Author: R. N. Isaev Publisher: ISBN: Category : Languages : en Pages : 6
Book Description
Mass spectrometric analysis, performed in the course of thermolysis of solids (under isothermal or nonisothermal conditions), allows one to produce information on the specific features and mechanism of thermolysis. The system for introducing the specimen to be analyzed into the device is varied, depending on the specific tasks at hand.
Author: Publisher: ISBN: Category : Languages : en Pages : 31
Book Description
Thermal decomposition of poly dimethyl siloxane compounds, Sylgard{reg_sign} 184 and 186, were examined using thermal desorption coupled gas chromatography-mass spectrometry (TD/GC-MS) and multivariate analysis. This work describes a method of producing multiway data using a stepped thermal desorption. The technique involves sequentially heating a sample of the material of interest with subsequent analysis in a commercial GC/MS system. The decomposition chromatograms were analyzed using multivariate analysis tools including principal component analysis (PCA), factor rotation employing the varimax criterion, and multivariate curve resolution. The results of the analysis show seven components related to offgassing of various fractions of siloxanes that vary as a function of temperature. Thermal desorption coupled with gas chromatography-mass spectrometry (TD/GC-MS) is a powerful analytical technique for analyzing chemical mixtures. It has great potential in numerous analytic areas including materials analysis, sports medicine, in the detection of designer drugs; and biological research for metabolomics. Data analysis is complicated, far from automated and can result in high false positive or false negative rates. We have demonstrated a step-wise TD/GC-MS technique that removes more volatile compounds from a sample before extracting the less volatile compounds. This creates an additional dimension of separation before the GC column, while simultaneously generating three-way data. Sandia's proven multivariate analysis methods, when applied to these data, have several advantages over current commercial options. It also has demonstrated potential for success in finding and enabling identification of trace compounds. Several challenges remain, however, including understanding the sources of noise in the data, outlier detection, improving the data pretreatment and analysis methods, developing a software tool for ease of use by the chemist, and demonstrating our belief that this multivariate analysis will enable superior differentiation capabilities. In addition, noise and system artifacts challenge the analysis of GC-MS data collected on lower cost equipment, ubiquitous in commercial laboratories. This research has the potential to affect many areas of analytical chemistry including materials analysis, medical testing, and environmental surveillance. It could also provide a method to measure adsorption parameters for chemical interactions on various surfaces by measuring desorption as a function of temperature for mixtures. We have presented results of a novel method for examining offgas products of a common PDMS material. Our method involves utilizing a stepped TD/GC-MS data acquisition scheme that may be almost totally automated, coupled with multivariate analysis schemes. This method of data generation and analysis can be applied to a number of materials aging and thermal degradation studies.
Author: Peter Kusch Publisher: BoD – Books on Demand ISBN: 1789849586 Category : Science Languages : en Pages : 104
Book Description
Analytical pyrolysis deals with the structural identification and quantitation of pyrolysis products with the ultimate aim of establishing the identity of the original material and the mechanisms of its thermal decomposition. The pyrolytic process is carried out in a pyrolyzer interfaced with analytical instrumentation such as gas chromatography (GC), mass spectrometry (MS), gas chromatography coupled with mass spectrometry (GC/MS), or with Fourier-transform infrared spectroscopy (GC/FTIR). By measurement and identification of pyrolysis products, the molecular composition of the original sample can often be reconstructed.This book is the outcome of contributions by experts in the field of pyrolysis and includes applications of the analytical pyrolysis-GC/MS to characterize the structure of synthetic organic polymers and lignocellulosic materials as well as cellulosic pulps and isolated lignins, solid wood, waste particle board, and bio-oil. The thermal degradation of cellulose and biomass is examined by scanning electron micrography, FTIR spectroscopy, thermogravimetry (TG), differential thermal analysis, and TG/MS. The calorimetric determination of high heating values of different raw biomass, plastic waste, and biomass/plastic waste mixtures and their by-products resulting from pyrolysis is described.
Author: Boris V. L'vov Publisher: Springer ISBN: 9781402056710 Category : Science Languages : en Pages : 247
Book Description
This book covers the results of investigations into the mechanisms and kinetics of thermal decompositions of solid and liquid substances on the basis of thermochemical analyses. The main features of these reactions are explained and many problems and unusual phenomena, which have accumulated in this field are interpreted. New methods of TA measurement and calculation have been developed, which permit the precision and accuracy of determination of kinetic parameters to be increased substantially.
Author: Yu M. Sotnikov-Yuzhnik Publisher: ISBN: Category : Languages : en Pages : 11
Book Description
The evolution kinetics of one of several gaseous reaction products of the thermal decomposition of solids can be studied by means of different methods suitable for determining the concentration of a given product in a flow of a foreign gas. In their discrimination capacity they are usually inferior to the radiometric method, but enable one to work with standard untagged substances. The report primarily describes the spectral methods used. Infrared spectroscopy was used to study the evolution of carbon dioxide in the case of thermal decomposition of manganese carbonate under nonisothermic conditions. Essentially the method consisted of sending the carrier gas, which carries the evolved gaseous reaction products, through the reaction vessel of the Chevenard balance to the gas cuvette of the spectrophotometer. As the temperature increases a change in intensity of one of the infrared carbon dioxide absorption bands is observed. (Author).
Author: Oliver Terzic Publisher: ISBN: 9789491407451 Category : Languages : en Pages : 221
Book Description
"The Organisation for the Prohibition of Chemical Weapons (OPCW) is the international organisation set to oversee the implementation of the Chemical Weapons Convention treaty that prohibits the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons by States Parties. To this end, the OPCW has established the strict verification procedures relying essentially upon the on-site sampling and analysis. A transportable analytical laboratory was carefully assembled and versed to fit the task. Following more frequent deployment, a major deficiency of the on-site laboratory capacity and the number of weaknesses of the on-site sample preparation approach were revealed. The aim of this PhD thesis was to enhance the capability and efficiency of the OPCW on-site laboratory. The work resulted in a set of novel analytical methods and strategies for the gas chromatography-mass spectrometry instrumental technique that are not restricted to the chemical warfare agent related field, but also convenient for any forensic or environmental field laboratory use."--Samenvatting auteur.
Author: Oliver Terzic Publisher: ISBN: 9789491407451 Category : Languages : en Pages : 0
Book Description
"The Organisation for the Prohibition of Chemical Weapons (OPCW) is the international organisation set to oversee the implementation of the Chemical Weapons Convention treaty that prohibits the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons by States Parties. To this end, the OPCW has established the strict verification procedures relying essentially upon the on-site sampling and analysis. A transportable analytical laboratory was carefully assembled and versed to fit the task. Following more frequent deployment, a major deficiency of the on-site laboratory capacity and the number of weaknesses of the on-site sample preparation approach were revealed. The aim of this PhD thesis was to enhance the capability and efficiency of the OPCW on-site laboratory. The work resulted in a set of novel analytical methods and strategies for the gas chromatography-mass spectrometry instrumental technique that are not restricted to the chemical warfare agent related field, but also convenient for any forensic or environmental field laboratory use."--Samenvatting auteur.
Author: Publisher: ISBN: Category : Languages : en Pages : 8
Book Description
Simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) and time-of-flight velocity (TOF) spectra have been developed to study reactions that occur during the thermal decomposition of liquids and solids. The data obtained with these techniques are the identity of the reaction products and their rates of gas formation as a function of time. Over the past several years, these techniques have been applied to the study of energetic materials that are used in propellants and explosives. In this presentation, the details of the STMBMS and TOF velocity spectra techniques will be reviewed, the advantages of the techniques over more conventional thermal analysis and mass spectrometry measurements will be discussed, and the use of the techniques will be illustrated with results on the thermal decomposition of hexahydro-1,3,5-trinitro-s-triazine (RDX).
Author: R. N. Isaev
Author: 
Author: Peter Kusch
Author: Boris V. L'vov
Author: Daniel Bombick
Author: Yu M. Sotnikov-Yuzhnik
Author: Oliver Terzic
Author: Sebastian Wohlfahrt
Author: Oliver Terzic
Author: