Online quantification without calibration

PTR-MS provides absolute quantitative analysis in real-time. The generation of the precursor reagent ions and the chemical ionization of the VOCs are individually controlled and spatially separated processes. This leads to constant and well defined conditions in the drift tube (unlike IMS, APCI-MS and similar technologies) making the determination of absolute concentrations possible without the use of gas standards.

Market-leading low online detection limit

H3O+ ions do not react with any of the major components present in clean air due to their low proton affinity. Unlike other technologies (e.g. SIFT-MS or IMR-MS) PTR-MS does not dilute low concentrated samples by a carrier gas and does not lose precursor ions on their way through a mass filter between the ion source and the drift tube. This makes PTR-MS very sensitive to trace gases in the sample air. Very high intensities of precursor ions and thus real single-digit pptv-range detection limits.

Soft and efficient chemical ionization

Proton transfer from H3O+is a soft ionization method, keeping fragmentation rates rather low as compared to e.g. electron impact ionization often used in GC-MS instruments, thus minimizing coincidences in the mass spectra and improving the identification capability.

Optional: Selective Reagent Ionization - Mass Spectrometry (SRI-MS)

By using not only H3O+ but also NO+ and O2+ or Kr+ and Xe+, as reagent ions as an optional configuration of IONICON PTR-MS instruments, separation of isomeric compounds in real-time is now possible. Additionally, nearly all substances that could not be ionized with H3O+ due to their low proton affinity are now detectable.

No sample preparation

A major advantage of PTR-MS is that the samples do not need to be prepared before the measurement, thus whole-air samples can be introduced directly into the drift tube allowing for dynamic headspace sampling or VOC flux measurements.

The real-time advantage

PTR-MS is an "online" mass spectrometric technology providing real-time data due to its very fast response time of less than 100ms.

Robust and easy to use

No gas supply is necessary to operate an IONICON PTR-MS (i.e. for H3O+ and NO+ reagent ions). Our instruments are light-weight and space-saving which clearly puts us ahead of competing technologies. IONICON PTR-MS systems are often used for field campaigns or variable location measurements and can be operated in nearly every environment. Only 15 minutes after pressing the power-button, the PTR-QMS 300 is ready to measure.