The Vocus CI-TOF directly measures trace compounds in air in real time

Chemical ionization mass spectrometers with sub-ppt limits of detection for volatile organic and inorganic compounds (VOCs and VICs). Optimized for use in laboratory, industrial, and mobile applications.

Vocus CI-TOF Reactors

Flexible Ionization to Target Your Compounds of Interest​

Vocus ionizes molecules by controlled reactions with reagent ions in a reactor. Reagent ions are selective for specific classes of compounds. Vocus CI-TOFs are tailored to meet users' needs:

  • One reactor with a single reagent ion
  • One reactor that can switch between multiple reagent ions in a single experiment
  • Two reactors that can be interchanged between experiments, each with different reagent ions

Reagent IonAnalyte Compound ClassesExample ApplicationsReactor
H3O+ (PTR)Small oxygenated compounds, polar molecules, BTEX, PAHs, other aromaticsAir quality analysis, food and flavor, environmental contaminationPTR
NH4+ Highly functionalized VOCs, oxygenated compounds, peroxidesExplosives and narcotics detection, photochemical oxidation productsPTR
NO+Alcohols, substituted aromatics, cyclic and branched alkanes, long-chain semi-volatile alkanesVehicle exhaust, wine contaminantsPTR
O2+Alkanes, carbon disulfide, ammonia, halogenated compoundsAmbient air monitoring, vehicle exhaustPTR
IOxygenated organics, acids, peroxides, inorganic acids, inorganic compoundsAmbient air monitoring, biomass burning, SOA formation, semiconductorAim
BrIodine containing compounds, HO2 radicals, mono carboxylic acidsAmbient air monitoring, sea emissionsAim

Real-time Reagent Ion Switching.  Ions using the same reactor can be alternated during a single experiment in milliseconds to seconds.
Reactor Interchange. Reactors can be easily interchanged between experiments in less than 30 minutes.

Vocus CI-TOF PTR Reactor

PTR Reactor​

Proton transfer reaction mass spectrometry (PTR-MS) is a powerful technique for the analysis of a broad range of volatile organic compounds  (VOCs).   The proprietary Vocus PTR Reactor reduces wall losses and focuses ions with RF fields to give you up to 10x the sensitivity of other commercial PTR-MS. The Vocus PTR Reactor is further compatible with other reagent ions schemes , including ammonium adduct ionization - to target broader ranges of compounds.

Reagent Ions H3O+ (PTR), NH4+, NO+, O2+
Reagent Ion Switching Up to 3 ions during a single experiment Switching time: < 5 seconds
Reagent Ion Generation DC plasma
Operating Conditions Sampling flow: 100 sccm, Pressure: 2-4 mbar,  Axial gradient: 600 V

Aim Reactor

The Vocus Aim Reactor offers fast, sensitive detection of trace organic and inorganic compounds spanning the entire volatility range.   The flow tube reactor operates at an increased pressure to suppress fragmentation of analyte ions, and uses compact VUV sources to generate both positive and negative reagent ions.  

Reagent IonsI, Br
Reagent Ion SwitchingUp to 3 ions during a single experiment
Switching time: <5 seconds
Fast switching option: 0.25 seconds (2 reagent ions of single polarity)
Reagent Ion GenerationVUV Ion Source
Operating ConditionsSampling flow: 2000 sccm, Pressure: 50-100 mbar,    Axial gradient: Field Free
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