Thermal desorption mass spectrometry

H. D. Beckey. Field Desorption Mass Spectrometry A Technique for the Study of Thermally Unstable Substances of Low Volatility. Int. J. Mass Spectrom. Ion Phys., 2(1969) 500-503. 

Thermal desorption mass spectrometry is a rapid technique for the determination of oil in soils and sediments [9]. This method exhibited lower analytical variance compared to Soxhlet extraction, i.e. followed by conventional analysis. The analysis time for wet soil samples was about 20min. 

The presence of cyanamides of Cd and Pb in films of (Cd,Pb)S was confirmed by thermal desorption mass spectrometry [23]. Cyanamide (H2CN2) is a product of the decomposition of thiourea and forms sparingly soluble metal salts. The metal cyanamide content of the film varied from ca. 5% up to ca. 20% (by weight). The presence of the cyanamides decreased the intensity of the XRD reflections, presumably due to poorer crystallization of the sulphides. Interestingly, the photosensitivity of the films increased with higher metal cyanamide content, although whether this was due specifically to the presence of the cyanamide or to its effect on the crystal growth was not known. 

Field-desorption mass spectrometry (FDMS), where no evaporation prior to ionization is required, has been successfully used in the analysis of in volatile phosphonium salts113, although a direct thermal process gave similar spectra114. In the case where the FD spectra are complex, a chemical ionization technique may give wider applicability115. The cation is the base peak for monophosphonium salts when the [2M + anion]+ cationic species is the one for bisphosphonium compounds. 

Conventional electron impact or chemical ionization mass spectrometry requires that volatilization precede ionization and this is clearly a limiting factor in the analysis of many biochemically significant compounds. A newer ionization technique, field desorption (FD) (1, 2 ) removes this requirement and makes it possible to obtain mass spectrometric information on thermally unstable or non-volatile organic compounds such as glycoconjugates and salts. This development is particularly significant for those concerned with the analysis of glycolipids and we have therefore explored the suitability of field desorption mass spectrometry (FDMS) for this class of compounds. We have evaluated experimental procedures in order to enhance the efficiency of the ionization process and to maximize the information content of spectra obtained by this technique. 

Freon or dichloromethane extraction gives precise and accurate estimates of oil and grease contents of soil [104]. Thermal desorption mass spectrometry has been used as a rapid method for the determination of oil in soil. The analysis takes only 20 minutes [33]. 

Beckey, H. D. (1969). Field desorption mass spectrometry, a technique for the study of thermally unstable substances of low volatility. Ini. I. Mass Spectrom. Ion Phys. 2, 500-503. 

Abstract. Gas interstitial fullerenes was produced by precipitation of C6o from the solution in 1,2 dichlorobenzene saturated by O2, N2, or Ar. The structure and chemical composition of the fullerenes was characterized by X-ray powder diffraction analysis, FTIR spectroscopy, thermal desorption mass spectrometry, differential scanning calorimetric and chemical analysis. The images of fullerene microcrystals were analyzed by SEM equipped with energy dispersive X-ray spectroscopy (EDS) attachment. Thermal desorption mass spectroscopy and EDS analysis confirmed the presence of Ar, N and O in C60 specimens. From the diffraction data it has been shown that fullerite with face centered cubic lattice was formed as a result of precipitation. The lattice parameter a was found to enhance for precipitated fullerene microcrystals (a = 14.19 -14.25 A) in comparison with that for pure C60 (a = 14.15 A) due to the occupation of octahedral interstices by nitrogen, oxygen or argon molecules. The phase transition temperature and enthalpy of transition for the precipitated fullerene microcrystals decreased in comparison with pure Cgo- Low temperature wet procedure described in the paper opens a new possibility to incorporate chemically active molecules like oxygen to the fullerene microcrystals. 

To confirm the presence of gas molecules in the fullerene crystals we used thermal desorption mass spectrometry analysis. Before each measurement the sample was held for fixed periods of 3 h at temperatures 65, 150 and 270°C in enclosed quartz... 

Thermogravimetric analysis was performed on a Stanton Redcroft thermobalance in a flowing oxygen atmosphere at a heating rate of 10°C/minute. Thermal desorption/mass spectrometry (TD/MS) was carried out using am Extranuclear quadrupole mass spectrometer. 4 ... 

Land, D.P., Tai, T.-L., Lindquist, J.M., Hemminger, J.C. and Mclver, R.T. (1987). Characterization of multilayer thin films by laser-induced thermal desorption mass spectrometry. Anal. Chem. 59, 2924-2927. 

Thermogravimetric analysis (tga) and thermal desorption/mass spectrometry (td/ms) were used as described previously [5]. Sample sizes were typically 10 mg, with heating rates of 10°C/min. 

QUANTITATIVE THERMAL DESORPTION/MASS SPECTROMETRY OF AIPO4-II PRECURSORS N.J. TAPP and N.B. MILESTONE... 

Crystalline products with the structure of AIPO4-II have been produced using four different amines as structure-directing species. A method for quantifying the amount of amine in the precursors has been developed. This involves the use of thermal desorption/mass spectrometry in combination with thermo-gravimetry. This method also provides information as to the distribution of the water within the structure. 

L.H. Dubois, D.G. Castner, and G.A. Somoijai. A Low Energy Electron Diffraction (LEED), High Resolution Electron Energy Loss (ELS), and Thermal Desorption Mass Spectrometry (TDS) Study. J. Chem. Phys. 72 5234 (1980). 

It has been demonstrated experimentally by thermal desorption mass spectrometry that the adsorption mechanism of hydrogen on purified SWCNTs at low temperature is due to physical adsorption. 

Finally, as concerns Pt(lll), the reaction of co-adsorbed ethene-d4 and hydrogen has been studied using a combination of laser-induced thermal desorption, mass-spectrometry and RAIRS exchange occurred above 215 K with an activation energy of 46 kJ mol this being below the point at which conversion to... 

ECTDMS Electrochemical thermal desorption mass spectrometry... 

Saito, J., Teramae, N., Hara, J., Toda, S., and Tanaka, S., Anal5 is of thermal behavior of styrene oligomers by field desorption mass spectrometry, Kobunshi Ronbunshu, 40, 485, 1983. 

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