scholarly journals A method for extracting calibrated volatility information from the FIGAERO-HR-ToF-CIMS and its experimental application

2019 ◽  
Vol 12 (3) ◽  
pp. 1429-1439 ◽  
Author(s):  
Thomas J. Bannan ◽  
Michael Le Breton ◽  
Michael Priestley ◽  
Stephen D. Worrall ◽  
Asan Bacak ◽  
...  
Keyword(s):  
Vapour Pressure ◽  
Homologous Series ◽  
Measurement Techniques ◽  
Ionization Mass ◽  
Particle Phase ◽  
Knudsen Effusion ◽  
Vapour Pressure Measurement ◽  
Knudsen Effusion Mass Spectrometry ◽  
Real Atmosphere

Abstract. The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet specifically designed to be coupled with the Aerodyne High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS). The FIGAERO-HR-ToF-CIMS provides simultaneous molecular information relating to both the gas- and particle-phase samples and has been used to extract vapour pressures (VPs) of the compounds desorbing from the filter whilst giving quantitative concentrations in the particle phase. However, such extraction of vapour pressures of the measured particle-phase components requires use of appropriate, well-defined, reference compounds. Vapour pressures for the homologous series of polyethylene glycols (PEG) ((H-(O-CH2-CH2)n-OH) for n=3 to n=8), covering a range of vapour pressures (VP) (10−1 to 10−7 Pa) that are atmospherically relevant, have been shown to be reproduced well by a range of different techniques, including Knudsen Effusion Mass Spectrometry (KEMS). This is the first homologous series of compounds for which a number of vapour pressure measurement techniques have been found to be in agreement, indicating the utility as a calibration standard, providing an ideal set of benchmark compounds for accurate characterization of the FIGAERO for extracting vapour pressure of measured compounds in chambers and the real atmosphere. To demonstrate this, single-component and mixture vapour pressure measurements are made using two FIGAERO-HR-ToF-CIMS instruments based on a new calibration determined from the PEG series. VP values extracted from both instruments agree well with those measured by KEMS and reported values from literature, validating this approach for extracting VP data from the FIGAERO. This method is then applied to chamber measurements, and the vapour pressures of known products are estimated.

scholarly journals A method for extracting calibrated volatility information from the FIGAERO-HR-ToF-CIMS and its application to chamber and field studies

2018 ◽  
Author(s):  
Thomas J. Bannan ◽  
Michael Le Breton ◽  
Michael Priestley ◽  
Stephen D. Worrall ◽  
Asan Bacak ◽  
...  
Keyword(s):  
Vapour Pressure ◽  
Homologous Series ◽  
Measurement Techniques ◽  
Field Studies ◽  
Particle Phase ◽  
Knudsen Effusion ◽  
Vapour Pressure Measurement ◽  
Knudsen Effusion Mass Spectrometry ◽  
Real Atmosphere ◽  
Chamber Measurements

Abstract. The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet specifically designed to be coupled with the Aerodyne High Resolution (HR)-Time of flight (ToF)-Chemical ionisation mass spectrometer (CIMS). The FIGAERO-HR-ToF-CIMS provides simultaneous molecular information relating to both the gas and particle phase samples and has been used to extract vapour pressures of the compounds desorbing from the filter, whilst giving quantitative concentrations in the particle phase. However, such extraction of vapour pressures of the measured particle phase components requires use of appropriate, well-defined, reference compounds. Vapour pressures for the homologous series of polyethylene glycols (PEG) ((H−(O−CH2−CH2)n−OH) for n = 3 to n = 8), covering a range of vapour pressures (VP) (10−1 to 10−7 Pa) that are atmospherically relevant have been shown to be reproduced well by a range of different techniques, including Knudsen Effusion Mass Spectrometry (KEMS). This is the first homologous series of compounds for which a number of vapour pressure measurement techniques have been found to be in agreement, indicating the utility as a calibration standard, providing an ideal set of benchmark compounds for accurate characterisation of the FIGAERO for extracting vapour pressure of measured compounds in chambers and the real atmosphere. To demonstrate this, single component and mixture vapour pressure measurements are made using two FIGAERO-HR-ToF-CIMS instruments based on a new calibration determined from the PEG series. VP values extracted from both instruments agree well with those measured by KEMS and reported values from literature, validating this approach for extracting VP data from the FIGAERO. This method is then applied to chamber measurements and the vapour pressures of known products are estimated.

scholarly journals Coupling a gas chromatograph simultaneously to a flame ionization detector and chemical ionization mass spectrometer for isomer-resolved measurements of particle-phase organic compounds

2020 ◽  
Author(s):  
Chenyang Bi ◽  
Jordan E. Krechmer ◽  
Graham O. Frazier ◽  
Wen Xu ◽  
Andrew T. Lambe ◽  
...  
Keyword(s):  
Functional Groups ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Measurement Techniques ◽  
Oxidation Products ◽  
Ionization Mass ◽  
Particle Phase ◽  
Gas Chromatograph ◽  
New Instrument

Abstract. Atmospheric oxidation products of volatile organic compounds consist of thousands of unique chemicals that have distinctly different physical and chemical properties depending on their detailed structures and functional groups. Measurement techniques that can achieve molecular characterizations with details down to functional groups (i.e., isomer-resolved resolution) are consequently necessary to provide understandings of differences of fate and transport within isomers produced in the oxidation process. We demonstrate a new instrument coupling the thermal desorption aerosol gas chromatograph (TAG), which enables the separation of isomers, with the high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS), which has the capability of classifying unknown compounds by their molecular formulas, and the flame ion detector (FID), which provide a near-universal response to organic compounds. The TAG-CIMS/FID is used to provide isomer-resolved measurements of samples from liquid standard injections and particle-phase organics generated in oxidation flow reactors. By coupling a TAG to a CIMS, the CIMS is enhanced with an additional dimension of information (resolution of individual molecules) at the cost of time resolution (i.e., one sample per hour instead of per minute). We found that isomers are prevalent in sample matrix with an average number of three to five isomers per formula depending on the precursors in the oxidation experiments. Additionally, a multi-reagent ionization mode is investigated in which both zero air and iodide are introduced as reagent ions, to examine the feasibility of extending the use of an individual CIMS to a broader range of analytes with still selective reagent ions. While this approach reduces iodide-adduct ions by a factor of two, [M−H]− and [M+O2]− ions produced from lower-polarity compounds increase by a factor of five to ten, improving their detection by CIMS. The method expands the range of detected chemical species by using two chemical ionization reagents simultaneously, enabled by the pre-separation of analyte molecules before ionization.

scholarly journals Study of thermal stability of p-type skutterudites DD0.7Fe3CoSb12 by Knudsen effusion mass spectrometry

RSC Advances ◽  
2019 ◽  
Vol 9 (37) ◽  
pp. 21451-21459
Author(s):  
František Zelenka ◽  
Pavel Brož ◽  
Jan Vřešťál ◽  
Jiří Buršík ◽  
Gerda Rogl ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Stability ◽  
Vapour Pressure ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry ◽  
P Type ◽  
Thermal Stability Of

Antimony vapour pressure is measured by Knudsen effusion mass spectrometry in order to assess the thermal stability of p-type DD0.7Fe3CoSb12 thermoelectrics.

scholarly journals Determination of the thermodynamic activities of LiF and ThF4in the LixTh1−xF4−3xliquid solution by Knudsen effusion mass spectrometry

2015 ◽  
Vol 17 (44) ◽  
pp. 30110-30118 ◽  
Author(s):  
Elisa Capelli ◽  
Ondřej Beneš ◽  
Jean-Yves Colle ◽  
Rudy J. M. Konings
Keyword(s):  
Mass Spectrometry ◽  
Vapour Pressure ◽  
Liquid Solution ◽  
Knudsen Effusion ◽  
Thermodynamic Activities ◽  
Knudsen Effusion Mass Spectrometry

Vapour pressure and thermodynamic activities of LiF and ThF4in the liquid solution are studied by Knudsen effusion mass spectrometry.

scholarly journals Measured Solid State and Sub-Cooled Liquid Vapour Pressures of Benzaldehydes Using Knudsen Effusion Mass Spectrometry

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 397
Author(s):  
Petroc Shelley ◽  
Thomas J. Bannan ◽  
Stephen D. Worrall ◽  
M. Rami Alfarra ◽  
Carl J. Percival ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Vapour Pressure ◽  
Boiling Point ◽  
Point Method ◽  
Scanning Calorimetry ◽  
Knudsen Effusion ◽  
Pressure Method ◽  
Liquid Saturation ◽  
Knudsen Effusion Mass Spectrometry

Benzaldehydes are components of atmospheric aerosol that are poorly represented in current vapour pressure predictive techniques. In this study the solid state (PSsat) and sub-cooled liquid saturation vapour pressures (PLsat) were measured over a range of temperatures (298–328 K) for a chemically diverse group of benzaldehydes. The selected benzaldehydes allowed for the effects of varied geometric isomers and functionalities on saturation vapour pressure (Psat) to be probed. PSsat was measured using Knudsen effusion mass spectrometry (KEMS) and PLsat was obtained via a sub-cooled correction utilising experimental enthalpy of fusion and melting point values measured using differential scanning calorimetry (DSC). The strength of the hydrogen bond (H-bond) was the most important factor for determining PLsat when a H-bond was present and the polarisability of the compound was the most important factor when a H-bond was not present. Typically compounds capable of hydrogen bonding had PLsat 1 to 2 orders of magnitude lower than those that could not H-bond. The PLsat were compared to estimated values using three different predictive techniques (Nannoolal et al. vapour pressure method, Myrdal and Yalkowsky method, and SIMPOL). The Nannoolal et al. vapour pressure method and the Myrdal and Yalkowsky method require the use of a boiling point method to predict Psat. For the compounds in this study the Nannoolal et al. boiling point method showed the best performance. All three predictive techniques showed less than an order of magnitude error in PLsat on average, however more significant errors were within these methods. Such errors will have important implications for studies trying to ascertain the role of these compounds on aerosol growth and human health impacts. SIMPOL predicted PLsat the closest to the experimentally determined values.

scholarly journals Online gas- and particle-phase measurements of organosulfates, organosulfonates and nitrooxy organosulfates in Beijing utilizing a FIGAERO ToF-CIMS

2018 ◽  
Vol 18 (14) ◽  
pp. 10355-10371 ◽  
Author(s):  
Michael Le Breton ◽  
Yujue Wang ◽  
Åsa M. Hallquist ◽  
Ravi Kant Pathak ◽  
Jing Zheng ◽  
...  
Keyword(s):  
Gas Phase ◽  
Mass Spectrometer ◽  
Glycolic Acid ◽  
Measurement Techniques ◽  
Ambient Air ◽  
Ionization Mass ◽  
Particle Phase ◽  
Acid Sulfate ◽  
Phase Measurements ◽  
Sulfate Production

Abstract. A time-of-flight chemical ionization mass spectrometer (CIMS) utilizing the Filter Inlet for Gas and Aerosol (FIGAERO) was deployed at a regional site 40 km north-west of Beijing and successfully identified and measured 17 sulfur-containing organics (SCOs are organo/nitrooxy organosulfates and sulfonates) with biogenic and anthropogenic precursors. The SCOs were quantified using laboratory-synthesized standards of lactic acid sulfate and nitrophenol organosulfate (NP OS). The variation in field observations was confirmed by comparison to offline measurement techniques (orbitrap and high-performance liquid chromatography, HPLC) using daily averages. The mean total (of the 17 identified by CIMS) SCO particle mass concentration was 210 ± 110 ng m−3 and had a maximum of 540 ng m−3, although it contributed to only 2 ± 1 % of the organic aerosol (OA). The CIMS identified a persistent gas-phase presence of SCOs in the ambient air, which was further supported by separate vapour-pressure measurements of NP OS by a Knudsen Effusion Mass Spectrometer (KEMS). An increase in relative humidity (RH) promoted partitioning of SCO to the particle phase, whereas higher temperatures favoured higher gas-phase concentrations. Biogenic emissions contributed to only 19 % of total SCOs measured in this study. Here, C10H16NSO7, a monoterpene-derived SCO, represented the highest fraction (10 %) followed by an isoprene-derived SCO. The anthropogenic SCOs with polycyclic aromatic hydrocarbon (PAH) and aromatic precursors dominated the SCO mass loading (51 %) with C11H11SO7, derived from methyl naphthalene oxidation, contributing to 40 ng m−3 and 0.3 % of the OA mass. Anthropogenic-related SCOs correlated well with benzene, although their abundance depended highly on the photochemical age of the air mass, tracked using the ratio between pinonic acid and its oxidation product, acting as a qualitative photochemical clock. In addition to typical anthropogenic and biogenic precursors the biomass-burning precursor nitrophenol (NP) provided a significant level of NP OS. It must be noted that the contribution analysis here is only representative of the detected SCOs. There are likely to be many more SCOs present which the CIMS has not identified. Gas- and particle-phase measurements of glycolic acid suggest that partitioning towards the particle phase promotes glycolic acid sulfate production, contrary to the current formation mechanism suggested in the literature. Furthermore, the HSO4⋅H2SO4- cluster measured by the CIMS was utilized as a qualitative marker for acidity and indicates that the production of total SCOs is efficient in highly acidic aerosols with high SO42- and organic content. This dependency becomes more complex when observing individual SCOs due to variability of specific VOC precursors.

Torsion—Knudsen effusion vapour-pressure measurement of o, m and p-chlorobiphenyls

1983 ◽  
Vol 68 (2-3) ◽  
pp. 329-339 ◽  
Author(s):  
Daniela Ferro ◽  
Vincenzo Piacente ◽  
Paolo Scardala
Keyword(s):  
Pressure Measurement ◽  
Vapour Pressure ◽  
Knudsen Effusion ◽  
Vapour Pressure Measurement

scholarly journals Measured solid state and subcooled liquid vapour pressures of nitroaromatics using Knudsen effusion mass spectrometry

2020 ◽  
Vol 20 (14) ◽  
pp. 8293-8314
Author(s):  
Petroc D. Shelley ◽  
Thomas J. Bannan ◽  
Stephen D. Worrall ◽  
M. Rami Alfarra ◽  
Ulrich K. Krieger ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Vapour Pressure ◽  
Scanning Calorimetry ◽  
Subcooled Liquid ◽  
Knudsen Effusion ◽  
Liquid Saturation ◽  
Knudsen Effusion Mass Spectrometry ◽  
Saturation Vapour Pressure ◽  
Selection Of Species

Abstract. Knudsen effusion mass spectrometry (KEMS) was used to measure the solid state saturation vapour pressure (PSsat) of a range of atmospherically relevant nitroaromatic compounds over the temperature range from 298 to 328 K. The selection of species analysed contained a range of geometric isomers and differing functionalities, allowing for the impacts of these factors on saturation vapour pressure (Psat) to be probed. Three subsets of nitroaromatics were investigated: nitrophenols, nitrobenzaldehydes and nitrobenzoic acids. The PSsat values were converted to subcooled liquid saturation vapour pressure (PLsat) values using experimental enthalpy of fusion and melting point values measured using differential scanning calorimetry (DSC). The PLsat values were compared to those estimated by predictive techniques and, with a few exceptions, were found to be up to 7 orders of magnitude lower. The large differences between the estimated PLsat and the experimental values can be attributed to the predictive techniques not containing parameters to adequately account for functional group positioning around an aromatic ring, or the interactions between said groups. When comparing the experimental PSsat of the measured compounds, the ability to hydrogen bond (H bond) and the strength of the H bond formed appear to have the strongest influence on the magnitude of the Psat, with steric effects and molecular weight also being major factors. Comparisons were made between the KEMS system and data from diffusion-controlled evaporation rates of single particles in an electrodynamic balance (EDB). The KEMS and the EDB showed good agreement with each other for the compounds investigated.

scholarly journals Measured solid state and sub-cooled liquid vapour pressures of nitroaromatics using Knudsen effusion mass spectrometry

2020 ◽  
Author(s):  
Petroc D. Shelley ◽  
Thomas J. Bannan ◽  
Stephen D. Worrall ◽  
M. Rami Alfarra ◽  
Ulrich K. Krieger ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Vapour Pressure ◽  
Scanning Calorimetry ◽  
Knudsen Effusion ◽  
Liquid Saturation ◽  
Knudsen Effusion Mass Spectrometry ◽  
Saturation Vapour Pressure ◽  
Selection Of Species ◽  
Major Factors

Abstract. Knudsen Effusion Mass Spectrometry (KEMS) was used to measure the solid state saturation vapour pressure (PSsat) of a range of atmospherically relevant nitroaromatic compounds over the temperature range from 298 to 328 K. The selection of species analysed contained a range of geometric isomers and differing functionalities, allowing for the impacts of these factors on saturation vapour pressure (Psat) to be probed. Three subsets of nitroaromatics were investigated, nitrophenols, nitrobenzaldehydes and nitrobenzoic acids. The PSsat were converted to sub-cooled liquid saturation vapour pressures (PLsat) using experimental enthalpy of fusion and melting point values measured using differential scanning calorimetry (DSC). The PLsat were compared to those estimated by predictive techniques and, with a few exceptions, were found to be up to 7 orders of magnitude lower. The large differences between the estimated PLsat and the experimental can be attributed to the predictive techniques not containing parameters to adequately account for functional group positioning around an aromatic ring, or the interactions between said groups. When comparing the experimental PSsat of the measured compounds the ability to hydrogen bond (H-Bond), and the strength of a H-bond formed appear to have the strongest influence on the magnitude of the Psat with steric effects and molecular weight also being major factors. Comparisons were made between the KEMS system and data from diffusion-controlled evaporation rates of single particles in an electrodynamic balance (EDB). The KEMS and the EDB showed good agreement with each other for the compounds investigated.

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