESI and MALDI. These enable the analysis of large but fragile biological molecules such as DNA, proteins and oligosaccharides. The book starts with an introduction to the coupling of microfluidics to mass spectrometry techniques. It then goes on demonstrate the advantages of such a coupling: the MS analysis benefits from improved sample preparation when performed on a chip while MS yields more information on the sample handled on the chip compared to conventional optical detection. A history on the developments in this field, starting from the off-chip coupling to the on-chip ionization, is also provided. Daniel Figeys, a pioneer in the development of microfluidic systems for MS analysis, describes the early beginnings of this hyphenated analysis technique. Solutions to couple microfluidic systems to the two most popular ionization methods, ESI and MALDI, are presented throughout the chapters. Various examples are given of the application of this microfluidics-MS hyphenated analysis technique to proteomics, metabolomics, organic chemistry and forensics. Coverage is not limited to academic research. The development of commercialized systems and their current use for routine biological analysis are also presented. Lastly, a future vision of the integration of the mass spectrometer on the chip is raised, as a last step to yield fully portable systems for on-site analysis.

Book Current Developments in Laser Ablation inductively Coupled Plasma mass Spectrometry for Use in Geology  Forensics  and Nuclear Nonproliferation Research

Download or read book Current Developments in Laser Ablation inductively Coupled Plasma mass Spectrometry for Use in Geology Forensics and Nuclear Nonproliferation Research written by and published by . This book was released on 2008 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focused on new applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The diverse fields that were investigated show the versatility of the technique. In Chapter 2, LA-ICP-MS was used to investigate the rare earth element (REE) profiles of garnets from the Broken Hill Deposit in New South Wales, Australia. The normalized REE profiles helped to shed new light on the formation of deposits of sulfide ores. This information may be helpful in identifying the location of sulfide ore deposits in other locations. New sources of metals such as Pg, Zn, and Ag, produced from these ores, are needed to sustain our current technological society. The application of LA-ICP-MS presented in Chapter 3 is the forensics analysis of automotive putty and caulking. The elemental analysis of these materials was combined with the use of Principal Components Analysis (PCA). The PCA comparison was able to differentiate the automotive putty samples by manufacturer and lot number. The analysis of caulk was able to show a differentiation based on manufacturer, but no clear differentiation was shown by lot number. This differentiation may allow matching of evidence in the future. This will require many more analyses and the construction of a database made up of many different samples. The 4th chapter was a study of the capabilities of LA-ICP-MS for fast and precise analysis of particle ensembles for nuclear nonproliferation applications. Laser ablation has the ability to spatially resolve particle ensembles which may contain uranium or other actinides from other particles present in a sample. This is of importance in samples obtained from air on filter media. The particle ensembles of interest may be mixed in amongst dust and other particulates. A problem arises when ablating these particle ensembles directly from the filter media. Dust particles other than ones of interest may be accidentally entrained in the aerosol of the ablated particle ensemble. This would cause the analysis to be skewed. The use of a gelatin substrate allows the ablation a particle ensemble without disturbing other particles or the gelatin surface. A method to trap and ablate particles on filter paper using collodion was also investigated. The laser was used to dig through the collodion layer and into the particle ensemble. Both of these methods fix particles to allow spatial resolution of the particle ensembles. The use of vanillic acid as a possible enhancement to ablation was also studied. A vanillic acid coating of the particles fixed on top of the gelatin substrate was not found to have any positive effect on either signal intensity or precision. The mixing of vanillic acid in the collodion solution used to coat the filter paper increased ablation signal intensity by a factor of 4 to 5. There was little effect on precision, though. The collodion on filter paper method and the gelatin method of resolving particles have shown themselves to be possible tools in fighting proliferation of nuclear weapons and material. Future applications of LA-ICP-MS are only limited by the imagination of the investigator. Any material that can be ablated and aerosolized is a potential material for analysis by LA-ICP-MS. Improvements in aerosol transport, ablation chamber design, and laser focusing can make possible the ablation and analysis of very small amounts of material. This may perhaps lead to more possible uses in forensics. A similar method to the one used in Chapter 3 could perhaps be used to match drug residue to the place of origin. Perhaps a link could be made based on the elements leached from the soil by plants used to make drugs. This may have a specific pattern based on where the plant was grown. Synthetic drugs are produced in clandestine laboratories that are often times very dirty. The dust, debris, and unique materials in the lab environment could create enough variance to perhaps match drugs produced there to samples obtained...

Book Investigating the Instrumentational Components of Laser Electrospray Mass Spectrometry

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.

Book Photoionization and Photo Induced Processes in Mass Spectrometry

Download or read book Photoionization and Photo Induced Processes in Mass Spectrometry written by Ralf Zimmermann and published by John Wiley & Sons. This book was released on 2021-07-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive coverage of laser-induced ionization processes for mass spectrometry analysis Drawing on the expertise of the leading academic and industrial research groups involved in the development of photoionization methods for mass spectrometry, this reference for analytical scientists covers both the theory and current applications of photo-induced ionization processes. It places widely used techniques such as MALDI side by side with more specialist approaches such as REMPI and RIMS, and discusses leading edge developments in ultrashort laser pulse desorption, to give readers a complete picture of the state of the technology. Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications starts with a complete overview of the fundamentals of the technique, covering the basics of the gas phase ionization as well as those of laser desorption and ablation, pulse photoionization, and single particle ionization. Numerous application examples from different analytical fields are described that showcase the power and the wide scope of photo ionization in mass spectrometry. -The first general reference book on photoionization techniques for mass spectrometry -Examines technologies and applications of gas phase resonance-enhanced multiphoton ionization mass spectrometry (REMPI-MS) and gas phase resonance ionization mass spectrometry (RIMS) -Provides complete coverage of popular techniques like MALDI -Discusses the current and potential applications of each technology, focusing on process and environmental analysis Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications is an excellent book for spectroscopists, analytical chemists, photochemists, physical chemists, and laser specialists.

Book Development of Laser Ablation Direct Analysis in Real Time Imaging mass Spectrometry  LADI MS  applications to Questions of Relevance to Forensic Science and Plant Biochemistry

Download or read book Development of Laser Ablation Direct Analysis in Real Time Imaging mass Spectrometry LADI MS applications to Questions of Relevance to Forensic Science and Plant Biochemistry written by Kristen L. Fowble and published by . This book was released on 2019 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Advances in MALDI and Laser Induced Soft Ionization Mass Spectrometry

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

Book Nano Antimicrobials

Download or read book Nano Antimicrobials written by Nicola Cioffi and published by Springer Science & Business Media. This book was released on 2012-02-26 with total page 563 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a high demand for antimicrobials for the treatment of new and emerging microbial diseases. In particular, microbes developing multidrug resistance have created a pressing need to search for a new generation of antimicrobial agents, which are effective, safe and can be used for the cure of multidrug-resistant microbial infections. Nano-antimicrobials offer effective solutions for these challenges; the details of these new technologies are presented here. The book includes chapters by an international team of experts. Chemical, physical, electrochemical, photochemical and mechanical methods of synthesis are covered. Moreover, biological synthesis using microbes, an option that is both eco-friendly and economically viable, is presented. The antimicrobial potential of different nanoparticles is also covered, bioactivity mechanisms are elaborated on, and several applications are reviewed in separate sections. Lastly, the toxicology of nano-antimicrobials is briefly assessed.

Book New Topics in Lasers and Electro optics

Download or read book New Topics in Lasers and Electro optics written by William T. Arkin and published by Nova Publishers. This book was released on 2006 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is expected that ongoing advances in optics will revolutionise the 21st century as they began doing in the last quarter of the 20th. Such fields as communications, materials science, computing and medicine are leaping forward based on developments in optics.

Book Development of Laser Ablation Single Particle Inductively Coupled Plasma Mass Spectrometry Methods for the Analysis of Multi elemental Nanoparticles In on Solid Supports

Download or read book Development of Laser Ablation Single Particle Inductively Coupled Plasma Mass Spectrometry Methods for the Analysis of Multi elemental Nanoparticles In on Solid Supports written by Timothy Ronald Holbrook and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Ablation

    Book Details:
  • Author : Tatiana Itina
  • Publisher : BoD – Books on Demand
  • Release : 2017-12-21
  • ISBN : 9535136992
  • Pages : 292 pages

Download or read book Laser Ablation written by Tatiana Itina and published by BoD – Books on Demand. This book was released on 2017-12-21 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shortly after the demonstration of the first laser, the most intensely studied theoretical topics dealt with laser-matter interactions. Many experiments were undertaken to clarify the major ablation mechanisms. At the same time, numerous theoretical studies, both analytical and numerical, were proposed to describe these interactions. These studies paved the ways toward the development of numerous laser applications, ranging from laser micro- and nanomachining to material analysis, nanoparticle and nanostructure formation, thin-film deposition, etc. Recently, more and more promising novel fields of laser applications have appeared, including biomedicine, catalysis, photovoltaic cells, etc. This book intends to provide the reader with a comprehensive overview of the current state of the art in laser ablation, from its fundamental mechanisms to novel applications.

Book Direct Chemical Analysis of Solids by Laser Ablation in an Ion Storage Time of Flight Mass Spectrometer

Download or read book Direct Chemical Analysis of Solids by Laser Ablation in an Ion Storage Time of Flight Mass Spectrometer written by and published by . This book was released on 2003 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows direct viewing and selected analysis of the sample. Measurements identified trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Resolution (m/[mu]m) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

Book Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry

Download or read book Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry written by J. K. Holt and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse experiments have demonstrated simultaneous detection of up to 14 elements present in glasses in the ppm range. However, detection of the components has produced non-stoichiometric results due to difference in ionization potentials and fractionation effects. Time-of-flight secondary ionization mass spectrometry (TOF-SIMS) was used to spatially map elemental species on the surface and provide further evidence of fractionation effects. Resolution (m/Dm) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Induced Breakdown Spectroscopy

Download or read book Laser Induced Breakdown Spectroscopy written by Jagdish P. Singh and published by Elsevier. This book was released on 2007-10-03 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser induced breakdown spectroscopy (LIBS) is basically an emission spectroscopy technique where atoms and ions are primarily formed in their excited states as a result of interaction between a tightly focused laser beam and the material sample. The interaction between matter and high-density photons generates a plasma plume, which evolves with time and may eventually acquire thermodynamic equilibrium. One of the important features of this technique is that it does not require any sample preparation, unlike conventional spectroscopic analytical techniques. Samples in the form of solids, liquids, gels, gases, plasmas and biological materials (like teeth, leaf or blood) can be studied with almost equal ease. LIBS has rapidly developed into a major analytical technology with the capability of detecting all chemical elements in a sample, of real- time response, and of close-contact or stand-off analysis of targets. The present book has been written by active specialists in this field, it includes the basic principles, the latest developments in instrumentation and the applications of LIBS . It will be useful to analytical chemists and spectroscopists as an important source of information and also to graduate students and researchers engaged in the fields of combustion, environmental science, and planetary and space exploration. * Recent research work* Possible future applications* LIBS Principles