CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS

IONICON’s new CHemical Analysis of aeRosol ON-line (CHARON) particle inlet coupled to IONICON PTR-TOFMS instruments quantitatively detects not only organic sub-µm particulate matter but also particulate ammonium and nitrate at single digit ng/m³ mass concentration levels in real-time.


The innovative new inlet enables IONICON PTR-TOFMS series instruments to measure aerosols straightaway with the most versatile, reliable and well-established technology for VOC analysis in the market: PTR-MS. A single instrument covers VOCs and allows, in addition, the molecular-level characterization of sub-µm particulate organic matter in real-time:

  • On-line and real-time characterization of non-refractory organic sub-µm particulate matter
  • Detects most of the atmospheric organic carbon with a single instrument
  • Low limits of detection enables laboratory-based and ambient measurements
  • A dedicated add-on to selected IONICON PTR-TOFMS series instruments

The Method

The CHARON PTR-TOFMS is an on-line analytical method capable of characterizing the molecular composition of sub-µm organic particles on a chemical composition level at a one-minute time-resolution. The CHARON particle inlet has a honeycomb-activated charcoal denuder that efficiently adsorbs organic gases and conveys particles, a thermo-desorber that evaporates non-refractory organic particulate matter at moderate temperatures of 100-160 °C and minimizes pressures of a few mbar, and a high-pressure aerodynamic lens system that collimates and extracts sub-µm particles.

These organics are later examined as gas-phase analytes using one of IONICON’s high-resolution PTR-TOFMS instruments. By coupling the CHARON inlet to a PTR-TOFMS, the VOC inlet stays totally operational. An automated valve system allows for programed switching between gas- and particle-phase measurements in addition to zeroing of the particle inlet.

CHARON has been created for commercial release in close partnership between the University of Innsbruck and IONICON. Just a few weeks after its introduction, the CHARON PTR-TOFMS won the 2017 innovation award by "The Analytical Scientist". In early 2018, CHARON for PTR-TOFMS won another trophy: the LABORPRAXIS application award 2018.


The CHARON PTR-TOFMS is an exclusive on-line and real-time particle analyzer. Off-line particle pre-concentration, for example, by collection/desorption on surfaces is not required. Analytical artifacts, which may lead to reactions on such collection surfaces or thermal degradation at high desorption temperatures and residence times, are efficiently decreased.

Furthermore, the CHARON particle inlet considerably extends the range of PTR-MS measurable compounds from gas-phase volatile and intermediate volatile organics (VOC and IVOC) to particle-phase intermediate, semi and low volatile organic compounds (IVOC, SVOC, and LVOC, respectively). Thus, the PTR-MS technology, IONICON uses allows for the detection of nearly the whole range of atmospheric organic carbon with a single instrument. The regulated chemical ionization at minimized pressures and defined reaction energies of a PTR-MS drift tube hinder the formation of ionic artifacts (for example, clusters of organics) that might be incorrectly attributed. Ionization usually proceeds at collision rates that are properly predictable (+/- 30%). Fragmentation because of ionization is usually low; between 60% - 100% of the organic mass concentrations can be directly calculated without the need of any extra corrections.

With its high degree of conserved chemical composition information and high temporal resolution, the CHARON PTR-TOFMS is thus the ideal analytical method to identify and quantitatively follow atmospheric particulate tracer compounds like polycyclic aromatic hydrocarbons and levoglucosan. One-minute resolved data of numerous identified chemical compositions increase the quality of source apportionment (for example, by positive matrix factorization; PMF) to an unseen level.

Application Example

In April 2017, a morning hour urban air-pollution event was measured in Innsbruck, Austria, and serves as a superb example for the exceptional analytical performance of CHARON PTR-TOFMS. Cold temperatures and a robust inversion resulted in a rapid accumulation of key particulate matter released from traffic and domestic heating. Good temporal agreements within parallel Scanning Mobility Particle Sizer (SMPS) measurements are attained. The chemical fingerprint includes the main biomass burning tracer levoglucosan, traffic markers including condensed polycyclic aromatic hydrocarbons (PAHs) and series of potential aliphatic hydrocarbons, the key constituents of lubricant oils.


The CHARON particle inlet is available as a special add-on for certain IONICON PTR-TOFMS series instruments and ideally integrated with the new PTR-TOF 6000 X2, for an ultimate performance experience, high mass resolving power and maximum detection sensitivity. Sensitivities and limits of detection are based on the performance of the applied instrument. The following specifications are typical for CHARON PTR-TOF 8000 series instruments.

. .
CHARON inlet air flow: ~ 500 ml/min
Gas phase denuder
    VOC adsorption:
    Particle transmission:

> 99.999% (at ambient concentrations)
> 90% for 80 nm < DP < 1000 nm
Particle enrichment factor: > 40 for DP = 150 – 1000 nm
reduced for 60 nm < DP < 150 nm
Temperature range: 100 – 160 °C
Volatility range: complete evaporation of IVOCs, SVOCs, LVOCs
reduced response for ELVOCs
Response time: single seconds (IVOCs, ammonium)
single minutes (LVOCs)
Limit of detection: 1 - 5 ng/m³ (1 min integration, m/z ~ 200)
Accuracy: < -10%/+40% (typical ambient mixture)
Power consumption: < 300 W

Specifications are subject to change without prior notice.

CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS

CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS - Picture 1
CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS - Picture 2
CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS - Picture 3
CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS - Picture 4
CHARON Real-Time Aerosol Inlet for IONICON PTR-TOFMS - Picture 5

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