Pyrolysis mass spectrometry direct

Montaudo and co-workers have used direct pyrolysis mass spectrometry (DPMS) to analyse the high-temperature (>500°C) pyrolysis compounds evolved from several condensation polymers, including poly(bisphenol-A-carbonate) [69], poly(ether sulfone) (PES) and poly(phenylene oxide) (PPO) [72] and poly(phenylene sulfide) (PPS) [73]. Additionally, in order to obtain data on the involatile charred residue formed during the isothermal pyrolysis process, the pyrolysis residue was subjected to aminolysis, and then the aminolyzed residue analysed using fast atom bombardment (FAB) MS. During the DPMS measurements, EI-MS scans were made every 3 s continuously over the mass range 10-1,000 Da with an interscan time of 3 s. 

Qian, K. Killinger, W.E. Casey, M. Nicol, G.R. Rapid Polymer Identification by In-Source Direct Pyrolysis Mass Spectrometry and Library Searching Techniques. Anal. Chem. 1996, 68, 1019-1027. 

Schulten, H.-R. (1996). Direct pyrolysis-mass spectrometry of soils A novel tool in agriculture, ecology, forestry, and soil science. In Mass Spectrometry of Soils, Boutton,T. W., and Yamasaki, S., eds., Marcel Dekker, New York, pp. 373-436. 

Nature of product Direct pyrolysis mass spectrometry... 

Nature of product Direct pyrolysis mass spectrometry Cyclic trimer of n-hexyl isocyanate as the principle decomposition product, and small amounts of hexyl isocyanate (3)... 

The low volatility of macromolecules initially precluded the widespread application of MS analysis to polymer systems. Nevertheless, meaningful structural information can be extracted from the mass spectra of unvolatile macromolecules by El, Cl, and FI techniques, and this is due to the considerable attention that has been focused on the methods of characterization of polymers by Direct Pyrolysis Mass Spectrometry (UPMS). " ... 

Carroccio, S., Puglisi, C., Samperi, R, and Montaudo, G., Thermal Decomposition Mechanisms of Polyetherimide Investigated by Direct Pyrolysis Mass-Spectrometry, Macromol Chem., Phys, 200, 2345, 1999. 

K. Qian, W. Killinger, and M. Casey, Rapid polymer identification by in-source direct pyrolysis mass spectrometry and library searching techniques. Anal. Chem., 68 1019-1027 (1996). 

Thermal analysis of PS, poly-p-methylstyrene and polyalpha-methylstyrene was carried out using evolved-gas analysis by IR and mass spectrometry and direct-pyrolysis analysis by mass spectrometric techniques. Evolved-gas analysis, both by IR and mass spectrometry, revealed features due mainly to the corresponding monomers or stable, volatile and low relative molec.wt. degradation products. In direct-pyrolysis mass spectrometry, however, primary decomposition products and heavier fragments such as dimers and trimers could also be detected. The ion-temp, profiles of the corresponding monomer ions revealed information about the thermal stability of the polymers. 25 refs. (XXVIII Colloquium Spectroscopicum Internationale, York, UK, June/July 1993)... 

Liang and Shi [1] used Fourier-transform infrared spectroscopy and direct pyrolysis -mass spectrometry to elucidate the thermal degradation mechanism of these polymers. 

Qian and co-workers [129] used in-source direct pyrolysis mass spectrometry to identify 150 different polymers and copolymers. Library searching facilities were included to enable positive polymer identifications to be carried out. 

Qian et al carried out a rapid identification of polymers using a technique based on ion source direct pyrolysis mass spectrometry and library searching. Polymers were pyrolysed using a coiled filament designed for desorption chemical ionization/desorption electron ionization applications. Pyrolysis products were ionized at 70 ev electron impact. This yielded highly reproducible spectra characteristic of the polymer. Using these techniques and library searching a comprehensive library of 150 polymers was developed. 

Direct pyrolysis-mass spectrometry (Py-MS) is applied to determine the primary structure of macromolecules and to investigate selective thermal degradation mechanisms. This technique allows the thermal decomposition products of the polymer sample to be observed directly in the ion source of the mass spectrometer, so that the evolving products are ionised and continuously detected by repetitive mass scans almost simultaneously with their formation 805917 757742. Since pyrolysis is accomplished under high vacuum, the thermal fragments are readily removed from the hot zone, and because of the low probability of molecular collisions and fast detection the occurrence of secondary reactions... 

---