scholarly journals Clustering, Methodology, and Mechanistic Insights Into Acetate Chemical Ionization Using High-Resolution Time-of-Flight Mass Spectrometry

2016 ◽  
Author(s):  
Patrick Brophy ◽  
Delphine K. Farmer
Keyword(s):  
High Resolution ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Time Of Flight ◽  
Ion Source ◽  
Resolution Time ◽  
Ionization Source ◽  
Targeted Analysis ◽  
The Impact

Abstract. We present a comprehensive characterization of cluster control and transmission through the Tofwerk atmospheric pressure interface installed on various chemical ionization time-of-flight mass spectrometers using authentic standards. This characterization of the atmospheric pressure interface allows for a detailed investigation of the acetate chemical ionization mechanisms and the impact of controlling these mechanisms on sensitivity, selectivity, and mass spectral ambiguity with the aim of non-targeted analysis. Chemical ionization with acetate reagent ions is controlled by a distribution of reagent ion-neutral clusters that vary with relative humidity and the concentration of acetic anhydride precursor. We show that the majority, if not all, ion-neutral chemistry occurs in the ion molecule reactor where incoming sample air mixes with the output of the ion source. Deprotonated carboxylic acids are primarily detected only if sufficient declustering is employed inside the atmospheric pressure interface. The configuration of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) using an acetate chemical ionization source for non-targeted analysis is discussed. Recent approaches and studies characterizing acetate chemical ionization as it applies to the HR-TOF-CIMS are evaluated in light of the work presented herein.

scholarly journals Clustering, methodology, and mechanistic insights into acetate chemical ionization using high-resolution time-of-flight mass spectrometry

2016 ◽  
Vol 9 (8) ◽  
pp. 3969-3986 ◽  
Author(s):  
Patrick Brophy ◽  
Delphine K. Farmer
Keyword(s):  
High Resolution ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Time Of Flight ◽  
Ionization Mass ◽  
Resolution Time ◽  
Ionization Source ◽  
Targeted Analysis ◽  
The Impact

Abstract. We present a comprehensive characterization of cluster control and transmission through the Tofwerk atmospheric pressure interface installed on various chemical ionization time-of-flight mass spectrometers using authentic standards. This characterization of the atmospheric pressure interface allows for a detailed investigation of the acetate chemical ionization mechanisms and the impact of controlling these mechanisms on sensitivity, selectivity, and mass spectral ambiguity with the aim of non-targeted analysis. Chemical ionization with acetate reagent ions is controlled by a distribution of reagent ion-neutral clusters that vary with relative humidity and the concentration of the acetic anhydride precursor. Deprotonated carboxylic acids are primarily detected only if sufficient declustering is employed inside the atmospheric pressure interface. The configuration of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) using an acetate chemical ionization source for non-targeted analysis is discussed. Recent approaches and studies characterizing acetate chemical ionization as it applies to the HR-TOF-CIMS are evaluated in light of the work presented herein.

Non-Targeted chemical characterization of a Marcellus shale gas well through GC  × GC with scripting algorithms and high-resolution time-of-flight mass spectrometry

Fuel ◽  
2018 ◽  
Vol 215 ◽  
pp. 363-369 ◽  
Author(s):  
Paulina K. Piotrowski ◽  
Benedikt A. Weggler ◽  
Erica Barth-Naftilan ◽  
Christina N. Kelly ◽  
Ralf Zimmermann ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Shale Gas ◽  
Marcellus Shale ◽  
Time Of Flight ◽  
Chemical Characterization ◽  
Resolution Time ◽  
Gas Well ◽  
Flight Mass Spectrometry

scholarly journals Detection of atmospheric gaseous amines and amides by a high resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ions

2016 ◽  
Author(s):  
Lei Yao ◽  
Ming-Yi Wang ◽  
Xin-Ke Wang ◽  
Yi-Jun Liu ◽  
Hang-Fei Chen ◽  
...  
Keyword(s):  
High Resolution ◽  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Time Of Flight ◽  
Integration Time ◽  
High Time Resolution ◽  
Ionization Mass ◽  
Industrial Emissions ◽  
Resolution Time ◽  
Ambient Measurements

Abstract. Amines and amides are important atmospheric organic-nitrogen compounds but high time resolution, highly sensitive, and simultaneous ambient measurements of these species are rather sparse. Here, we present the development of a high resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) method utilizing protonated ethanol as reagent ions to simultaneously detect atmospheric gaseous amines (C1 to C6) and amides (C1 to C6). This method possesses sensitivities of 5.6–19.4 Hz pptv−1 for amines and 3.8–38.0 Hz pptv−1 for amides under total reagent ion signals of ~ 0.32 MHz, and detection limits of 0.10–0.50 pptv for amines and 0.29–1.95 pptv for amides at 3σ of the background signal for a 1-min integration time, respectively. Controlled characterization in the laboratory indicates that relative humidity has significant influences on detection of amines and amides, whereas the presence of organics has no obvious effects. Ambient measurements of amines and amides utilizing this method were conducted from 25 July 2015 to 25 August 2015 in urban Shanghai, China. While the concentrations of amines ranged from a few pptv to hundreds of pptv, concentrations of amides varied from tens of pptv to a few ppbv. Among the C1- to C6-amines, the C2-amines were the dominant species with concentrations up to 130 pptv. For amides, the C3-amides (up to 8.7 ppb) were the most abundant species. The diurnal profiles of amines and amides suggest that in addition to the secondary formation of amides in the atmosphere, industrial emissions could be important sources of amides in urban Shanghai. During the campaign, photo-oxidation of amines and amides might be a main loss pathway for them in day time, and wet deposition was also an important sink.

An Iodide-Adduct High-Resolution Time-of-Flight Chemical-Ionization Mass Spectrometer: Application to Atmospheric Inorganic and Organic Compounds

2014 ◽  
Vol 48 (11) ◽  
pp. 6309-6317 ◽  
Author(s):  
Ben H. Lee ◽  
Felipe D. Lopez-Hilfiker ◽  
Claudia Mohr ◽  
Theo Kurtén ◽  
Douglas R. Worsnop ◽  
...  
Keyword(s):  
High Resolution ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Time Of Flight ◽  
Ionization Mass ◽  
Resolution Time ◽  
Inorganic And Organic
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