Photonion has developed a new on-line real-time measuring system for chemical gas analysis based on time-of-flight mass spectrometry (TOF-MS). This technology is now integrated in the VITROCELL® modules in order to analyse the sampling at the spot where the cells are exposed.
Three different ionization techniques are applicable:
- single photon ionization (SPI) with a special VUV
- excimer source or laser VUV source
- resonance enhanced multiphoton ionization (REMPI) with a laser beam
- electron impact ionization (EI).
SPI and REMPI are considered as soft ionization techniques allowing the acquisition of mass spectra with nearly no fragmentation. A heated transfer line allows direct gas analysis of e. g. engine exhaust, cigarette smoke or e-cigarette vapors.
Gaseous samples are addressed continuously by the Photo-TOF-MS mass spectrometry system at a flow rate of approx. 2mL/min. Depending on the ionization technique various relevant species can be ionized by SPI, REMPI or EI. After the ionization, the formed ions are accelerated into the reflectron time-of-flight mass analyzer where they are separated due to their different mass to charge ratios.
A typical TOF mass spectrum can be generated in some milliseconds.This fast on-line measurement system is a selective and sensitive analytical method to investigate complex gas mixtures such as from combustion processes.