Technical Note: Performance of Chemical Ionization Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS) for the measurement of atmospherically significant oxygenated volatile organic compounds

Abstract

Abstract. The performance of a new chemical ionization reaction time-of-flight mass spectrometer (CIR-TOF-MS) utilising the environment chamber SAPHIR (Simulation of Atmospheric Photochemistry In a large Reaction ChamberForschungzentrum Jülich, Germany) is described. The work took place as part of the ACCENT (Atmospheric Composition and Change the European NeTwork for excellence) supported oxygenated volatile organic compound (OVOC) measurement intercomparison during January 2005. The experiment entailed the measurement of 14 different atmospherically significant OVOCs at various mixing ratios in the approximate range 10.0-0.6 ppbV. The CIR-TOF-MS operated throughout the exercise with the hydronium ion (H 3 O + ) as the primary chemical ionization (CI) reagent in order to facilitate proton transfer to the analyte OVOCs. The results presented show that the CIR time-of-flight mass spectrometer is capable of detecting a wide range of atmospheric OVOCs at mixing ratios of around 10 ppbV in "real-time" (i.e. detection on the one-minute time scale), with sub-ppbV measurement also achieved following an increase in averaging time to tens of minutes. It is shown that in general OVOC measurement is made with high accuracy and precision, with integration time, mixing ratio and compound dependent values as good as 4-13% and 3-15% respectively. It is demonstrated that CIR-TOF-MS has rapid multi-channel response at the required sensitivity, accuracy and precision for atmospheric OVOC measurement.

Gas-phase pesticide measurement using iodide ionization time-of-flight mass spectrometry

“…CIMS has been used in atmospheric chamber experiments to explore oxidation reactions and mechanisms with starting precursor concentrations between 1 and 100 ppb v (Paulot et al, 2009;Ehn et al, 2014;Wyche et al, 2007). The iodide ToF-CIMS is thus more than suitable for chamber and laboratory experiments of pesticide oxidation chemistry and kinetics.…”

Development and chamber evaluation of the MCM v3.2 degradation scheme for β-caryophyllene

“…The gas phase organic compounds within the chamber (including the precursor β-caryophyllene) were measured using Chemical Ionisation Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS), as described in detail by Wyche et al (2007). The CIR-TOF-MS instrument comprises a bespoke, temperature controlled ((40±1) • C) radioactive ( 241 Am) ion source/drift tube assembly, coupled via a system of ion transfer optics to an orthogonal time-of-flight mass spectrometer (Kore Technology, UK).…”

High resolution PTR-TOF: Quantification and formula confirmation of VOC in real time

“…In collaboration with Ionicon Analytik, we recently developed a PTR-TOF instrument with a mass resolu-tion that is better than those previously reported [12][13][14][15][16], and a detection limit that is at least one order of magnitude lower than of those demonstrated in the literature [14,16]. Application examples of the commercially available PTR-TOF system were shown by Jordan and coworkers [17].…”

“…Recently, several groups reported the coupling of a chemical ionization unit to a time of flight mass spectrometer [12][13][14][15]. Mass resolving power, m/⌬m, well in excess of 1000 (CIR-TOF-MS) [12] and detection limits in the 100 pptv range for 1 min integration time [14] were achieved.…”