Desorption thermal analysis

Clausen, P. A and P. Wolkoff, Degradation Products of Tenax TA Formed during Sampling and Thermal Desorption Analysis Indicators of Reactive Species Indoors, Atmos. Environ., 31, 715-725 (1997). 

Figure 2.2 Filter/adsorbent sampler with backup adsorbent tube designed for thermal desorption analysis of SVOCs (Clausen and Wolkoff, 1997b).

Clausen, P.A. and Wolkoff, P. (1997a) Degradation produds of Tenax TA formed during sampling and thermal desorption analysis indicators of reactive spedes... 

Standard practice for selection of sorbents, sampling and thermal desorption analysis procedures for VOCs in air (and material emissions chambers)... 

VDA-Verband der Automobileindustrie Method 278 Thermal desorption analysis of organic emissions from car trim components German car industry method... 

Good agreement between the results of an online instrument and a pumped-thermal desorption analysis are demonstrated." " ... 

A.M. de Jong and J.W. Niemantverdriet. Thermal Desorption Analysis Comparative Test of Ten Commonly Applied Procedures. Surf. Sci. 233 355 (1990). 

In summary, the major problem with the techniques based on calorimetry is that it is not possible to infer any information about the type of functionality by using this approach alone. It is only possible to estimate hydrophobic/hydrophilic character of the carbon. Nevertheless, it provides usefiil information that could be complemented by other techniques such as infrared spectroscopy, or thermal desorption analysis. 

A. De Jong and J. Niemantsverdriet, Thermal desorption analysis comparative test of ten commonly applied procedures. Surface Science, vol. 233, pp. 355-365, 1990. 

VDA 278 (2011) Thermal Desorption Analysis of Organic Emissions for the Characterization of Non-Metallic Materials for Automobiles, October 2011, VDA Verband der Automobilindustrie, Germany, www.vda.de (accessed 2 November 2014). 

U.S. EPA, Eco Eogic International Gas-Phase Chemical Reduction Process, The Thermal Desorption Enit Applications Analysis Report, EPA/540/AR-94/504, Washington, D.C., 1994. 

E. S. Erancis, M. Wu, R B. Eamswoith and M. L. Lee, Supercritical fluid extraaion/gas cliromatography with thermal desorption modulator interface and niti O-specific detection for the analysis of explosives , 7. Microcolumn Sep. 7 23-28 (1995). 

A. J. H. Eouter, J. van Door-nmalen, J. J. Vreuls and U. A. Th Brinkman, On-line solid-phase extr-action-thermal desorption-gas chr-omatography with ion trap detection tandem mass spectr-ometr-y for the analysis of microcontaminants in water , 7. High Resolut. Chromatogr. 19 679-685(1996). 

Analysis of Thermal Desorption Data for Adsorption Studies... 

MDHS 1 Acrylonitrile in air Laboratory method using charcoal adsorption tubes and gas chromatography MDHS 2 Acrylonitrile in air Laboratory method using porous polymer adsorption tubes, and thermal desorption with gas chromatographic analysis... 

Purge-and-trap methods have also been used to analyze biological fluids for the presence of trichloroethylene. Breast milk and blood were analyzed for trichloroethylene by purging onto a Tenax gas chromatograph to concentrate the volatiles, followed by thermal desorption and analysis by GC/MS (Antoine et al. 1986 Pellizzari et al. 1982). However, the breast milk analysis was only qualitative, and recoveries appeared to be low for those chemicals analyzed (Pellizzari et al. 1982). Precision (Antoine et al. 1986) and sensitivity (Pellizzari et al. 1982) were comparable to headspace analysis. 

The apparatuses used for the studies of both ammonia synthesis emd hydrodesulfurization were almost identical, consisting of a UHV chamber pumped by both ion and oil diffusion pumps to base pressures of 1 x10 " Torr. Each chamber was equipped with Low Energy Electron Diffraction optics used to determine the orientation of the surfaces and to ascertain that the surfaces were indeed well-ordered. The LEED optics doubled as retarding field analyzers used for Auger Electron Spectroscopy. In addition, each chamber was equipped with a UTI 100C quadrupole mass spectrometer used for analysis of background gases and for Thermal Desorption Spectroscopy studies. 

Alternative approaches consist in heat extraction by means of thermal analysis, thermal volatilisation and (laser) desorption techniques, or pyrolysis. In most cases mass spectrometric detection modes are used. Early MS work has focused on thermal desorption of the additives from the bulk polymer, followed by electron impact ionisation (El) [98,100], Cl [100,107] and field ionisation (FI) [100]. These methods are limited in that the polymer additives must be both stable and volatile at the higher temperatures, which is not always the case since many additives are thermally labile. More recently, soft ionisation methods have been applied to the analysis of additives from bulk polymeric material. These ionisation methods include FAB [100] and LD [97,108], which may provide qualitative information with minimal sample pretreatment. A comparison with FAB [97] has shown that LD Fourier transform ion cyclotron resonance (LD-FTTCR) is superior for polymer additive identification by giving less molecular ion fragmentation. While PyGC-MS is a much-used tool for the analysis of rubber compounds (both for the characterisation of the polymer and additives), as shown in Section 2.2, its usefulness for the in situ in-polymer additive analysis is equally acknowledged. 

Thermal desorption of solid traps by microwave energy is unsuitable for thermally labile compounds. In microwave thermal analysis [431] the (solid) sample is heated directly via interactions of the microwaves with the sample, providing more even heating and reduction of temperature gradients in comparison to heating with electrical furnaces. By passing air over a microwave-heated volatile sample evolved gases may be collected [432]. 

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