mass range: 10-600 Th
mass resolving power: 900 Th/Th FWHM *
mass accuracy: 100 mTh
extraction rate: up to 80 kHz
spectra rate: 10 Hz
ionization: EI, SPI, EI/SPI
Quad Filter: low cut-off
dynamic range: 10^6
gas flow into ion source: 1 std ml/min = 1 sccm
matrix gas: He, N2, Ar also air or O2
ion rate: 1000 ions/extraction
different VUV sources: for different energies

DECOMPOSITION OF POLYMERES
Polystyrene (PS): The SPI mass spectrum shows that in addition to the dominating 

styrene monomer peak at 104 m/z, also the styrene dimer (208 m/z) and styrene trimer (312 m/z) are formed. Due to the resonance stabilization of the styrene monomer the alkane backbone of the PS polymer readily is breaking after every second chain carbon, forming predominately styrene (C2-phenyl unit). However, the occurrence of toluene (C1-phenyl unit), phenyl propene (C3-phenyl unit) and phenyl butadiene (C4-phenyl unit) shows that other chain braking positions are possible, although less probable.

Acronitrile-Butadiene-Styrene (ABS): The most dominant species in the evolved gas phase SPI mass spectrum is styrene (104 m/z) surrounded by the C1 and C3-benzene products from the polymer chain degradation (toluene and propenyl benzene). At 157 m/z the condensation product of acrylonitrile and styrene is visible and at 208 m/z the styrene dimer can be seen in the SPI mass spectrum.

CHARACTERIZATION OF CRUDE OIL

Crude oils are often characterized according to their physical properties such as density, viscosity, color, and odor. Furthermore, they may be distinguished by determining their chemical composition on a molecular level, which is challenging due to the enormous number of components present in the oils. In the displayed mass spectra alkanes (linear and branched), cycloalkanes and substituted benzenes occur in long homologous series and are assigned by the different colored dots red, green and blue, respectively. The SPI mass spectra from thermal analysis of different crude oils clearly show the advantage of soft photo ionization for the characterization of the evolving gases. Since fragmentation does not occur, each hydrocarbon may be identified according to its molecular peak. Different crude oils can be easily identified and characterized based on their distinct molecular patterns of the released compounds.

The thermogravimetry SPI-MS setup consists of a thermobalance which is coupled to an oaTOF mass spectrometer. The coupling is carried out via a heated capillary, which transfers the gas molecules evolving in the thermobalance into the ion source. There, the molecules are ionized either by VUV photons or by 70eV-electrons in case of conventional EI.