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Providing ultra-sensitive solutions for real-time trace gas analysis since 1998

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PTR-MS

Proton Transfer Reaction - Mass Spectrometry

PTR-MS (Proton Transfer Reaction – Mass Spectrometry) is the benchmark method for simultaneous real-time monitoring of volatile (organic) compounds (VOCs) without sample preparation in very low concentrations.

We're the market-leading PTR-MS company.

PTR-MS - trace gas analysis in real-time

IONICON PTR-MS systems are the most sensitive instruments for real-time monitoring of hundreds of Volatile Organic Compounds (VOCs), such as acetone, acetaldehyde, methanol, ethanol, benzene, xylene and many others, including some inorganic compounds, present in air.

The ionization by Proton Transfer Reaction (PTR) has several advantages: 

  1. very efficient - high sensitivity with LODs < 1 pptv, 
  2. very soft - with little to no and adjustable fragmentation,
  3. does not require pre-separation, such as GC, 
  4. and no sample preparation is necessary. 

Together this allows for trace gas analysis in real-time.

IONICON combines the unique PTR ionization with state-of-the-art Mass Spectrometry (MS):

  1. high sensitivity quadrupole MS (QMS), or
  2. high sensitivity, high resolution Time-of-Flight (TOF) MS.

IONICON PTR-MS has become the benchmark method for simultaneous real-time monitoring of VOCs in ambient air with wide range of applications. Over 300 leading scientists, institutions and multinational corporations are among our customers. For more details, watch our webinar "A short introduction to PTR-MS":

Would you like to learn more? See the tab below or 

Download PTR-MS Flyer

Also have a look at our extended product range, including fastGC systems, additional ionization techniques (SRI), trace calibration devices, and customized and industrial process monitoring solutions based on PTR-MS.

Learn more about the benefits of PTR-MS

History

Originally developed by scientists at the Institut für Ionenphysik at the University of Innsbruck, Austria, PTR-MS has been commercialized by IONICON Analytik since 1998. We develop and manufacture ultra-sensitive real-time trace gas analyzers based on PTR-MS and other ionization technologies. Until 2016, more than 300 PTR-MS instruments were sold to our customers.

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 for both, quadrupole and time of flight based instruments, are the resulting benefits of our PTR-MS technology.

Soft and efficient chemical ionization

Proton transfer from H3O+ is a soft, low energetic ionization method, suppressing fragmentation of substances as compared to e.g. electron impact ionization often used in GC-MS instruments, thus minimizing complex mass spectra and improving the identification capability. However, another benefit of PTR-MS is that the energy level (E/N) in the PTR drift tube where the actual ionization takes place, can even be adjusted by the user. This flexibility is very important since it allows to precisely control and adapt the ion chemistry to the application.

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.
Note: Because of a highly sophisticated ion source design (hollow cathode discharge) we do not need a signal-diminishing mass filter to select these precursor ions, thus we can achieve outstanding sensitivity also for SRI-MS.

No sample preparation

A major advantage of PTR-MS is that the samples do not need to be prepared before the measurement (e.g. pre-concentration or chemical separation procedures), thus whole-air samples can be introduced directly into the drift tube allowing for dynamic headspace sampling or VOC flux measurements. We also offer multiplexing and autosampling solutions.

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, allowing e.g. for BVOC flux measurements. Averaging over minutes and long sampling intervals as in the case of less sensitive or "offline" technologies are not necessary with an IONICON PTR-MS.

Advanced time-of-flight MS technology

Time-of-flight based trace gas analyzers as compared to mass filter (quadrupole) based technologies (e.g. SIFT-MS or IMR-MS) have many advantages, such as:
- better separation and identification capabilities due to higher mass resolution and
- the acquisition of the entire mass range in a fraction of a second (quadrupoles require the same time for only one single mass to be analyzed) which increases speed and sensitivity dramatically, especially for complex mixtures.

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 (e.g. the portable PTR-QMS 300 weights only 70 kg) and space-saving which clearly puts PTR-MS 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. Remote connection, operation and support capabilities are fully implemented e.g. via the free "Teamviewer" application. Only 15 minutes after pressing the power-button, the PTR-QMS 300 is ready to measure. Little maintenance and small operating costs complete the whole package.

You're not yet convinced? Click here for some testimonials and references of our customers or let us do a free showcase for you!

Are you looking for scientific background information? Click here or download the IONICON technologies overview!

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